History Main / SmallRoleBigImpact

* ''Machinima/RedVsBlue'' has [[AmbitionIsEvil Sigma]]. He only appears in a few flashbacks in Season 10 (and died at the end of Season 6), but he's TheManBehindTheMan for the Meta, who is ultimately the reason the plot got anywhere outside of Blood Gulch.

** Wrestling/AliciaFox killed Wrestling/{{Edge}} in 2008. Well, indirectly, and only temporarily. It was the videotape of her being romanced by the Rated-R Superstar on the day of his wedding to then-General Manager of ''[=SmackDown=]'' Wrestling/VickieGuerrero (leaked by Triple H during the ceremony) that caused Vickie to turn vindictively on her fiancé and rehire the Undertaker (who had been [[TenMinuteRetirement permanently banished from WWE about a month earlier]]), whom she then pitted against Edge in a main event Wrestling/HellInACell Match at that year's ''[=SummerSlam=]''. In that match, the Undertaker chokeslammed Edge right through the ring that created a hole, and then caused flames to erupt from it, the implication being that Edge had literally been sent to Hell. But bringing 'Taker back was the worst possible thing that Vickie could have done, since the "Deadman" turned his wrath on her as well as Edge (he having much more reason to hate ''her'', after all). His attempt to choke Vickie's soul out of her body resulted in Wrestling/TheBigShow turning heel to save her, which, in turn, resulted in Big Show becoming Vickie's new boyfriend, until [[JokerImmunity Edge returned]]. This sparked a bitter feud between Undertaker and Big Show that lasted for the rest of the year and continued into 2009 before Vickie and Edge got back together.

* Wrestling/RicFlair is responsible for one of, if not the biggest feud in WCCW history: [[Wrestling/VonErichFamily The Von Erichs]] vs. The Fabulous Freebirds. In a steel cage match between himself and Kevin Von Erich for the NWA World Heavyweight Championship with Michael "PS" Hayes and Terry Gordy serving as the special guest referee and enforcer respectively, Hayes got into an altercation with Flair, which lead to the latter being knocked out by the former. Hayes urged Von Erich to pin Flair, but he refused, [[HonorBeforeReason not wanting to win the championship that way]]. After an argument, [[ScrewThisImOuttaHere Gordy convinced Hayes to just leave him]]. However, Flair would attack Von Erich from behind, inadvertently knocking Hayes out of the cage. [[MistreatmentInducedBetrayal Believing that Von Erich deliberately pushed his friend out of the cage, Gordy slammed the door in his face]], resulting in Flair retaining his championship and the Freebirds and the Von Erichs becoming bitter enemies.

* Wrestling/RicFlair is responsible for one of, if not the biggest feud in WCCW history: [[Wrestling/VonErichFamily The Von Erichs]] vs. The Fabulous Freebirds. In a steel cage match between himself and Kevin Von Erich for the NWA World Heavyweight Championship with Michael "PS" Hayes and Terry Gordy serving as the special guest referee and enforcer respectively, Hayes got into an altercation with Flair, which lead to the latter being knocked out by the former. Hayes urged Von Erich to pin Flair, but he refused, [[HonorBeforeReason not wanting to win the championship that way]]. After an argument, [[ScrewThisImOuttaHere Gordy convinced Hayes to just leave him]]. However, Flair would attack Von Erich from behind, inadvertently knocking Hayes out of the cage. [[MistreatmentInducedBetrayal Believing that Von Erich deliberately pushed his friend out of the cage, Gordy slammed the door in his face]], leaving in Flair retaining his championship and the Freebirds and the Von Erichs becoming bitter enemies.

** Carmella herself is arguably a better example of this, as the reason why the triple threat match happened in the first place was that Paige booked her in a match with Charlotte where the latter would've been added to Carmella's match against Becky Lynch had she won as a response for Carmella taunting that Paige would never win Smackdown Women's Championship due to her CareerEndingInjury. Essentially, the creation of "The Man" was a result of Carmella's KickTheDog moment.

* Wrestling/RicFlair is responsible for one of, if not the biggest feud in WCCW history: [[Wrestling/VonErichFamily The Von Erichs]] vs. The Fabulous Freebirds. In a steel cage match between himself and Kevin Von Erich for the NWA World Heavyweight Championship with Michael "PS" Hayes and Terry Gordy serving as the special guest referee and enforcer respectively, Hayes got into an altercation with Flair, which lead to the latter being knocked out by the former. Hayes urged Von Erich to pin Flair, but he refused, [[HonorBeforeReason not wanting to win it that way]]. After an argument, [[ScrewThisImOuttaHere Gordy convinced Hayes to just leave him]]. However, Flair would attack Von Erich from behind, which inadvertantly knocking Hayes out of the cage. [[MistreatmentInducedBetrayal Believing that Von Erich deliberately pushed his friend out of the cage, Gordy slammed the door in his face]], leaving in Flair retaining his championship and the Freebirds and Von Erich becoming bitter enemies.

** When Rocky added Wrestling/OwenHart into The Nation, it was to get backup in his feud with Wrestling/DGenerationX. This would lead to one of the biggest and most recurring rivalries in Wrestling/{{WWE}} history, between The Rock and Wrestling/TripleH.

** The [=MUTOs=] (Hokmuto and Femuto) serve as the {{Big Bad}}s of ''Film/Godzilla2014'', and although they die at the movie's end, their rampage is directly responsible for TheUnmasquedWorld in all [=MonsterVerse=] instalments set afterward.
** In the 2014 movie's prequel graphic novel ''Godzilla: Awakening'', it's revealed that the franchise's main [[TheTeam Team]] organization Monarch was founded not because of Godzilla's emergence, but because of the rampage of the novel's Kaiju antagonist Shinomura, who died at the novel's end. Monarch didn't become aware of Godzilla's existence until later.
** In the ''Film/GodzillaVsKong'' prequel ''Kingdom Kong'', the Kaiju antagonist is Camazotz. Although this is Camazotz' only in-the-flesh appearance thus far, it's revealed here that he's responsible for the destruction of the franchise-central EldritchLocation Skull Island before the start of the movie, which in turn forces Kong to find a new home in the HollowEarth.

* Franchise/MonsterVerse:

** Grimesby Roylott/[[spoiler:Nikolina Pavlova]] only appears in one case of ''VisualNovel/TheGreatAceAttorney'', but has a great impact on the course of the story [[spoiler:She accidentally pushes Kazuma and seemingly kills him, resulting in Ryunosuke taking his place as a defense attorney. This would seem like a large enough impact, but it later turns out that Kazuma had agreed to come to Japan in order to assassinate Inspector Gregson, and the fact that Ryunosuke had no knowledge of the plan, let alone the willingness to carry it out, forced Seishiro Jigoku to personally kill Gregson in the final case, resulting in Ryunosuke exposing Jigoku as a murderer and unraveling the Reaper conspiracy.]]

** The first one was Faarooq hiring then unproven newcomer Rocky Maivia. The young athlete would undergo a FaceHeelTurn and transform into [[Wrestling/DwayneJohnson The Rock]], who would (a) [[DragonAscendant strip Farooq out of the leadership]], (b) become one of the two biggest stars of the Wrestling/AttitudeEra, (c) become a multi-time WWE World Heavyweight Champion, and (d) transition into one of the most [[Creator/DwayneJohnson popular actors]] of the 21st century.
** When Rocky added Wrestling/OwenHart into The Nation, it was to get backup in his feud with Wrestling/DGenerationX. This would lead to one of the biggest and most reoccuring rivalries in Wrestling/{{WWE}} history, between The Rock and Wrestling/TripleH.

An inadvertent blow to the neck from Wrestling/TheBigShow nearly crippled her, turned boyfriend Wrestling/DanielBryan into an overprotective and possessive jerk, and ultimately caused Bryan to lash out at Lee for nearly everything she did, including his losing the World Heavyweight Championship in 18 seconds to Wrestling/{{Sheamus}} at ''Wrestling/WrestleMania'', thus leading Bryan to virulently dump AJ on the following week's episode of ''Wrestling/WWESmackDown''. Daniel's cruelty apparently caused AJ's mind to snap, [[SanitySlippage resulting in her behavior becoming ever more erratic]] and her profile on television to rise, as airtime was steadily eaten up by her bizarre antics. Indeed, AJ was transformed into such an outrageous scene stealer that Wrestling/VinceMcMahon appointed her as General Manager of ''Wrestling/WWERaw'' later that summer -- much to the chagrin of Daniel Bryan, who had assumed that she had agreed to marry him in the ring when in fact she had accepted the GM position.\\
This cruel prank, in turn, caused Bryan to lose his mind, which in turn led to him having to seek psychological group therapy along with Wrestling/{{Kane}}... which culminated in the two of them forming a comedic tag team called Wrestling/TeamHellNo that [[HeelFaceTurn turned both characters face again]]. This marked the beginning of Daniel Bryan's true rocket to stardom in WWE, making him so popular that not only did he go on to win the WWE Championship three times, but when he was respectively excluded from and (relatively) quickly eliminated in the 2014 and 2015 Wrestling/RoyalRumble matches, fan disillusionment ran so deep that the WWE Universe turned virulently on the men who did win those matches: Wrestling/{{Batista}} and Wrestling/RomanReigns. While Batista turned this situation into heel heat for what eventually led to Bryan's title win at ''[=WrestleMania=] 30'', Reigns never regained the adoration he had during his days with Wrestling/TheShield, [[XPacHeat is still heavily booed despite being a face]], and has had to acknowledge that fact within kayfabe.\\

** Wrestling/{{Paige}}'s actions as ''[[Wrestling/WWESmackdown Smackdown Live!]]''[='=]s General Manager played a huge role in the creation of [[Wrestling/BeckyLynch "The Man"]]. She booked a Triple Threat match where the champion Wrestling/{{Carmella}} would face Becky and Wrestling/CharlotteFlair for ''Wrestling/{{Summerslam}} 2018''. At the end of said match, with Charlotte stealing the victory and the championship from her hands at the last minutes of the match, and feeling that everything she worked for has been stolen again, Becky [[FaceHeelTurn turned heel]] on Charlotte, and their friendship was destroyed. This, in turn, would lead to the revamp of Becky as a Wrestling/StoneColdSteveAustin-like character (with the audience ''refusing'' to boo her), a series of well-received matches against Charlotte (including a [[Wrestling/TheWrestlingObserverNewsletter four-and-three-quarter-star-rated]] Last Man Standing match at ''WWE Evolution''), the Twitter feud with Creator/RondaRousey, Becky being injured by Wrestling/NiaJax in the ''Raw'' go-home episode for ''Wrestling/SurvivorSeries 2018'' (and the resulting injury from Nia's botch making Becky look like a warrior), Becky being left out of ''SS'' due to said injury, and the main event of ''Wrestling/{{WrestleMania}} 35'' being changed from Ronda vs. Charlotte into a Triple Threat match with Becky inserted as a challenger between the two champions in a "Winner Takes All" match... which she won, resulting in Becky being the first Women's Champion holding both the Raw and Smackdown Women's titles at the same time and becoming [[TheAce the new face]] of [[Wrestling/WWENewEra the WWE's "New Era"]]. Oh, and if that wasn't enough, in RealLife, her new persona being called "The Man" led to a series of Twitter quips with Wrestling/SethRollins, who also called himself "The Man"... and who eventually not only would become his boyfriend, but also the father of her child.

** The first one was Faarooq hiring then unproven newcomer Rocky Maivia. The young athlete would undergo a FaceHeelTurn and transform into [[Wrestling/DwayneJohnson The Rock]], who would a) [[DragonAscendant strip Farooq out of the leadership]], b) become one of the two biggest stars of the Wrestling/AttitudeEra, and c) become a multi-time WWE World Heavyweight Champion.

* "ComicBook/GreenArrow" in "ComicBook/BatmanTheDarkKnightReturns" shows up very late into the comic book (and animated adaptation), but shoots a Kryptonite-tipped arrow which is central to weakening Superman before the end of his fight with Batman.

* In ''WesternAnimation/MarvelRisingSecretWarriors'', [[spoiler: Captain America]] only appears for a minute at the end of the movie, but he indirectly helped form the team.

[[folder:Anime & Manga]]
* ''Manga/The100GirlfriendsWhoReallyReallyReallyReallyReallyLoveYou'': The God of Love shows up in the first chapter, is limited to making cameos in the volume extras from that point on and doesn't reappear until Chapter 85. Yet it's only because he got distracted by ''Anime/CastleInTheSky'' while filling out Rentarou's soulmate count that Rentarou has one hundred girlfriends.
* ''LightNovel/ArifuretaFromCommonplaceToWorldsStrongest'': Aiko's apperances in the light novel can be counted on one hand, yet it's because of her that Hajime went from being from a very selfish anti-hero into someone willing to help others to avoid living "a lonely life".
* ''Manga/AttackOnTitan'':
** [[spoiler:Grisha Jaeger]]. No one has seen hide nor hair of him since very early in the series. Even so, [[spoiler:it's heavily implied he knows many mysteries about the Titans, and is the one who gave Eren his Titan shifting powers via a mysterious injection. All of this is confirmed through a flashback, [[ThanatosGambit plus the reason why he isn't there]].]]
** Perhaps even more so is [[spoiler:Eren Kruger]], who only appears in the flashbacks of the character mentioned above, but is essentially responsible for all the events in the series turning out the way they did -- [[spoiler:Grisha met Kruger when he was a child and was present on the day Grisha's sister was killed. He's the reason why Grisha joined LaResistance and met his first wife Dina and it's because of him that Zeke Jaeger, the Beast Titan, was born. Zeke then betrayed his parents and they ended up on Paradis Island with the other members of their group. Kruger was then the one who saved Grisha's life and gave him the powers of the Attack Titan, which Grisha then bequeathed to his son]]. [[UpToEleven To top it all off]], he's ''also'' the inspiration behind [[spoiler:[[DeadGuyJunior the protagonist's name]]]]. Safe to say that the story would be ''very'' different if he and [[spoiler:Grisha]] had never met.
* ''Manga/{{Beastars}}'': Zoe is an extremely minor goat character that most people don't even know the name of. But if he hadn't went looking for Legosi right when he did, Legosi would have eaten Haru, resulting in a very, very different story than what we got.
* Dying Breed rarely appear in ''Manga/{{BECK}}'', but they inspire both Ryuusuke and Koyuki to push the band to great heights, and [[spoiler: Eddie Lee's death]] causes a HeroicBSOD from almost the entire music world. Not only that, but rumors of an unreleased song of theirs drive a huge portion of the plot.
* ''LightNovel/BeingAbleToEditSkillsInAnotherWorldIGainedOpWaifus'':
** The Dark Elf mother and her child only appear very briefly in the manga, but it's only because Rita stopped the caravan in order to help them that Nagi learned about the Leviathan in the first place.
** Astarte shows up at the start of the story, guides Nagi to Cecil, and then is never seen or heard again once Nagi buys her. Yet if it had stayed silent, Nagi's prospects in this new world would have been quite grim, and Cecil would still be a "useless Dark Elf" slave, waiting for death in a cell.
* ''Manga/{{Berserk}}'' has Adonis, the son of Count Julius and cousin to Princess Charlotte. He gets little to no lines and his only purpose is to get killed by Guts, when he ends up seeing his father getting killed by him. But Guts is clearly broken up about killing the kid, which is among the reasons that he decides to leave the Band of Hawks, and Griffith, to pursue his own dream. And that decision ended up influencing Griffith so far that it spiraled out of control and into the events of [[FromBadToWorse The Eclipse]].
* ''Manga/CaseClosed'':
** Narumi Asai was only in one case ("Moonlight Sonata"), but the strong impact it had on Conan/Shinichi cannot be understated. This case haunts Shinichi as the first time he was faced with a [[spoiler:suicidal culprit]] whom he was unable to save.
** Asami Uchida makes an appearance in one case, but thanks to her, it's now known that Ran is Shinichi's {{first love}}.
* ''Manga/ChoujinSensen'': Even though Haruna is no more than LoveInterest of Tomobiki, it was her that encouraged Tomobiki to search up the [Superhuman Game] online and participate the death match (although Tomobiki didn't exactly expect that his life is on the line). You can say that she's the whole reason why Tomobiki starts to fight for his (somewhat pathetic) life.
* Interestingly enough, despite being the protagonist in ''Anime/CodeGeass'' in the side story ''Anime/CodeGeassAkitoTheExiled'' "[[BrainwashedAndCrazy Julius Kingsley]]" aka [[AntiHero Lelouch]] is this. He's only really involved during the third OVA, but without the impact of the [[FalseFlagOperation Ark Fleet]] and his coup against the Grand Duke of Euro Britannia, neither [[spoiler: Gene Smilas]] or [[AxeCrazy Shaing]] could have gotten their plans off the ground so quickly, which resulted in the climax in canon and likely the EarnYourHappyEnding that Akito and co got.
* In ''LightNovel/DeathMarchToTheParallelWorldRhapsody'', Hikaru, the programmer that disappears before the story begins. Without Hikaru helping, [[TheHero Ichiro Suzuki]] is forced to do a programming "Death March" of 80+ work weeks to meet a deadline to finish a game. When he finishes and falls asleep, the next he knows is that he has been returned to his 15-year-old body and sent to the fantasy world where the entire story takes place.
* In ''Manga/DeathNote'':
** Lind L. Tailor's brief introduction and death allows L to track Light to the region of Japan he lives in, alongside showing both L and Light what the other is capable of.
** SPK agent Stephen originally seems like another background character who doesn't accomplish much, except for the finale when it's revealed that [[spoiler:Stephen was able to perfectly replicate Mikami's Death Note. This skill causes Mikami to make a mistake that outs Light to Near, leading to Light's death and the final end of Kira's reign of terror]].
** Misa's stalker. He doesn't even have a name in the manga or anime, but if not for him [[spoiler:Gelus, a shinigami, wouldn't have died saving Misa's life. And Misa never would've received his Death Note from Rem. Without Misa as the second Kira]], most of the story would've played out differently.
* In ''Manga/DemonSlayerKimetsuNoYaiba'':
** At the start of the series, Tanjiro is on his way back home from selling charcoal when an old man named Saburo insists that he stay the night at his house, since it's getting dark and demons attack at night. Tanjiro accepts despite not believing in the existence of demons, and this saves him from [[BigBad Muzan Kibutsuji's]] attack on his family, which resulted in Tanjiro's sister Nezuko being turned into a demon and the rest of the family being killed. Tanjiro's survival sets him on the quest to return his sister to being human, resulting in him becoming a Demon Slayer and TheHero of the story.
** [[spoiler:Kyojuro]] is the first Hashira the main trio: Tanjiro, Zenitsu and Inosuke are officially drafted on a mission with, [[spoiler:Kyojuro dies on that same mission, but he]] leaves quite the impression on Tanjiro, as a mentor figure and friend; [[spoiler:while not performers of the same Breathings, Flame Breathing and Hinokami Kagura had its synergy with Tanjiro first thinking Kyojuro would have the answers to know more about his new Breathing, but even if the Breathings weren't the same Kyojuro's flaming determination became a part of Tanjiro quite literally, as Kyojuro's original sword guard was preserved and then embedded on Tanjiro's fourth sword in the series. Kyojuro's death is also the first one Inosuke reacts with proper sorrow.]]
* ''Anime/DigimonTamers'':
** [=IceDevimon=] was a MonsterOfTheWeek who kidnapped Rika with the intent of making her his Tamer. While he was destroyed at the end of his episode, Rika's encounter with him was so traumatizing that she declared her hatred of all Digimon including her own partner Renamon. She and Renamon wouldn't reunite until an episode later, which was the beginning of a massive change in Rika's attitude towards Renamon and Digimon as a whole.
** [[EasternZodiac The Horse Deva]], Indramon, only appeared in two episodes, the second of which was his death. However, his vicious beatdown on Impmon set in motion the events that led to Impmon making a deal with the Devas to become Beezlemon.
* ''Franchise/DragonBall'':
** Grandpa Gohan is dead by the original ''Manga/DragonBall'''s beginning and only appears in person during the Fortuneteller Baba Saga, but it was his finding Goku and raising him that turned Goku from the future destroyer of humanity to the altruistic AllLovingHero we know and love. Furthermore, Goku's first born son is [[DeadGuyJunior named in his honor]].
** Believe it or not, Raditz is essentially the catalyst for the entire second half of the ''Dragon Ball'' manga (or ''Anime/DragonBallZ'', as it's usually named). Had Raditz not remembered his little brother and come to Earth, the entire series would have been turned on its head: Piccolo and Goku would never have teamed up and thus Piccolo wouldn't have joined the Z-Fighters. He may have even remained evil, and continued on with a plan to terrorize planet Earth, had he and Goku not joined forces. Goku wouldn't have trained with King Kai, but merely at his own pace, and would have been far too weak to combat the androids by the time they arrived, assuming he hadn't already died from the heart virus he was to contract. Gohan would never have been trained by Piccolo, and thus would never have become a fighter at all. Vegeta and Nappa would never have received the transmission involving the Dragon Balls, and thus would never have visited the Earth, thus remaining under Freeza's thumb -- Freeza himself would also never have been killed, allowing the Cold family to continue terrorizing the universe. And who knows what trouble Babidi would've caused if he'd arrived earlier and unleashed Buu unchallenged. Despite being the weakest villain at the start of the series, Raditz coming to Earth is what allowed the Z series to be what it became.
** Dr. Gero. He's long dead in Trunks' timeline and is only around for a few episodes as Android 20 before being killed by Android 17. However, it is Gero who created all the androids, including Cell, and his actions turns two timelines into a living hell and nearly destroys the solar system of the main timeline. Literally ''everything'' bad that happens in the Android/Cell Saga is his fault.
*** Gero is also an example of RememberTheNewGuy. He is a member of the Red Ribbon Army, a major villains faction from the original ''Manga/DragonBall'' series and was the creator of Android 8, the first successfully created Red Ribbon android and the first one the heroes faced. However, Gero wasn't seen or mentioned until the Android Saga years later in real life.
*** And then in ''Anime/DragonBallSuper,'' even though Gero's creations aren't actually involved, the entire Future Trunks saga where Goku Black and Zamasu wreak havoc on the future timeline was caused because Bulma invented time travel to undo the damage left behind by the Cyborgs/Androids. [[spoiler: And on the bright side, Dr. Gero also indirectly ''saved the multiverse'' by creating Androids 17 and 18, who were key players in the Universe Survival tournament, with the former ending up the ultimate victor and passing the SecretTestOfCharacter behind the tournament by wishing for the others' return.]]
** Bibidi is long dead by the time the Buu saga begins, and only a late anime flashback shows what he even looks like, but he's the one who instigated it by summoning Majin Buu in the first place. And while his 'son'/doppelganger Babidi is continuing the plan in his place, Babidi doesn't have all of Bibidi's knowledge, and so doesn't know the spell that actually ''unseals'' Buu, forcing him to steal energy to do it. Babidi is also verbally abusive to Buu and controls him through the threat of being sealed away, unlike Bibidi who preferred to use cake as a reward, which got him killed when Buu finally made it clear that he didn't appreciate the poor treatment.
** Van Zant, the AxCrazy gunman who shot Mr. Satan and Bee, triggers the latter half of the Buu Saga. He only appears in two episodes, and isn't even named in the manga, but his attack on Mr. Satan and Bee, whom Majin Buu had befriended, directly results in the creation of [[LiteralSplitPersonality Evil Buu]], who in turn eats his good half and becomes Super Buu.
** The Yardrat race barely appears in the anime and not at all in the manga, but them teaching Goku Instant Transmission off-screen ends up saving the earth several times over.
** Similarly, the Metamoran race never shows up, even in the anime, but they taught Goku the TropeNamer for FusionDance, which he passes on to Goten and Trunks.
** As of ''[[Manga/JacoTheGalacticPatrolman Dragon Ball Minus]]'' and ''Anime/DragonBallSuperBroly'', Bardock and Gine. They were the ones to send Goku to Earth. If they hadn't, Goku would have died along with their planet. And without Goku, Pilaf would've become ruler of earth thanks to the Dragon Balls.
** Lord Zuno, the smartest being in the universe; despite him showing up for only two scenes in the Future Trunks Saga, it's him telling Zamasu about the Super Dragon Balls and Goku that gives Zamasu the information needed to begin his plans, [[spoiler: first by killing his master to become a Supreme Kai and taking the Time Ring, using it to go a year into the future, and making a wish on the Super Dragon Balls to take Goku's body, creating Goku Black]].
** In ''Anime/DragonBallSuper'', the three muggers who try to [[spoiler:rob Goku unknowingly cause the Universe Survival arc.]]
* ''Manga/ElfenLied'':
** Tomoo appears in one episode and one manga chapter, but it was his actions that ultimately played the biggest role in turning Lucy into a bitter figure who hated humanity (namely he beat her puppy to death with a rock/vase and [[ForcedToWatch made Lucy watch when he did]]). Lucy snapped and brutally executed him and his cronies, as well as someone who may or may not have meant to betray her. It was all downhill from there.
** Speaking of someone who may or may not have meant to betray Lucy, the unnamed "orphanage girl" also has a small role, but has just as big an impact on the plot as Tomoo: the reason Tomoo found out that Lucy even had a puppy was because the orphanage girl told him about it, even though the orphanage girl had previously promised Lucy to keep the puppy's existence a secret. So while Tomoo's murder of a puppy sent Lucy down the path of misanthropy, it was the unnamed orphanage girl who made Tomoo's actions possible. The girl later claims that she blabbed about the puppy by accident, but Lucy thinks the girl betrayed her on purpose out of malice. It's left ambiguous which interpretation is correct.
** Aiko Takada has an equally brief appearance, but she's Lucy's second human friend, and it was her death that resulted in Lucy being captured and imprisoned in the Diclonius Research Institute, as well as the catalyst for Lucy's long-running vendetta with Kurama.
** Diclonius Silpleit # 3 died quickly in a flashback, but not before infecting Kurama and his original assistant with the virus that caused their children to be born Diclonius. This led to Mariko's birth, the realization of the manner of Diclonius propagation, and down the line, the existence of Lucy.
* ''Manga/FlyMeToTheMoon'' has Iwakasa, a subordinate of the Emperor in Princess Kaguya's time [[spoiler:and Tsukasa's father]]. The Emperor told him to burn the immortality-granting Hourai Elixir, but instead, Iwakasa gave it to his daughter, [[spoiler:resulting in Tsukasa becoming immortal, thereby living long enough to meet Nasa]]. Because of him, the entire plot became possible.
* Kyoko Honda from ''Manga/FruitsBasket'' is a PosthumousCharacter when the story begins and she only appears during flashbacks, but her influence is felt through her daughter Tohru's idealism and a few other characters she helped before she died. [[PlotTriggeringDeath Her death]] is also what essentially kicks off the plot, as Tohru would likely never have become involved with the Sohma clan otherwise.
* ''Manga/FullmetalAlchemist'': [[spoiler:Nina Tucker]] clearly plays a very significant role in the Elric brothers' lives for someone who died so early in their career. Additionally, the element [[spoiler:she]] was connected to, chimeras, comes up again and again in the series.
* ''Franchise/{{Gundam}}'':
** Gene in ''Anime/MobileSuitGundam''. He's a random Zeon {{Mook}} killed in the first episode, but his decision to disobey orders and attack the Project V mobile suits is what causes Amuro to hijack the Gundam and consequently set off much of the UC in motion.
** [[AntiVillain Crank Zent]] in ''Anime/MobileSuitGundamIronBloodedOrphans''. He's a Gjallarhorn officer who [[WouldNotHurtAChild refused to harm the children in CGS base]] and was [[MercyKill mercy killed]] by Mikazuki in the third episode, but his death was the driving force of [[FromNobodyToNightmare Ein Dalton's]] vow on "[[RevengeBeforeReason absolving]]" [[WouldHurtAChild the sinful children who killed Crank]].
** Eve in ''Anime/GundamBuildDiversReRise''. She only shows up in flashbacks, implied to be dead at the start and [[ArsonMurderAndJaywalking and her name]] [[AllThereInTheManual is only listed on the series' Japanese webpage]]. But, her existence is what drives Hiroto throughout Season 1 of the series and gives meaning to his Gunpla's armor system.
* Hayate's parents in ''Manga/HayateTheCombatButler'', who only appear a few times in flashbacks [[spoiler: at least until the very end of the manga]] and don't even have faces, but their [[AbusiveParents monstrous negligence and abuse]] of Hayate is ultimately what turned him into a BrokenAce, and both directly led to him [[spoiler: meeting Athena and thus learning all of his combat skills]] and eventually trying to kidnap Nagi, which then led to him becoming her butler.
* In ''Manga/{{Hinamatsuri}}'', Atsushi is a background character, but the existence of the BadFuture Hina and friends comes from depends on whether he [[PuttingTheBandBackTogether reunites with his old bandmates and gets back into music]] or not. The last major arc in the manga is all about the girls managing to get him to rediscover his old passion for music so they can live a peaceful life.
* ''Manga/IBelongToTheBaddestGirlAtSchool'': Tsukaji is a very minor character, yet she's the catalyst for [[spoiler: Kanade giving up her position as Banchou for a time]].
* ''Manga/{{InuYasha}}'':
** The [[HotWitch dark priestess]] Tsubaki is only around for five episodes, and appears in flashbacks in two more, but she is the one who placed the curse on Kikyo which ended up weakening her spiritual powers, leaving her vulnerable to Naraku's attack which led to her death and Inuyasha being framed and pinned to a tree for fifty years.
** The demon {{necromancer}} Urasue is only around for two episodes, but she has quite the impact on the series, having been the one to resurrect Kikyo.
** The moth demon bandit Gatenmaru only appears in two episodes as well, but he forces Inuyasha into his SuperpoweredEvilSide, resulting in his death and the deaths of quite a few of his [[HumansAreBastards human minions]]; it's this incident that finally convinces Inuyasha to give up his plan of using the Shikon Jewel to become a full-fledged demon.
* Admiral Robert J. Hanner, United Planets Space Force (ret.), from ''Anime/IrresponsibleCaptainTylor'' appears only about four times in the 26 episode series, and only once in a speaking role. However, directly or indirectly, he's responsible for Tylor becoming a starship captain, the ''Soyokaze'' crew getting demoted, the war with the Raalgon being able to conclude without additional bloodshed, and his death sparks a HeroicBSOD from Tylor.
* ''LightNovel/InvadersOfTheRokujyouma'': Yuuichirou Satomi, Koutarou's father, doesn't appear often, but it's only because Koutarou wanted to lessen his father's burden following his mother's death that he moved into Room 106 and met the girls in the first place.
* ''Manga/JoJosBizarreAdventure'':
** A petty thief named Dario Brando [[AbusiveParents abused his only son]] [[UnwittingInstigatorOfDoom and treated him like crap]]. Imagine for a second; if this petty pick-pocket, a nobody in the grand scheme of the universe, had instead been a DotingParent who worked hard and treated his family with kindness all his life, ''Dio Brando'', The Tyrant [[spoiler:who remade The World]], would have grown up to be just another honest yet equally faceless laborman in Victorian London, and more importantly; the Joestar/Kujo family's legacy as Warriors and Heroes would never have been awakened without him finding George, accidentally saving his life, which in turn led to Dio's vicious bullying of Jonathan in childhood. Like-father Like-Son, after all. Though, even if the Joestar/Kujo's legacy would never awaken, no threats would come to the world because Dio would grew as a honest man.
** An even more extreme example would be the nameless vagrant who harassed Dio and became the first victim of the Stone Mask. His transformation into a vampire was what gave Dio the idea to use it on himself, and subsequently become an immortal menace who haunted the entire Joestar line.
** After the battle against Dio ended, a nameless vampire managed to escape detection, and became an officer in the British air force. He killed George "Jorge" Joestar II- Jonathan's son and Joseph's father -- when George uncovered is identity, and while George's widow Elizabeth was able to kill him, it resulted in her being wanted as a murderer and having to go into hiding as Lisa Lisa. Because of one minor character who's dead by the start of Part 2, Joseph never knew his parents for much of his childhood.
** Gray Fly is the StarterVillain of Part 3, who attacks the protagonists while they're on a plane out of Japan, and he is never mentioned after his defeat. However, were it not for him, the epic quest across multiple countries that makes up the bulk of the story would have been reduced to a mere plane flight and ended in a few days. The reason is because his actions caused the plane to crash and endangered the lives of the passengers, the protagonists realize that they can't risk getting civilians caught up in their battles, even it forces them to take a longer route to Egypt.
** Enyaba appears for a few scenes in Part 3 and [[spoiler:is killed by DIO in her first major appearance.]] She is also the reason DIO managed to awake his Stand, The World, thanks to her [[spoiler:buying the Stand Arrows from an Italian mafia boss (As revealed in [[Manga/JoJosBizarreAdventureGoldenWind Part 5]])]], and it's heavily implied that much of DIO's knowledge of the Stand phenomenon come from her teachings, meaning that if it wasn't for Enya, DIO and none of the Joestars would have awakened their Stands, [[spoiler:and DIO wouldn't have known about "heaven", meaning that [[UnwittingInstigatorOfDoom she is the main reason]] for the DownerEnding of [[Manga/JoJosBizarreAdventureStoneOcean Part 6]]]]. Which is pretty impressive, as she was only a ClimaxBoss.
** Leaky-Eye Luka in Part 5. He only appears for one chapter, has no stand ability, and pretty much defeats himself, but his death is what causes Bucciarati to track down Giorno, resulting in the plot between the two of them to take over and reform Passione that drives the rest of the storyline.
*** Similarly in Part 5, Polpo appears in only two scenes (''his own stand'' has more page-time than him), but his death drives the plot just as much as Luka's, both in the revelation that he had a massive treasure hoard hidden away (that Bucciarati uses to boost themselves to Operator status) and the revelation that he was responsible for protecting Trish, the daughter of TheDon of Passione. After his death, Bucciarati and his team are tasked with protecting Trish.
* Setsuko Sasaki, the president of the fledging Occult Club of Yuji Itadori's school in ''Manga/JujutsuKaisen'' may have vanished from the plot after the Introduction Arc, but her attempting to unseal one of Sukuna's fingers is what kickstarted the plot.
* ''Franchise/KagerouProject'': Tsukihiko, Azami's husband, appears very briefly in the anime, and in only one of the music [=PVs=], yet his love and acceptance of Azami was what led her to develop her own emotions, resulting in the creation of the Heat Haze World and [[spoiler:the [[EmotionBomb Favouring Eyes Snake]], born of her love for her husband and child, and [[ForWantOfANail the snake that is the key to saving everyone]]]]. Azami herself could count, as she is the source of the main cast's powers [[spoiler:and the grandmother of Marry]], and she appears nearly as little as her husband does.
* ''Manga/KaguyaSamaLoveIsWar'':
** The Mass Media Club president only shows up twice before graduation, and the only time she actually does something is during a flashback where she falls in a swamp and nearly drown. Despite this, she has a major influence on the overall story since [[spoiler:[[SamaritanRelationshipStarter Kaguya rescuing her is what caused Shirogane to fall in love in the first place]]]]. She has a slightly larger presence in the ''We Want to Talk About Kaguya'' spin-off (as the main characters there are both members of her club), but she still mostly stays in the background.
** [[BitchInSheepsClothing Ogino]] only shows up in 3 chapters (and all those appearances are in flashbacks), but he's single-handedly responsible for turning Ishigami into the person he was at the beginning of the manga.
** The previous StudentCouncilPresident also never shows up outside of flashbacks (barring an EarlyBirdCameo in episode 17 of the anime and a brief scene during the seniors' graduation), yet his actions led to the story's two longest ongoing plotlines. Shirogane never would have fallen in love with Kaguya [[spoiler:if he hadn't reached out to him and taken him to the swamp the Mass Media Club president fell in on that fateful day]], and Tsubasa never would have confessed to Kashiwagi if he hadn't established the practice of allowing students to seek advice from the Student Council.
* Nanami's father from ''Manga/KamisamaKiss'' only appears in the first chapter and a few flashbacks, but it's him running away to escape his gambling debt that leads to Nanami becoming homeless and accepting a strange man's offer of giving her his home. The home turned out to be a shrine, and by giving it to her, he made her the new kami. The plot is about her dealing with this position.
* ''Anime/KikisDeliveryService'' has Madame's granddaughter who is notable for being a RichBitch and a {{Foil}} against the much kinder grandmother. She is such a brat that she inspires Kiki's bad mood, which mixed with a long miserable flight home causes Kiki to be late to Tombo's party and being sick the next day. Later on, the granddaughter's reappearance as one of Tombo's acquaintances during Kiki and Tombo's outing sours Kiki's relationship with Tombo and also causes her to lose her powers.
* ''Manga/KomiCantCommunicate'' implies that this is the case for Gorimi Senpai. It's hinted that Agari being her understudy library chief is why Agari has gained some agency and self-esteem.
** Ai doesn't show up much, yet it's partly because of her constant bullying that Makoto is both super buff and super shy.
** If Seikimatsu Toshio hadn't elbowed Tadano unconscious in Chapter 4, Komi wouldn't have stayed behind in the classroom or had the conversation that lead to Tadano becoming her first friend. Yet Seikimatsu makes very few appearances in the story.
* ''Franchise/LyricalNanoha'':
** The [[{{Cyborg}} Number]] Due from ''Anime/MagicalGirlLyricalNanohaStrikers''. Despite being the most minor of the twelve Numbers, she's responsible how the BigBad Jail Scaglietti got Olivie Sägebrecht's DNA and could create the Sankt Kaiser's clone Vivio Takamachi, who is the Vessel of the Saint's Cradle and the main character of ''[[Manga/MagicalGirlLyricalNanohaViVid ViVid]]''. Due was Quattro's mentor, the most vicious of Scaglietti's three CoDragons, who inherited many traits of Due's psyche and personal ambitions as a result of the time that they spent together. She also provides BadGuysDoTheDirtyWork by [[spoiler:killing the TSAB High Council and Regius Gaiz, which goes a long way towards making sure the Bureau doesn't repeat their mistakes]].
** The three unnamed girls who bullied Rinne in ''Anime/VividStrike'' only show up during a single episode in a flashback, but literally every bad thing that happens during the season proper (save for Fuka being fired from her job) can be directly traced back to them since pretty much all of Rinne's actions are influenced by the emotional scars they left on her.
* Gai Daigouji in ''Anime/MartianSuccessorNadesico'', a SacrificialLion only lasts for 3 episodes before dying a tragically ignoble death. His death, however, has a lasting impact on main character Akito, and he's the guy who introduces [[ShowWithinAShow Gekiganger 3]] to the crew of the Nadesico, [[spoiler: which becomes very important when it turns out that the "Jovian lizards" have based their entire culture around it.]]
* The bandit from ''Manga/MissKobayashisDragonMaid''. She only shows up in a single chapter as part of a flashback and isn't even given a name, but meeting her changed Tohru's entire world view and is a big part of the reason why Tohru became Kobayashi's maid.
* ''Manga/MyHeroAcademia'':
** The Sludge Villain from early on in the series is such a StarterVillain that he doesn't even get a proper name in the story, yet his role is crucial, allowing the protagonist, Izuku Midoriya, to meet his idol as well as inherit his superpowers, in addition to providing an initial wake-up call for Bakugo that he's not as [[SmallNameBigEgo big a badass as he thinks he is.]]
** Stain, the HeroKiller, while a fan-favorite and a ''massive'' KnightOfCerebus, was still ultimately an ArcVillain, who was defeated in his first on-screen battle before being sent to [[HellHolePrison Tartarus Prison]] for the rest of the series. However, his impact on the story and setting were ''massive'', having inspired dozens of new villains with his philosophy. Of those he inspired, many, like [[{{Yandere}} Toga]] and [[PlayingWithFire Dabi]], would join [[BigBad Shigaraki]]'s League Of Villains due to the misconception that he was a member of the League, something that Shigaraki capitalized on. Allowing them to become prominent recurring villains. What's more, the intensity of his beliefs were what drove Shigaraki to develop a solid philosophy and goals of his own, which was when he started growing out his PsychopathicManChild tendencies, and into a ''much'' more dangerous villain. And all of this was caused solely by Stain's ''reputation''.
** Doctor Tsubasa can be considered this for being the one to tell Midoriya that he doesn't have a quirk, and thus drastically affect Midoriya's life, views, and relationships from that point onward. 'Can be' being the key word, as a doctor looking very much like him was shown [[spoiler: as All for One's physician]], up to sharing voice actors, leaving it ambiguous just how small his role in the story is.
** The Chainsaw Nomu that appears in the Training Camp arc, chases Yaoyorozu and Awase around a bit, and then leaves. But before he does, the two are able to attach a tracking device to him, leading the heroes right to the Nomu Factory, which in turn sets up events with ramifications throughout the rest of the story.
** Kotaro Shimura is a PosthumousCharacter, but his influence can be felt in the whole manga, as [[AbusiveParents his treatment]] turned his son Tenko Shimura from a sweet child [[spoiler: alongside All For One into the BigBad Tomura Shigaraki.]]
** The Fourth Torchbearer of One for All, Hikage Shinomori. He only shows up along with the other Torchbearers in Izuku's mindscape, and never fought All for One, yet his contribution to One for All's power is the greatest (only behind All Might), having held onto it for eighteen years before passing it to Daigoro Banjo. This not only granted it the extra power that would later allow All Might to defeat All for One, [[spoiler:it also let him and the other Torchbearers discover later on that One for All was a DeadlyUpgrade that would LifeDrain people with Quirks]].
* John Smith has two scenes in twenty-six episodes of ''Anime/MyHime''. He tells Natsuki her mother was planning to sell her to Searrs, which causes her PsychosomaticSuperpowerOutage, which leaves her vulnerable to Nao, which puts her in Shizuru's care, which causes [[DudeShesLikeInAComa Shizuru to give in to temptation and kiss Natsuki unawares]], which [[DatePeepers Haruka and Yukino witness]], which leads to [[PsychoLesbian Shizuru's breakdown]], which leads to the ''[[OneWomanArmy utter]]'' [[CurbstompBattle slaughter of District One]]. That was just the result of Smith's first scene. For his second, he tells [[BigBad The Obsidian Prince]] about the Vortex weapon that [[PosthumousCharacter Saeko Kuga]] developed for Miyu, causing Mikoto to get sicced on Midori, which results in her defeat and the death of her most important person.
* ''LightNovel/MyNextLifeAsAVillainessAllRoutesLeadToDoom'': Baron Shelley only shows up in flashbacks involving Anne, and nothing he ever does directly affects any members of the primary game cast, but him sending Anne to be with the Claes family after effectively disowning her was how she and Catarina become such close friends and she started breaking out of her submissive shell, and Catarina's efforts to stop him from marrying her off against her will is the major push that truly allowed Anne to break free of her mental shackles and decide to be her own person instead of what would potentially please other people.
* ''Manga/{{Naruto}}'':
** [[spoiler:Rin Nohara, as her death]] caused a major villain's StartOfDarkness, and by extension ''nearly every significant event in the plot.''
** [[spoiler:Sasuke]] in ''[[Anime/TheLastNarutoTheMovie The Last]]''. He may have been DemotedToExtra, but if he hadn't arrived in Konoha when he did with Hiashi in tow, then the Hokage Monument would have been reduced to dust, [[spoiler:Kakashi]] and countless others would have been killed and [[spoiler:the Raikage would have blown up the moon, killing Naruto and co]].
** Iruka, Naruto's teacher at the Academy, doesn't really have much to do with the series' action. But if it wasn't for his faith that Naruto was a good person and not the Kyuubi reborn, Naruto might well have turned out as AxCrazy as Gaara from the AllOfTheOtherReindeer treatment he recieved all his childhood. And it was because of Iruka's teaching and example that Naruto decided to try to [[spoiler:befriend the Kyuubi.]]
** Zabuza and Haku were the {{Starter Villain}}s of the series, appearing during the first proper story arc, when the manga's chapters were still in the low double digits, and dying only 15-20 chapters later. Yet, they still had a profound impact on Naruto and inspired him to create his own philosophy that rejected the concept of ninjas as tools, and instead emphasized their existence as human beings... Essentially, if it hadn't been for Zabuza and Haku, Naruto would never have become the MessianicArchetype he eventually turned into. This is much later acknowledged in-series by Kakashi who informs the [[BackFromTheDead resurrected Zabuza and Haku]] that Naruto found his own path in life thanks to them, and Kakashi himself expresses gratitude that they were Naruto's first opponents.
** Aoba Yamashiro is a minor Konoha jonin who blabs about Itachi's return to Konoha within earshot of Sasuke. Sasuke would run off for revenge, suffer a CurbStompBattle, and question the value of the village's training. Put simply, the Sasuke retrieval plot and ''the entire second half of the manga'' can be traced back to an otherwise inconsequential man carelessly running his mouth.
* Kaworu Nagisa from ''Anime/NeonGenesisEvangelion''. Despite only appearing in one episode, he serves major plot relevance as the final angel, has a prominent role in Shinji's development as a character, and has some of the most poignant scenes in the entire series.
* In ''Manga/OnePiece'':
** A minor Marine character named Shu who, despite appearing in only one episode of the anime, managed to actually destroy one of [[MasterSwordsman Zoro's]] swords thanks to his Rust-Rust Fruit powers. Not only did he rust up the sword that Zoro personally received from a man who respected him, but Zoro ends up using two swords for awhile until he finally gets a permanent replacement in the middle of the Thriller Bark arc.
** The unnamed mook of Caesar Clown who sent the distress signal [[spoiler: after being attacked by Kinemon]] to Luffy doesn't even ''appear'', but he indirectly manages to [[spoiler: bust Caesar Clown, remove Doflamingo from power by exposing his nefarious deeds, cause Law's defection from the Seven Warlords, save Zou and Wano from Kaido's people, set Luffy on the right path to Laugh Tale, make the World Government do away with the Seven Warlords System and start the Great Pirate War.]] Big impact indeed.
** Sora Vinsmoke is a minor character from the North Blue who's long dead by the time of the story and only interacts with one of the main characters. But her actions indirectly saved the Straw Hats several times over. [[spoiler: She's Sanji's mother, if she hadn't taken a dangerous drug to reverse the gene surgery on Sanji, he would have turned out like his brothers -- superpowerful, but completely lacking in empathy and would never have joined the Straw Hats.]]
** Captain Nezumi, a corrupt Marine only present for the Arlong arc, is the reason that Luffy received a bounty in the first place. Without him it may have taken longer to earn, if not just having been a far less eyecatching thirty-million at the start.
* Lady Matsu only appeared a couple times in ''Manga/{{Ooku}}: The Inner Chambers'', but her death is the catalyst for all the chaos of Tsunayoshi's latter reign, and by extension the rest of the Tokugawa shoguanate.
* Hibari and Hikari from ''Anime/{{Penguindrum}}''. For a long time, their only appearances were in the background on advertisements and in the ending credits, and then they showed up briefly in a backstory episode to give some insight into Himari's past. However, they end up being absolutely integral to the ending when they show up for less than five minutes in the final episode to drop off their new album, which holds Himari's favourite phrase and [[spoiler:the fate-transfer spell that allows her to live.]]
* Meowsie, a female Meowth that Team Rocket's was smitten by only appears in person in one episode of ''Anime/PokemonTheSeries'' (besides a handful of {{Imagine Spot}}s by the latter), though she is the entire reason that Meowth is sapient in the first place. Meowsie was unimpressed by a normal stray Meowth, so he learns to speak and act human to impress her. He didn't quite understand that Meowsie was a spoiled cat impressed by riches and spoils, and so she still only snubbed him. Heartbroken, Meowth then joined Team Rocket in hopes of achieving some street cred to impress her instead. Within the show's present day, Meowth met Meowsie again only once (in "Go West Young Meowth"), where it was revealed she was a stray and thus Meowth's talents could be useful to her needs.
* Lord Asano [[HeWhoMustNotBeSeen is never actually seen]] in ''Anime/PrincessMononoke'', but those are his samurai who are dangerously close to conquering Iron Town, and it may also have been his men that Ashitaka saw brutalizing the countryside before.
* Enrico, Massimo, and Federico of ''Manga/Reborn2004'' were the sons of the 9th and the previous Vongola members in line for the role of 10th, with Federico in particular being the favored son. Their influence amounted to little more than footnotes in the ''first'' chapter explaining how they died, and they've never been mentioned since. Had it not been for their untimely deaths, the family wouldn't have gone searching for the closest genetic link possible and ending up at wimpy Tsunayoshi's house, Tsuna wouldn't have learned about his family's ties to the Vongola, nobody would have gotten the strength to properly fight off the Kokuyo Gang, Xanxus might have gone through with his strong-arming and ruthless regime, the Millefiore family would definitely have wiped the Vongola out in 10 years, there wouldn't have been potential allies through the Simon family, the Arcobaleno curse would have remained on the tutors with no end in sight, and most importantly, they wouldn't have gotten the candidate [[spoiler:whose ideals and friends match the ''founding lineup'' of the Vongola itself and set the family on the path that led them back to its former glory.]]
* ''Anime/RevolutionaryGirlUtena'' has an example in Mrs. Ohtori, the mother of Akio's fiance Kanae and the wife to the actual chairman of the board at Ohtori Academy. She has less than a minute of screen time but every single thing about her ties into all the overall themes of the series. There's even a website which analyzes the symbolism within her first and only appearance, called [[http://ohtori.nu/mother/ Mother Dearest]].
* ''LightNovel/RollOverAndDie'': The black market slave merchant appeared in only the first two chapters of the light novel, but the impact he has is immense. If it wasn't for him, Jean would not have had the opportunity to sell Flum into slavery. This causes the Hero's party to start to break apart due to Flum being TheHeart of the party and Jean being short sighted. Additionally, this leads to Flum discovering the true nature of her affinity Reversal, and she also meets Milkit along with beginning her own Hero's journey.
* ''Manga/SaintSeiya'': Sagitta Ptolemy is just another Silver Saint who shows up for a few minutes and easily dies at the hands of Seiya. But not before he embeds one of his arrows in Saori/Athena's heart, giving her only 12 hours to live unless someone shines the light of her shield on her. It so happens that the shield is located at the top of the Sanctuary and Saori's Bronze Saints have to fight the phenomenally powerful Gold Saints to get to it. That's '''30-plus episodes''' of struggling that never would've happened had the mook Ptolemy not done what he did, as the Gold Saints would have just stood to attention if they had met Saori.
* ''LightNovel/SwordArtOnline'':
** Vassago Casals/[=PoH=]. He has very little screentime in Aincrad compared to Akihiko Kayaba but his actions have an impact that extends far beyond him. [[spoiler:Him establishing the PlayerKilling guild Laughing Coffin and corrupting many a player into becoming player killers and even real-life {{serial killer}}s is what directly causes the Phantom Bullet and Alicization arcs.]]
** Atsushi Kanamoto/Johnny Black. He's a minor but named member of Laughing Coffin, and later plays a small role in Phantom Bullet, [[spoiler:since the Shinkawa brothers needed an additional accomplice to carry out the murders on the day of [=BoB=].]] However, his real impact comes at the start of the Alicization arc, in which he [[spoiler:injects Kirito with his succhyoline, forcing him to be hooked up to the STL and essentially causing the storyline to happen.]]
* Ukina from ''Manga/TokyoGhoul''. Her existence heavily influences the plot of the series, though she only appears in a handful of flashbacks and little is known about her. [[spoiler:An undercover reporter that fell in love with a young Yoshimura, she gave birth to a HalfHumanHybrid while working on investigating '''V'''. When she was found out, his superiors forced Yoshimura to kill her as punishment... leading him to retire, and [[DaddyHadAGoodReasonForAbandoningYou hide]] their child elsewhere. Yoshimura took control of the 20th Ward, seeking to foster peace between humans and ghouls -- taking in Kaneki after his surgery. On the other hand, her journal drove [[BigBad Eto Yoshimura/Sen Takatsuki]] to seek revenge for her mother... first as the One-Eyed Owl, and later as the founder of Aogiri]].
* The evil alien prince Lacospo in ''Manga/ToLoveRu'' that hired Yami to assassinate Rito. He only has one episode in the anime, and even less of a presence in the manga, only appearing in a cameo or two, but without him Yami, and later Mea and Nemesis would never have come to Earth.
* ''Anime/YokaiWatchShadowsideTheReturnOfTheOniKing'': Azure Dragon and his Kindred Yo-kai only appear in the movie for a few seconds, but if they hadn't [[spoiler: destroyed Rasen's armor, the heroes wouldn't have been able to finish the job]].
* ''Franchise/YuGiOh'':
** Pegasus's wife Cyndia/Cecilia died young and her death served as a direct motivator for the Duelist Kingdom (as Pegasus wanted to take over Kaiba Corporation to use its technology to see and touch her again), as well as motivation for Pegasus to create the Duel Monsters game, thus indirectly contributing to the remaining arcs in the series and bringing about the other spinoffs.
** Mr Ishtar, Marik and Ishizu's father. He is long dead before Battle City but his abusive treatment of his family and obsession with protecting the Pharoah's tomb above his own family is what led to the creation of Dark Marik.
** The Rare Hunter doesn't even have a name and is in-universe considered a little more than a mook that Yugi effortlessly defeats but it was his defeat of Jonouchi/Joey that demonstrated how dangerous the Ghouls/Rare Hunters were and they have ''much'' better access to rare cards. He also serves to help kick off Jonouchi's arc by showing the gap between him and Yugi and sets Jonouchi off to improve himself. Also, because Yugi won back Jonouchi's Red Eyes Black Dragon from the Rare Hunter and Jonouchi refused to take it back until he became a worthy duelist, Yugi would be able to use the Red Eyes in his later duel to awaken the brainwashed Jonouchi.
* ''Anime/YuriOnIce'':
** The Nishigori triplets are relatively minor characters who tend to provide comic relief and exposition about how figure skating competitions work. However, they're also the ones responsible for kicking off the plot by recording Yuri's reenactment of famous figure skater Victor Nikiforov's program and uploading it online; the video soon [[InstantWebHit goes viral]], which catches Victor's attention and leads him to become Yuri's coach.
** Celestino, Yuri's former coach, is also a minor character, but if he hadn't dragged Yuri to a banquet that Yuri really didn't want to go to, [[spoiler:Yuri and Victor would never have met properly, and Victor wouldn't have already been interested in Yuri before seeing the viral video]], which ends up being important to the plot since [[spoiler:it's strongly implied that this was when Victor began to fall in love with Yuri, leading to them becoming an OfficialCouple]].

[[folder:Comic Books]]
* ''ComicBook/OneHundredBullets'':
** Arms dealer Abe Rothstein appears in precisely ''one'' issue of a 100-issue series (Issue #89), and he's killed at the end of that issue. In said issue, though, we learn that [[spoiler: he was the source of Agent Graves' attachés all along. His death signals the end of Graves' "game" with the leaders of the Trust.]]
** Joan D'Arcy is one of the less seen Trust heads and the last one to be formally introduced. However, her hiring of the man that kills Rothstein and [[spoiler: Javier Vasco]] is the lynchpin for the beginning of the end.
* ''ComicBook/AceOfSpace'': The Slogons only appear in the first issue, but are responsible for the whole plot due to killing the alien who held Ace's power-granting belt, thus leading to him acquiring it. The alien also fits, due to dying within the first couple pages of the first issue but empowering the hero.
* In ''ComicBook/{{Bamse}}'', ''two'' characters fit into this in Vargen's sad backstory. The first one is a lady, who recognizes the very young Vargen as the boy, who helped a gang of thieves with stealing her purse, so she calls the shop where Vargen works and gets him fired. And there is also the shop-keeper himself, who tells poor Vargen "once a thief, always a thief" before he fires him. None of these two characters had more than a few lines, but by refusing to give a young orphan a second chance, they were the ones who made Vargen become the most infamous criminal in the area, until Bamse was able to make him reform many years later.
* ''Franchise/{{Batman}}'' has Joseph Chilton aka Joe Chill, an average thug who once tried to rob a rich family in an alley, and ended up killing the two adults, but [[WouldntHurtAChild couldn't bring himself to shoot their young child]]. That family was the Waynes, and his parents' deaths were what motivated Bruce Wayne to create the 'Batman' identity to make sure that others wouldn't suffer like he had. Chill himself is small potatoes and tends to get unceremoniously killed off whenever the story is told, assuming an adaptation in which his actions aren't [[CompositeCharacter given to a more important character]] (e.g. in ''Film/Batman1989'' the Waynes' murderer is Jack Napier, who then becomes ComicBook/TheJoker), but had he not tried to mug the Waynes, Batman would never have existed.
* ''ComicBook/TheBlueStreak'': Scarface only appears in the first issue, but inspires the hero's superhero career by killing his brother.
* In ''ComicBook/{{Diabolik}}'' the Minister of Justice of Clerville rarely appears, [[LegacyCharacter no matter who holds the post]], but has two important roles:
** Just by existing in the background he makes sure that [[SympatheticInspectorAntagonist Ginko]] remains on Diabolik's case and is not replaced by lesser cops, as [[OvershadowedByAwesome Ginko is the only one who actually has a chance with Diabolik in spite of his many failures]].
** In Clerville no execution may happen without his authorization. Thus every time Diabolik ''is'' arrested, his continued survival depends by how fast the Minister and his staff can write down the death warranty and sign it, to the point that in occasions he expected to arrest Diabolik for sure Ginko has called the Minister beforehand to have him write down the warrant and reduce the time Eva has to break Diabolik out.
* ''ComicBook/{{Empowered}}'': Imperial Pimpotron Alpha graces all of six pages yet leaves two major legacies: Empowered's body image issues, and the [[ChekhovsGun Imperial Cosmichains]] that Emp later uses to subdue and seal a similarly sesquipedalian supervillain whose stay proves significantly more substantial -- Demonwolf.
* ComicBook/GreenArrow villain Veronica Dale, aka Hyrax, was a minor villain who appeared in a single story before dying, but in that single story she accomplished what no other villain had ever been able to do: she killed Oliver Queen. And he stayed dead for eight years, pretty impressive for a B-list hero.
* ''Franchise/JusticeLeagueOfAmerica'': ComicBook/MartianManhunter villain Commander Blanx appeared in a grand total of two JLA stories. In the first of those stories, however, he engineered the destruction of the entire Martian race, transforming J'onn J'onnz from the jovial crime fighter he was in UsefulNotes/{{the Silver Age|of Comic Books}} and into the introspective loner he is today.
* Franchise/MonsterVerse: [[Characters/MonsterVerseKaiju Camazotz]], who only appears in the ''Film/GodzillaVsKong'' prequel graphic novel ''Kingdom Kong'', has a pretty big impact on the bigger [=MonsterVerse=] overall, as he's directly responsible for [[NothingIsTheSameAnymore the destruction of Skull Island and all wild specimens of its local life]] via enclosing a PerpetualStorm over the island. This kicks off Kong and Team Kong's entire arc in the movie.
* ''ComicBook/PatPatriotAmericasJoanOfArc'': The foreman only appears for one eight-page issue, and doesn't even get a name, but he's responsible for Pat's superhero career by firing her, which led to her exposing his smuggling operation.
* The Green Goblin in ''ComicBook/ThePulse''. He's only in a few issues, but it was his final unmasking.
* ''ComicBook/ScoobyDooTeamUp'': The Great Gazoo. He shows up at the end of the crossover with ''WesternAnimation/TheFlintstones'' to send the meddling kids back to their own time but he mistakenly sends them to the Jetsons' time, allowing the next issue to happen.
* ''Franchise/SpiderMan'':
** The villain Belladonna appeared for all of one plotline, and wasn't much of a challenge for Spider-Man. The wall-crawler crossed paths with her when she tried to kill a CorruptCorporateExecutive who had ruined her business. The name of that executive? Roderick Kingsley, alias the Hobgoblin. Belladonna's attempts to murder Kinglsey left him determined to never be that vulnerable again, prompting him to look for ways to defend himself. The Hobgoblin went on to become one of Spider-Man's defining villains in the 1980s, in his prime ranking with the likes of ComicBook/NormanOsborn and ComicBook/DoctorOctopus.
** Emil Gregg, the compulsive confessor in [[ComicBook/{{Venom}} Eddie Brock's]] backstory. Gregg falsely confessed to Eddie that he was the serial killer known as the Sin Eater, a story Eddie published in his newspaper the Daily Globe. However, Spider-Man captured the real Sin Eater, exposing Gregg as a fraud and turning Eddie into a laughing stock. This resulted in Eddie's IrrationalHatred of Spider-Man which he tried to purge by going from church to church, praying for forgiveness. One of those churches turned out to be the place where Spider-Man had left the alien symbiote costume he had acquired in ''ComicBook/SecretWars1984'' and the rest is history.
** The unnamed crook who killed Uncle Ben only had one other appearance, and isn't even named in his first appearance, but if Peter had caught him instead of letting him go, Ben would never have died and Peter would never have become a hero.
* ''Franchise/StarWars: ComicBook/{{Legacy}}'' has ArcVillain Zenoc Quah, a treacherous Yuuzhan Vong Shaper. He only physically appears in a three-issue arc and is killed off at the end of it, but he sticks around just long enough for it to be revealed that it was he who sabotaged the Ossus Project and framed both his own race and the Jedi for it, kicking off the entire plot.
* ''ComicBook/TheSteelFist'': Ludlow only appears in the first issue, but he's responsible for the Steel Fist's existence, due to his mutilating the hand that ends up being empowered.
* ''Franchise/{{Superman}}'': Derek Marlowe was a minor crook who debuted in the ''ComicBook/StarfiresRevenge'' arc and was killed off one issue later, but ComicBook/{{Supergirl}} spent years dealing with malfunctioning powers because of the depowering pill he slipped into her drink during his single appearance.
* Bob from ''ComicBook/TheWalkingDead'' is only in two issues and initially seems to be around for a minor PetTheDog moment for The Governor. [[spoiler: His second appearance has him reveal his HiddenDepths as a former Army Medic and has him save The Governor's life after Michonne tortures him, allowing him to attack The Prison and kill half the cast.]]
* ''ComicBook/TheWraith'': Silky Weaver only appears for one half of one issue, but is responsible for the entire comic due to killing our hero, who rises from the grave to stop him.
* Dr. Bolivar Trask in ''ComicBook/XMen''. He appeared in exactly ''three'' issues before his death in a 1965 issue, but his creations -- the Sentinels -- regularly menace the X-Men to this day, and they serve as a potent symbol of anti-Mutant prejudice. Many of his surviving relatives are also major supporting characters in the ''X-Men'' mythos: his son Larry appeared in a notable Roy Thomas arc, his daughter Tanya (aka "Madame Sanctity") is the leader of the Sisterhood of the Askani, his brother Simon is a famous anti-Mutant activist, and his nephew Donald (himself an example of the trope) helped Cassandra Nova decimate the population of Genosha in ''ComicBook/NewXMen''.
* ''ComicBook/{{Yellowjacket}}'': Jake Mallon only shows up for the first issue, but he ends up kickstarting Vince Harley's superhero career by leaving him to be stung to death by bees, causing our hero to discover his control over them.

[[folder:Fan Works]]
* In ''Fanfic/FearNoEvil'', a ''Manga/MyHeroAcademia'' fanfic, Katsuki Bakugou only has an offscreen role until the last chapter. However, he sets off Izuku's kidnapping by Humarise by signing him up for the Humarise's mailing list.
* The ''Anime/ZombieLandSaga'' fanfiction, ''Fanfic/FranchouchouFeat'', has Koji Kaneda, who is established in a few chapters to be a StalkerWithACrush who wants Yugiri for himself under the delusion she reciprocates his feelings and wants leave Idol business. He loses it when Yugiri rejects him and, blaming Sakura for this, stabs the latter in the chest, only to get knocked out by Yugiri and Kotaro Tatsumi before he can discover Sakura's a zombie. Koji never appears again after this, but it was because of his attack on Sakura that [[IntrepidReporter Okaba]] discovers the members of Franchouchou are zombies, leading him to tell the girls' family and friends within Saga and allowing them to discover the girls' secret.
* ''Fanfic/AbraxasHrodvitnon'': In this ''Film/GodzillaKingOfTheMonsters2019'' fanfiction, [[Characters/AbraxasHrodvitnonHumans Madison Russell]] is somewhat DemotedToExtra compared to her roles in her Franchise/MonsterVerse appearances, but she's responsible for the human cast working out where the battle to rescue [[AdaptationalHeroism Monster X]] is going to take place. Without her, Monarch wouldn't have been present at the battle to stir [[AdaptationalHeroism Monster X]] and hasten its rebirth using the ''Argo''[='s=] Titan bio-acoustics speakers, and then the FinalBattle would've likely gone quite differently.
* ''Fanfic/HarryPotterAndTheMethodsOfRationality'':
** Bahry One-Hand. He is only present in half a dozen chapters, but his impact of the story is undeniable. If not for the scientific upbringing he gave to his son, Harry would be a completely different person and the story would look quite differently.
** Aunt Petunia. Her decision in this fic's timeline to marry a scientist instead of Vernon and her resolve to raise Harry as her own is one of the main divergence points from the canon storyline and the basis of the whole story. In spite of that major impact, Petunia doesn't appear all that often.
* ''Webcomic/HetaliaAxisPowers'' fanfic ''[[https://www.fanfiction.net/s/11886910/1/Gankona-Unnachgiebig-Unità Gankona, Unnachgiebig, Unità]]'': the homophobe and the bully appear in one chapter each and [[NoNameGiven weren't given actual names]]. However, their actions make Germany and Japan all the more protective and possessive over Italy in addition to heightening their [[GreenEyedMonster jealousy]] over each other, culminating in a ''massive'' CockFight which pushed [[spoiler:Italy to confess to both of them.]]
* In a ''Franchise/{{Digimon}}'' fan fiction ''Fanfic/Zero2ARevision'', Demon from the original timeline only appeared in one chapter explaining Shaun's backstory but it is ultimately his manipulations and genocide of the Digidestined that drove Shaun into trying to SetRightWhatOnceWentWrong, and subsequently starts the whole Zero 2 universe.
* A few characters in ''Fanfic/AngelOfTheBat'' appear to be this, but have actually had large roles, just off-camera. (Deacon Blackfire only appears in a flashback but did a lot to create the BigBad The Seraphim, [[spoiler: Joshua Lebowitz only has a few scenes but has spent years in defiance for The Seraphim]] etc.). But Jason Todd/ Red Hood's role in the story is simply acting as a hired killer for a few scenes. Despite this, defeating him helps bring closure to Stephanie's story arc and his knowledge of infiltrating The Seraphim's base is what leads to one of the two climaxes.
* In ''VideoGame/FinalFantasyVII'' fanfic ''Fanfic/TheFifthAct'', Yuffie is only present for a few scenes and is only there as the PluckyComicRelief. But she makes a huge impact as Cloud rescuing her gets him an audience with the Emperor of Wutai, her father. Her habit of stealing materia saves her father's life and forces Cloud to work a diplomatic solution when assassinating her father for his HonorBeforeReason stubborness was not a option. Cloud manages to convince Lord Kisaragi to surrender to Shin-Ra on his own terms which in turn attracts further attention from Shin-Ra. Further attention from Shin-Ra gets him recruited into the company in turn turn has major consequences in the latter half of the story.
** Young Cloud is only present for two chapters but he's privotal in getting [[PeggySue the elder Cloud's]] cover to fall part [[spoiler: and his rescue of Kunsel tells the rest of the cast where Cloud is being held.]]
** Vincent has very few scenes [[spoiler: but he turns the Turks against [[BigBad Hojo]] and is the one who kills him.]]
* ''WesternAnimation/TheLoudHouse'' fanfic ''Fanfic/RequiemForALoud'' has Adrien, a boy slightly older than Lincoln, who suffers from an advanced form of Leukemia. He only appears in chapter 5, but both this meeting and the letter he writes Lincoln later mark a turning point for Lincoln, and the story as a whole, since it causes Lincoln to accept his fate and try to make the most of the time he has left.
* In ''[[http://archiveofourown.org/series/454879 Birth of An Abomination]]'', the canon Ruby only appears in one scene [[spoiler:after she is shattered, so she doesn't even have ''lines'']], but it's because of her that another Ruby joins the Crystal Gems [[spoiler: and a third Ruby is motivated to get revenge on Sapphire and ''kills Greg'']], essentially starting the rest of the series.
* In ''[[https://www.fanfiction.net/s/2470299/1/True-Heroes-Year-One True Heroes]]'', Mighty Mom and Dyno Dad are never seen, and if the author had plans to reveal what happened (outside of a throwaway line where the Nega-Chin implies he killed them), the author quit writing before they came to fruition. It's there disappearance that leads to the Crimson Chin to take Timmy in as Cleft, which leads to the events of the series proper.
* The first WhamEpisode of ''Fanfic/PokemonResetBloodlines'' happened because of a guy named Tokiomi Borealis, who is only mentioned in passing to be a WealthyPhilanthropist who helped revive Gringy City and make it a nice place to live. [[spoiler: As it turns out, [[IHaveNoSon his disowning of his daughter Aurora]] [[FantasticRacism for being a bloodliner]] led the story's KnightOfCerebus Belladonna Tyrian to cross paths with Ash, and gave the revelation that our hero's look-alikes all over Kanto and abroad aren't pure coincidence.]]
* ''Fanfic/MrAndMrsGold'': Belle’s release from Regina’s torture (and all the ForWantOfANail) was done when [[spoiler:the Genie of the Mirror grew a consciouce and told Rumpel about it.]]
* Though only appearing in one chapter [[DirtyCoward Julian]] from ''Fanfic/MiraculousThePhoenixRises'' quickly earns his rank as the biggest HateSink of the entire fic. After Morgan overheard him giving a threatening call, she catches him in the act of attempting to kidnap a girl only to bungle her attempt at stopping him. [[MiscarriageOfJustice he then proceeds to have her framed for stalking and assault]], [[EvilIsPetty ruining her life]]. He makes no other appearences besides the opening flashback.
* In the ''WebAnimation/{{RWBY}}'' fic series ''Fanfic/TheMakingsOfTeamCRME'', Brigit Stark from ''Fanfic/MyNameIsCinder'' only shows up in two chapters of the whole story. However, she ends up being an ''insanely'' important character in retrospect. Brigit {{abusi|ve parents}}ng Cinder and killing her father is [[FreudianExcuse what drove Cinder to become a sociopath]].[[note]]Cinder's mental scarring comes up a lot throughout the stories.[[/note]] Cinder killing her left her on her own where she was picked up by bandits and [[GreaterScopeVillain Salem]] took interest in how damaged she was. In turn, Salem raised Cinder into becoming the power-hungry egomaniac she is in the show. Cinder assembling the team helped Emerald get off the streets and ended up being the reason Mercury is still alive. [[ForWantOfANail If Cinder weren't looking for Marcus when she did]], Mercury would've bled out and died shortly after killing him. And then, Cinder hired Roman to commit the Dust robberies, including [[ContinuityOverlap the one Ruby stopped in the pilot of the show]]. Had that robbery not gone on, Ozpin wouldn't have noticed Ruby's abilities and Ruby wouldn't have been accepted into Beacon early. Thus removing the catalyst for the whole show in the first place! Basically (as far as the ''CRME''-verse is concerned), [[ForWantOfANail without the actions of Brigit Stark]], '''''RWBY'' would have never happened'''.
* ''Fanfic/AManOfIron'' has Renly Baratheon. He's very much on the periphery in Book 1, but Book 2 reveals that [[spoiler: he was responsible for Tony's kidnapping by those bandits. Which makes him indirectly responsible for the existence of Iron Man, who emboldened other mystics and metahumans to make themselves known.]]
* Mrs Horaki has very little in the way of characterization and only appears in a few scenes of ''Fanfic/AdviceAndTrust'', [[spoiler:but she was single handedly responsible for keeping Kaworu from crossing the DespairEventHorizon and causing TheEndOfTheWorldAsWeKnowIt after Rei's HeroicSacrifice.]]
* [[spoiler:Shiji and Asuka's daughter Aki]] is only physically present for two chapters in ''Fanfic/TheSecondTry'' (technically four, but they only show up in two of them at the very end), yet they shaped the entire course of the story since [[spoiler:[[ChildrenRaiseYou she formed the bulk of Asuka and Shinji's Character Development]], was the entire reason for Kaworu sending them back in time in the first place, and was the one who convinced Rei not to initiate Third Impact.]]
* A group of Japanese wizards in training in ''[[https://www.fanfiction.net/s/13157026/1/Eternal-Fantasy Eternal Fantasy]]'' set up a spell to make their favorite RPG come to life inside the building they're playing in. One of them accidentally inverted part of the boundary field, marking the building's interior as the ''outside'' of the field, and causing the entirety of Earth to fuse with the videogame.
* ''Fanfic/MastermindStrategistForHire'': A forum poster going by [=Whyher0es301=] appears in only the first two chapters of the fic: his use of the plan Izuku gave him to murder Mt. Lady and get away with it, along with him telling his friends about Izuku's account, [=M4sterM1nd404=], plants the seeds for Izuku becoming the villain Mastermind.
* Tazuna's presence in ''Fanfic/SonOfTheSannin'' is almost completely glossed over due to the events of the Wave mission not being handled by Naruto's team and taking place offscreen, yet his actions directly lead to Mei Terumi seeking Konoha's help in the Kirigakure civil war (and by extention, the formation of the Konoha/Suna/Kiri alliance) [[spoiler:due to [[{{Irony}} Zabuza]] being the one assigned to protect him as part of his parole]].
* ''Fanfic/InfinityTrainBlossomingTrail'':
** Chloe's classmate Akemi becomes an UnwittingInstigatorOfDoom when she discusses the Alola League with her at lunch. This leads to [[InternalReveal Chloe learning]] that Ash is the Alola Champion, and several other classmates who overhear this harass her into challenging him, setting off a cascade of events that push Chloe past her RageBreakingPoint and culminate in her boarding the Train.
** Leon innocently telling his little brother Hop about Ash potentially being the one to fight him causes Hop -- reeling from Bede's BreakingSpeech -- to fall into a HeroicBSOD that causes the Infinity Train to take him away.
* Essentially applies to Peter and Wanda in the Franchise/MarvelCinematicUniverse fic "[[https://archiveofourown.org/works/37160386/ What If... Wanda Didn't Mourn Alone?]]", which sees Peter joining Wanda when she goes to Westview and Wanda later joining Peter in New York as Strange casts the spell. While neither can stop the larger-scale threat, culminating in Wanda's memory of Peter being erased just like the rest of the world, [[spoiler:during a demon-induced breakdown Wanda regains her memory of Peter and is inspired to stop her current actions before going on to meet with him. After the two reunite, Wanda helps Peter get back in touch with the other Avengers, who help him gain confidence to properly rebuild his life; Kate Bishop even uses her position at Bishop Securities to give Peter a job in the company's R&D department, giving him a job that lets him use his full potential and an employer who doesn't mind if he has to leave during the day for his superhero activities]].
* Another example involving Peter and Wanda features in "[[https://archiveofourown.org/works/38856951/ A Real Chance]]", which opens with Uatu visiting He Who Remains, which reveals that the TVA has pruned 137 different timelines where someone reached out to Wanda before or after Westview to offer her an alternative source of support than the Darkhold and her obsession with her children. Witnessing the final divergence where Wanda meets Peter Parker in London after [[Film/SpiderManFarFromHome the battle on London Bridge]], Uatu discreetly gives Wanda a brief moment of insight into those other possibilities, giving her sufficient advance notice to force the TVA to leave Peter alone and thus let this timeline continue, allowing her to prevent Peter's identity being exposed after she destroys the Darkhold.
* In "[[https://www.fanfiction.net/s/13132829/1/Star-Wars-Arda-Unleashed Star Wars: Arda Unleashed]]"- part of a series where Anakin Skywalker and Obi-Wan Kenobi joined [[Film/TheLordOfTheRings the War of the Ring]] during [[WesternAnimation/StarWarsTheCloneWars the Clone Wars]]- this comparatively applies to the role the residents of Arda have on the Clone Wars. While the campaign on Arda only lasted a few months and involved one isolated, primitive world, the friends and allies Anakin and Obi-Wan made there [[spoiler:lead to Anakin rejecting any thought that he might turn to the Dark Side, even as Palpatine learns some of Sauron's tricks to increase his own power]].
* ''Fanfic/InfinityTrainKnightOfTheOrangeLily''
** Margaret from the Pearl Gates Car, had a son named Dar. [[spoiler:He was killed off by the Apex with a sledgehammer.]] Gladion learning about this fact has him decide to stop the Apex before they cause aymore trouble, setting off the plot of the story.
** Utahoshi shows off in a flashback, but his kindness towards Tokio, closeness to Kisaragi [[spoiler:and his subsequent death by Grace's knife]], plays a big part in the two factions named Solitaire and White Gestalt.
** Lampetia gets a few scenes that explain who she is, her relationship to Larkspur and that she's Specter's denizen partner. [[spoiler:Her death -- a request from her to London -- will end up shaping Specter's personal arc.]]
* The ''Series/{{Friends}}'' fic "[[https://www.fanfiction.net/s/13574811/1/The-One-Where-Heckles-Has-An-Existential-Crisis The One Where Heckles Has An Existential Crisis]]" reveals that the gang's downstairs neighbour in the first season, Mr Heckles, was actually Chandler's future self from a timeline where Chandler's commitment issues eventually ended his relationship with Monica as she got back together with Richard. As a result of Heckles arranging for the gang to get all his personal possessions after his death (taking out everything that identifies him specifically as Chandler's future self), he creates the canon timeline where Chandler marries Monica and the gang all stay closer friends, where it's implied that Heckles' timeline saw Rachel move to Paris, the rest of the gang all move away from Chandler, and [[ArsonMurderAndJaywalking Ross lost Marcel for good when he ran out of the apartment while Rachel was looking after him]].
* ''[[https://www.fanfiction.net/s/13725975/1/A-Carnal-Mistake A Carnal Mistake]]'': Two events at once that affected [[Anime/CodeGeass Lelouch]]. First was C.C. remove ''all'' Geass commands from Lelouch, with the intent of removing the Geass he put on himself for fighting Mao and make him able to use Geass again. The second was a Sex-Ed at Ashford, which leads to a discussion about sex history among the student council. This leads Lelouch to recall seeing his parents having sex, which he couldn't remember before because his father used ''his'' Geass to erase that memory. It now means Lelouch knows his father's power.
* The ''[[WesternAnimation/TheOctonauts Octonauts]]'' fanfiction ''Fanfic/JuniorOfficers'' has Zulimar Zebra. She was only mentioned once in "[[Recap/JuniorOfficersS1E22TheUnderseaTwister The Undersea Twister]]", but her quitting the team years ago was the first of several events that led to Barnacles becoming captain.
* ''Fanfic/TellingLiesNoMama'': Aurore and Mirelle only make [[TheCameo a brief appearance]] in the first chapter, which isn’t even at the school where 90% of the story takes place. However, they are the ones who set the story in motion. When they overhear that Lila’s mother at the bakery, saying who she is related to, they get excited and show her the interviews of Lila on the Ladyblog lying her butt off about saving a rockstar’s cat and being besties with Ladybug, unwittingly exposing her lies to her mother. With that revealed, Madame Rossi goes digging and finds out that the school had ''not'' been closed like her daughter said, and storms over there to confront Lila and confirm to her classmates that she is a liar.
* ''Fanfic/TheWeaverOption'':
** The Last Ultramarine appears for only the final part of the first scene in the story, but in that brief appearance he disrupts Tzeentch's ritual. This ensures that Taylor [[spoiler:and the other parahumans]] arrive in the 35th Millennium free from Chaos, setting in motion the plot.
** Nostradomus Vandire has only a handful of appearances during which he is easily deposed by Taylor and sent to an abrupt death in a Penal Legion. However, his death infuriates his father, Xerxes Vandire, who uses his position to turn the Adeptus Administratum against Taylor.
** Vyrion Kaeran does little beyond picking a fight with Taylor and getting himself killed. His death infruiates his home craftworld, whose quest to gain revenge on the Mon-Keigh who dared to kill an Eldar Farseer turns Biel-Tan into one of her more persistent enemies. This also means Vyrion is indirectly responsible for [[spoiler:Biel-Tan's destruction for interfering with the Mark of Commorragh]].
* ''Fanfic/WithConfidence'' has Amida Nakamura, who doesn't appear past the first chapter, but whose interaction with Izuku ends up being the nail which causes the fic to diverge significantly from canon.
* ''Fanfic/CodePrime'':
** Makeshift only appears in one chapter of ''R1'', where his role is posing as Wheeljack to infiltrate the Autobots and Black Knights, and being killed to keep the location of the Ark a secret. However, [[spoiler:Megatron uses his remains to create a Pretender in Euphemia's image in order to kick off the Special Administrative Zone Massacre. This leads to Suzaku and Dreadwing defecting to the Autobots and Black Knights. And the massacre results in the Black Rebellion, which serves as a distraction that allows the Decepticons to attack Pendragon and take over Britannia.]]
** Joseph Fenette, Shirley's father, is possibly a major example. Unlike in canon, he survives the rockslide at Narita, [[spoiler:but is captured by Shockwave and Soundwave, along with the other scientists from Code-R, and is presumed dead.]] This leads to a long chain of events:
*** His supposed death causes Lelouch several problems with Shirley, which leads to Shirley [[spoiler:finding out about Lelouch being Zero and choosing to join the Autobots and Black Knights.]]
*** [[spoiler:His capture along with Code-R reveals the project, and Geass, to Megatron, making the Decepticon leader suspect Charles of treachery, and that Charles' brother Victor/V.V. is not dead as he previously thought.]]
*** Lelouch’s aforementioned problems with Shirley caused by Joseph’s capture lead to Mao making his move, forming an alliance with Megatron to capture C.C. [[spoiler:This ends with Mao being subjected to Shockwave’s experiments to learn more on Geass after Mao fails Megatron one too many times.]]
*** [[spoiler:Megatron captures V.V. and learns about the Ragnarok Connection, and Shockwave’s experiments on Geass lead to Megatron gaining his Dark Geass of Absolute Terror.]]
*** Eventually, [[spoiler:this all leads to the Decepticons deciding to overthrow Britannia at the end of ''R1'', with the Decepticons taking over the Geass Order and declaring themselves the new rulers of Earth.]]
* In ''[[https://www.fanfiction.net/s/12765261/1/Fidget-You-Are-a-Mystery Fidget, You Are a Mystery]]'', the witch only appears briefly in the first and fourth chapters (and is killed off in her second appearance), but it's only because of her (or rather, her potions) that Milo's soul ended up in [[WesternAnimation/GadgetAndTheGadgetinis Fidget's]] body.
* In ''Fanfic/ThisBites'', Nero is an unremarkable member of [=CP9=] that is unceremoniously pushed off of the Puffing Tom by Boss. However, his presence meant that the organization had [[spoiler:''three'' Devil Fruits in reserve instead of just the two that Kaku and Kalifa ate in canon]]. This leads to [[spoiler:Cross finding the spare Devil Fruit in Spandam's office, which turns out to be the Human-Human Fruit: Model Child that Merry eats to avoid dying like in canon]].
* In the ''WesternAnimation/{{Aladdin}}'' fanfic ''[[https://www.fanfiction.net/s/6238727/1/Opposites-Destroy Opposites Destroy]]'', Nada only appears in the first chapter and the end of the last chapter, but it's only because she rubbed the necklace containing [[JerkassGenie Djinn]] that the evil genie was freed.
* ''Fanfic/GuardiansWizardsAndKungFuFighters'': A minor background character, who shows up in a single flashback and isn't even named, ends up shaping a lot of the backstory. [[spoiler: One of Julian's men convinces him to destroy Carhaiz, which leads to Julian being captured, Caleb having the responsibility of leading the Rebellion forced onto him, and laying the groundwork for Tristan becoming a servant of Phobos.]]

[[folder:Film — Animation]]
* {{Meta}}-example in Howard Ashman. The only [[WesternAnimation/TheLittleMermaid1989 two]] [[WesternAnimation/BeautyAndTheBeast films]] he completed [[note]](he began working on ''Aladdin'', but Music/AlanMenken finished the film with Creator/TimRice after Howard's death)[[/note]] both won the Academy Award for Best Song Score (as it was then known) and the UsefulNotes/AcademyAwardForBestOriginalSong, became critically-acclaimed and highly successful, and eventually conferred with "classic" status from both fans and Disney.
* If it weren't for Gru's nosy neighbor Jillian setting him up on a terrible blind date in ''WesternAnimation/DespicableMe2'', Gru would not have realized that he has feelings for Lucy.
* The Franchise/DisneyAnimatedCanon:
** Rafiki in ''WesternAnimation/TheLionKing1994'' and especially in the [[WesternAnimation/TheLionKing2019 2019 remake]]. For the first two-thirds of the film he's seen mostly sticking to himself with the occasional chuckle and saying of Simba's name. In the penultimate act, upon realizing Simba is alive, he finds him to deliver the lesson that just running away from his past and his problems may help at avoiding pain, but only by returning and confronting them can he actually move past it.
** ''WesternAnimation/SleepingBeauty'' took a creative twist by making the good fairies the main characters instead of the titular princess; as such, Aurora herself only has eighteen lines in a movie whose entire plot revolves around her.
** The anonymous sentry on the Great Wall in ''WesternAnimation/{{Mulan}}''. Facing down Shan Yu, he defiantly lights the signal beacon on his tower that alerts the others that they're under attack. Without that, it might have taken a lot longer for the army to realize the Huns had invaded.
** Susan Hegarty the rescue lady in ''WesternAnimation/LiloAndStitch''. She was the person who oversaw Lilo's legal adoption of Stitch. The rest of the film and its franchise would have turned out very differently if she denied the adoption.
** ''WesternAnimation/{{Frozen|2013}}''
*** Anna and Elsa's parents are only alive for the first 15 minutes. Yet their isolation of the sisters causes the entire plot of the movie.
*** The Trolls. They have just as much screen time as the parents, yet they contribute just as equally. Specifically the scene where Grand Pabbie alters Anna's memory -- giving her amnesia and forgetting Elsa's ice magic -- is what results in her completely unaware why her sister is constantly avoiding her and why she won't come home with her when they reunite.
** King Runeard from ''WesternAnimation/FrozenII'' only appear in a flashback during AMinorKidroduction along with a recreation during Elsa's ice figure representation but it's his attempt at oppresing the citizens of Northuldra that not only led to the cursed mist blocking it but also what led to Elsa getting her ice powers in the first place as an indirect consequence of his actions.
** Emmitt Otterton from ''WesternAnimation/{{Zootopia}}'' only appears a few times and doesn't even say a single word onscreen (Only Mrs. Otterton does all the talking), but it's his disappearance that causes Judy to become involved in the investigation that drives much of the story, and he's also inadvertently the cause of her meeting Nick to begin with.
* "ComicBook/GreenArrow" in "ComicBook/BatmanTheDarkKnightReturns" shows up very late into the comic book (and animated adaptation), but shoots a Kryptonite-tipped arrow which is central to weakening Superman before the end of his fight with Batman.
* The plot of most of the ''WesternAnimation/IceAge'' films is usually kicked off by [[ButtMonkey Scrat]]'s acorn-related antics, which often indirectly affect the story.
* The fisherman in ''WesternAnimation/TheIronGiant'' only appears in the first few scenes of the film, but it's these scenes that set the plot in motion. After crashing into the eponymous Giant in a storm, he tells the government and some friends at a diner about his encounter. While no one seems to believe his story, it's enough to lead agent Kent Mansley and curious child Hogarth Hughes, respectively, to investigate the strange happenings in Rockwell and discover the true nature of the "invader from Mars".
* In the [[WesternAnimation/KungFuPanda Kung Fu Panda trilogy]], the unnamed parents of Lord Shen only appear during one brief flashback at the beginning of ''WesternAnimation/KungFuPanda2''. However, had they not asked the Soothsayer to predict their son's future, the events of the trilogy would have been very different. Indeed, because of this prophecy, Shen tried to [[spoiler: exterminate all pandas]], which ultimately resulted in Po being found and adopted by Mr. Ping and growing up near the Jade Palace, becoming the Dragon Warrior years later. Had Shen's parents not asked for this prophecy, Po may have still lived with his parents in their village far from the Jade Palace and never have become the Dragon Warrior.
* In ''WesternAnimation/MarvelRisingSecretWarriors'', [[spoiler: Captain America]] only appears for a minute at the end of the movie, but he indirectly helped form the team.
* ''WesternAnimation/MyLittlePonyTheMovie2017'' would have been really short if it weren't for Derpy shoving Twilight out of the way of Tempest Shadow's petrification grenade early on, saving Equestria by giving Twilight a chance to escape.
* Creator/{{Pixar}}:
** For the first three films in the ''Franchise/ToyStory'' film series: Andy. He doesn't do much as a character, but the main characters' entire lives and motivations revolve around him. Meanwhile, the Little Green Aliens becomes this in ''WesternAnimation/ToyStory3'', [[spoiler:upon rescuing the toys from the incinerator]].
*** Andy's Mother also accidentally kickstarts the events of the first three films: In the first, she buys Buzz Lightyear for Andy's birthday. In the second, she grabs Wheezy off the self and into the yard sale box and in the third, she throws out the toys who were inside the trash bag thinking they were trash and it also gives them the belief that Andy doesn't want them for much of the film.
** ''WesternAnimation/FindingNemo'' has [[TheDreaded the Barracuda]]. Throughout the entire film, he appears exactly once: in the opening scene, where he kills Marlin's wife, Coral, and all of their babies save one. This directly creates Marlin's FatalFlaw: he becomes an OverprotectiveDad to said surviving baby, Nemo, whose attempt at rebelling years later causes him to be captured by Dr. Sherman, starting Marlin's frantic search and the film's main plot. Said search, by the way, also brings Marlin and Dory together, thus without the Barracuda, the events of ''WesternAnimation/FindingDory'' wouldn't happen, either.
*** Coral herself also counts, as her death led to Marlin's overprotectiveness of Nemo, which started the main plot.
** ''WesternAnimation/TheIncredibles'' has three.
*** Edna Mode. She appears three times, all in the first half of the film. She's the one who alerts Helen to her husband's moonlighting hero work, and convinces Helen to go track Bob down.
*** Bomb Voyage. He's the one who throws the bomb onto Buddy, which causes the train crash, which helps lead to the SuperRegistrationAct, and [[spoiler:is part of Buddy's impetus for turning into Syndrome.]]
*** And probably the biggest of the three, Oliver Sansweet. This man only has two scenes, but his attempted suicide and lawsuit against Mr. Incredible once he stops him and injures him in the process open the floodgates for the lawsuits that become the reason for the Registration Act. Better yet, when Mr. Incredible attempts to stop his suicide, he tackles Sansweet into the bank that is being robbed by... Bomb Voyage.
** ''WesternAnimation/{{Cars}}'' has the four tuners -- Boost, DJ, Wingo, and Snot Rod -- who decide to mess with Mack after he has trouble staying awake. Had they chosen not to bother him, Lightning would not have fallen out of him and wound up in Radiator Springs. They do later show up in a post credits scene where they get arrested by Sheriff for speeding and continue to appear in other media around the movie, so this is downplayed.
** ''WesternAnimation/{{Ratatouille}}'' has Solene [=LeClaire=], the food critic who inadvertently tries Remy's soup. She only appears in one scene where she says one word and never interacts with Remy or Linguini, but her rave review of Remy's soup convinces Skinner not to fire Linguini and kickstarts Remy and Linguini's friendship.
** Ellie in ''WesternAnimation/{{Up}}'', whose death is responsible for Carl's attitude for most of the film, and the construction worker [[AllThereInTheManual Steve]] whose being (accidentally) assaulted by Carl caused Carl to be committed to Shady Oaks Retirement Community, which was the triggering event that caused Carl to float his house to Paradise Falls.
** "Frightening" Frank [=McCay=] in ''WesternAnimation/MonstersUniversity'' only shows up in the beginning of the film but he is the one who encouraged Mike to become a scarer in the first place, thus setting off the plot of this film and [[WesternAnimation/MonstersInc the previous one]].
** ''WesternAnimation/TheGoodDinosaur'': Forrest Woodbrush briefly shows up to try to adopt Spot and that's what prompts Arlo to name the "critter".
** Mama WesternAnimation/{{Coco}} gets somewhere around 5-10 minutes of screentime, [[SecondaryCharacterTitle yet there's a reason she's the title character]], and not Miguel or Hector. Her memories of her late father is the only thing keeping Hector alive in the Spirit World, since nobody else cares about him. Without her, Hector would have suffered the Final Death before the movie even started, and nobody would ever know the truth about him and Ernesto.
* The homeless man in ''WesternAnimation/SouthParkBiggerLongerAndUncut'' is responsible for taking Stan, Kyle, Cartman and Kenny into the R rated movie they wanted to see. Them swearing in class leads to their parents led by Sheila to declare war on Canada.
* The Green Goblin in ''WesternAnimation/SpiderManIntoTheSpiderVerse'' is demoted from his usual BigBad status, instead being portrayed as [[TheBrute one of the Kingpin's lackeys.]] However, he's the one who [[spoiler:beats down the Peter Parker of Miles' universe enough that Kingpin can finish him off]], which pushes Miles into becoming Spider-Man, and shoving Parker into [[DoomsdayDevice Kingpin's supercollider]] is what drags all the other Spiders into Miles' universe, kick-starting the rest of the plot.

[[folder:Literature]]
* ''Literature/TheAshesSeries'': Carl Adams, a right-wing fanatic who even the main characters view as a madman, engineers the nuclear war that causes TheEndOfTheWorldAsWeKnowIt and the subsequent rise of new governments such as Ben's secessionist movement, kicking off a forty book series. However, [[DiscOneFinalBoss Adams is killed in the fifth chapter of the first book, making way for more (mostly liberal) antagonists.]]
* ''Literature/BazilBroketail'': Smilgax, in more ways than one. He is the one who cuts off the tip of Bazil's tail, causing the need to regrow it via magic and earning the hero his titular nickname. Also, because he is outed as a traitor and a part of assassination scheme, it forces Thrembode to change plans and abduct Princess Besita instead — basically setting up the plot for the entire second half of the novel.
* ''Literature/TheColdMoons'': Tendril appears in only one chapter, the second chapter, and it's heavily implied that she died off-screen. However, without her, the DecoyProtagonist Bamber would have died and, with him, all the other badgers would have likely perished as well.
* ''Literature/TheCrocodileGod's'' main antagonist is one of Mirasol's Spanish employers in the newly-colonized Philippines, and the story only refers to him as [[CaptainObvious Mirasol's master]] or [[RaceNameBasis "the Spaniard."]] His major action is [[ImperiledInPregnancy to shoot the heavily-pregnant Mirasol]] so [[RevengeByProxy her husband Haik shuts up]] about [[PhysicalGod being the Tagalog tribe's sea-god.]] This means he has committed [[KillTheGod Deicide]] by [[TragicStillbirth killing their unborn daughter,]] clinched the DeathOfTheOldGods in the Philippines after [[EverybodysDeadDave Haik has long assumed the rest of the pantheon is dead,]] and sent their ReincarnationRomance into a spiral of [[TraumaCongaLine trauma and separation.]]
* ''Literature/{{Dracula}}'': Dracula himself. He actually only appears "on screen" in a handful of scenes, but he dominates practically everything that happens in the book.
* Arianna Ortega in ''Literature/TheDresdenFiles'' interacts only with Harry, and appears in a grand total of three chapters before biting it. Her plans result in Harry damning his soul forever, and sets the plots for book 12 and 13 in motion.
** The minor Red Court Vampire "Bianca St. Claire" only appears in Books 1 & 3. However her falling out and subsequent attempts at [[EvilIsPetty petty revenge]] against Harry both start off the war with the White Council and eventually [[spoiler: gives Harry the opportunity to wipe out her entire species. Whoops?]]
** He Who Walks Behind. He is a powerful demon knight on the levels of being a PhysicalGod. As of book 14 ''Cold Days'', he was only in a single chapter flashback in book 13 ''Ghost Story.'' Besides that, he was referenced maybe five times in the entire series. But his actions in Harry's past, [[spoiler:the brutal murder of a gas station attendant Harry tried robbing]] drove him to avenge the little guy and develop the ChronicHeroSyndrome that would make Harry face down forces that no mortal had tried challenging before.
* Clarisse [=McClellan=] from ''Literature/Fahrenheit451'' [[NeverFoundTheBody is obscurely written out of the story]] ''very'' early on; however, her influence on Guy Montag instigates the entire plot and every event that happens therein. (Some adaptations even write her back in later.)
* In the ''Literature/FearStreet'' spin-off series ''Fear Street Seniors'', the first actual senior to die was Danielle Cortez. She only appears in a few pages and doesn't even receive the courtesy of a yearbook entry until the sixth volume, which is three books after her death, but the fact remains that she dies on the very first day of the new school year, which sets the mood for the rest of the school year. Her death is the harbinger for the rest of the seniors who die throughout the year.
* ''Literature/TheGreatGreeneHeist'': Keith's cousin Naomi is never mentioned again after the fourth chapter (out of forty-four), but her unopposed run for student council threatens to give Keith and Wilton a tiebreaker vote if they win their own bids.
* The StoryWithinAStory in ''Literature/HansBrinkerOrTheSilverSkates'' about a boy plugging a dike with his finger and preventing a flood is more famous than the actual story of Hans Brinker and his skates.
* ''Literature/HarryPotter'':
** Lily Evans really doesn't show up a lot, but her actions drove the entire characterization of [[spoiler:Snape]], and her HeroicSacrifice set up the entire plot.
** The eponymous [[Literature/HarryPotterAndTheGobletOfFire Goblet of Fire]] only gets a couple of appearances early on the book and then is (almost) never mentioned again. It, however, kickstarts the book's main plot.
** Narcissa Malfoy in the latter ''Literature/HarryPotter'' books. In terms of facetime and notoriety, she takes backseat to her husband and son and is mostly just another snobby wizard supremacist. However, in [[Literature/HarryPotterAndTheHalfBloodPrince the sixth book]], her binding Snape to the Unbreakable vow is ultimately responsible for the climax of the story. And in book 7, her willingness to [[MamaBear lie to]] [[BigBad Voldemort]] about Harry's death is what gives Harry the chance to win the war once and for all.
** Lucius Malfoy’s role in the story also by far eclipses his actual screen time. Dumbledore had suspected all along that Voldemort had made horcruxes at some point but didn’t: have any proof, know how many there could be, know what kind of objects they’d be, and have a time frame. When Lucius slips Ginny the diary horcrux in [[Literature/HarryPotterAndTheChamberOfSecrets second book]], he puts into motion the events of the rest of the series. Dumbledore was able to work backwards and figure out everything he didn’t know (that he’d made them in his young adult years, they were objects based around the Hogwarts founders, and since he’s not deaf that there were more) to ultimately take him down. When Ginny uses the diary to open the Chamber of Secrets, it also let them get basilisk venom which is one of the few things that can destroy horcuxes.
** Kreacher. When screenwriter Michael Goldenberg tried to [[AdaptedOut adapt him out]], Creator/JKRowling told him that doing so would put a SpannerInTheWorks of the seventh film. (Goldenberg can be forgiven for attempting it, since Kreacher's ''one'' plot-critical moment had, at the time, not yet been published.)
** The sixth book introduces many characters who appear only via PensieveFlashback, most -- if not all -- of whom are also [[PosthumousCharacter long gone by the time the series start]]: Marvolo, Morfin, and Merope Gaunt; Bob Ogden; [[spoiler: Tom Riddle, Sr.]]; Mrs. Cole; and Hepzibah Smith and her House Elf, Hokey. [[spoiler: They're all connected to Voldemort's backstory: Marvolo, Morfin, Merope, and Riddle Sr. are Voldemort's maternal grandfather, uncle, mother, and father, respectively; Ogden's encounter with them eventually led to Voldemort's birth at the orphanage Mrs. Cole would be running by the time Dumbledore went there, and Voldemort met Hepzibah Smith and Hokey when he was employed to liaise with Hepzibah for her antique collections, two of which eventually fell into Voldemort's hands.]]
** Dumbledore's siblings, Aberforth and Ariana, don't show up until very late in the series (Aberforth is mentioned in passing a few times and shows up about three quarters through ''Deathly Hallows'' but Ariana goes completely unmentioned until the beginning of that book) but are very important to his backstory and the story in general. To make a long story short, some Muggle boys did something horrible to Ariana when they saw her doing magic when she was a kid. It's implied but not outright stated to have been some sort of sexual abuse and their dad went to prison for attacking them in {{Revenge}}. The trauma caused Ariana to repress her magic and become unstable. She accidentally killed their mom. Dumbledore got a PromotionToParent and didn't take it well because he wanted to go see the world but he wanted Aberforth to finish school and so he stayed. Gellert Grindelwald came knocking on their village and Albus wanted to go on his trip with him to TakeOverTheWorld and take Ariana with them. Aberforth put his foot down and a MeleeATrois ensued with poor Ariana caught in the middle, she got killed even though they don't know who actually killed her. Her death made Albus realize that power went to his head and explains why the greatest wizard of his age became a teacher instead of an EvilOverlord. He still hates himself for it, so much that the only time he ever actually mentions her is in ''Film/FantasticBeastsTheCrimesOfGrindelwald'' while trying to empathize with [[spoiler: Leta Lestrange]] who similarly still hates herself for incidentally causing her younger sibling’s death as a kid. Aberforth also feels incredibly guilty for it and it's why the brothers aren't necessarily close as adults. She's been dead for about a hundred years by the time of his death but wanting to see her to apologize to her in the Resurrection Stone is how he gets the curse that kills him. It's also clear on a re-read that Aberforth uses his role as the barkeeper at the Hog's Head to spy on Death Eaters for his brother. In fact, he's the one who kicked Snape out of the bar halfway through the prophecy, setting in motion the event that cause Harry's parents' death and in turn Snape turning spy against Voldemort.
* An unnamed Medusan native who wandered into the human enclave on the planet and ended up dead due to a drug overdose was responsible for much of the ''Literature/HonorHarrington'' series. It was his possession of a firearm that shouldn't have been possible for the native population to develop on their own and ravings about a religious leader that alerted the Manticorans something serious was going on. The resulting series of events secured Harrington a promotion and the notice of her superiors, which put her into position for more critical events that the junior captain of an old destroyer wouldn't have been.
* Primrose "Prim" Everdeen from ''Literature/TheHungerGames'' in the first book. She isn't present for most of the plot, but it's because of her that Katniss ends up in the Games in the first place.
** And by extension, Katniss's role in those Games were what ended up sparking the rebellion.
* The ghost of James Incandenza in ''Literature/InfiniteJest'' doesn't even have any lines, but single-handedly sets almost the whole novel's plot into motion [[spoiler: which culminates in the apocalypse.]]
* ''Literature/TheLastDaysOfKrypton'': Tyr-Us and Gil-Ex's four allies on the reformed Kryptonian Council have no names, little BackStory, and only three lines of dialogue between them, but their existence gives the troublemakers on the Council a majority vote, [[spoiler:directly leading to Krypton's destruction.]]
* In ''Literature/LookingForAlaska'', the title character has a boyfriend, a college student named Jake, who is repeatedly referred to throughout the book but actually seen a grand total of once. Nevertheless, his influence is felt throughout the story, his existence being the reason Alaska and protagonist Miles never act on their feelings for each other, causing no shortage of angst for him (and, it's implied, her as well). And then, just when you've probably forgotten him, a phone call from him at exactly the wrong time about exactly the wrong subject [[UnwittingInstigatorOfDoom causes something very, very bad to happen]].
* ''Literature/TheLordOfTheRings'' books are full of this. You have characters like Erkenbrand, a Marshall of Rohan leading the troops that Gandalf collects to save everyone at Helm's Deep, or Ghan-buri-Ghan, a NobleSavage tribesman who leads the Rohirrim around an ambush so they can arrive at the Battle of the Pelennor Fields in time and at full strength.
** Also occurs in ''Literature/TheHobbit'' with characters like Bard, and elsewhere as well -- Tolkien was obviously very fond of the idea that ''everyone,'' not just the protagonists or the most powerful beings, can have a major influence on the world.
* ''Literature/TheMalteseFalcon'': General Kemidov is TheGhost, but even before the story begins, when Gutman wanted to buy the McGuffin, he realized that it would be important and replaced it with a MockGuffin that the gang found very easy to steal, making him the ''real'' MagnificentBastard of the story.
* ''Literature/TheScholomance:'' Clarita is only mentioned once, in passing, before the last fifth of the first book, but plays a significant role in the climax.
* Watson's friend Stamford has about two lines, doesn't make it past the first chapter of ''A Study in Scarlet'', and is promptly [[ChuckCunninghamSyndrome never seen again]]. But he introduced [[TheWatson John Watson]] and [[GreatDetective Sherlock Holmes]] to each other, resulting in their forming a [[HeterosexualLifePartners life-long]] [[HoYay friendship]], and kicking off one of the most well-known and enjoyable [[Literature/SherlockHolmes mystery series]] of modern literature.
** Professor James Moriarty is only in ''two'' works in the entire Literature/SherlockHolmes canon (the short story "The Final Problem" and the novel ''Literature/TheValleyOfFear''), and he is almost entirely [[TheGhost behind the scenes]] in both, with no dialogue in either work, and no explicit appearances aside from one brief scene where Holmes points him out to Watson on a train. Nevertheless, he is the only character in the {{canon}} who Holmes ever called his intellectual equal, and he was the catalyst behind Holmes' infamous [[FakingTheDead three-year disappearance]] -- which was [[{{Retcon}} originally meant to be]] his ''death''. For good reason, many adaptations [[AscendedExtra significantly increase his presence]], making his role as Holmes' archenemy much more explicit.
** Likewise, Irene Adler only ever appears in one story, "A Scandal in Bohemia". She outwits the Great Detective and escapes scot-free, and [[WorthyOpponent an admiring Holmes refers to her as "the woman" ever afterwards]]. Many modern adaptations have her stick around and [[PromotedToLoveInterest promote her to love interest]] (somewhat ignoring the fact that Holmes was the best man at her wedding).
* Hannibal Lecter from ''Literature/TheSilenceOfTheLambs''. He's a minor character in the novel (and in the film he's on screen for only fifteen minutes or so), and yet he drives the plot forward on several occasions all by himself. (Amusingly, Anthony Hopkins set a record by winning the Best Actor Oscar in the shortest amount of screen time.)
** This is even more the case in the preceding novel, ''Red Dragon.'' Unlike his relationship with Clarice, which formed the real meat of ''Silence of the Lambs'', his relationship with Will Graham is mostly restricted to a mutual hatred. He appears on a total of seven pages, and new scenes had to be written for him in the Edward Norton adaptation to justify his billing. His actions continue impact the story long after his final appearance, however.
* ''Literature/ASongOfIceAndFire'':
** Balon Greyjoy is one of the eponymous monarchs in the War of the Five Kings. He barely has any time interacting with the POV characters, and appears in only small parts of two chapters in the second book, and doesn't reappear before dying off screen in the third. However, his decision in the second book to go to war with the North rather than joining them effectively ends the chances of ''that'' king to win their war.
** Mirri Maz Duur only appeared in four chapters (three episodes) of ''Literature/AGameOfThrones'', including the one where she is killed. The only POV character she interacts with is Daenerys. However, her actions become not only the driving force behind much of Daenerys's story arc, but also the reason that dragons (and in turn, stronger magic), have returned to the world. ([[spoiler:Given that said dragons are expected to defend the Wall against the Others, Mirri Maz Duur might end up having a greater hand in saving Westeros than anyone ''besides'' Daenerys.]])
** Lord Walder Frey appears in only ''three'' chapters of the series (or episodes of the show). He is still able to orchestrate a WhamEpisode in which he helps win the war for his side by killing off several important characters.
** Lysa Arryn has very little pagetime, but while SayingTooMuch in her last chapter she reveals that she is directly responsible for the events that lead to the War of the Five Kings (murdering Jon Arryn, causing Robert to ask Ned to be his Hand; implying the Lannisters as his murderer to Catelyn causing her to eventually take Tyrion captive and anger Tywin Lannister).
** Lyanna Stark only appears as a statue and in the memories of Ned Stark, but she had one of the largest influences in the plot: her kidnapping led to the death of Ned's father and brother and Robert's Rebellion, her death turned Robert Baratheon into a depressed man whose disdain for ruling caused no short end to problems [[spoiler:and she might be mother to Jon Snow, a character whose role in the books has been incredibly important.]]
* ''Literature/StarWarsKenobi'': Being set on Tatooine just after ''Film/RevengeOfTheSith'', Anakin's role is limited to allusions and mentions in Obi-Wan's meditations, but he has a great deal of importance in the story's events. Aside from being the reason Obi-Wan is on Tatooine in the first place, [[spoiler:his massacre of the Tusken clan in ''Film/AttackOfTheClones'' is responsible for both A'Yark's clan's dire straits and the decrease in demand for the Settler's Call that drives Orrin to fabricate Tusken attacks.]]
* ''Literature/WarriorCats'':
** Sasha in ''Literature/WarriorCatsTheNewProphecy''. Although she only appears once or twice, she mothered [[spoiler: the villain's children, who go on to become super important characters.]]
** Socks and Ruby in the [[OELManga manga]] ''The Rise of Scourge''. Both were mean to Tiny, causing him to run away and become [[MadeOfEvil Scourge]]. Also Tigerclaw, but [[BigBad only in the manga.]]
* In the present-day ''Literature/TheWheelOfTime'', [[MadScientist Aginor]] is one of the least appearing, least accomplished members of [[QuirkyMinibossSquad the Forsaken]] ([[spoiler: he dies ''twice'' without accomplishing much that's noteworthy]]). In the ''backstory'', on the other hand, he [[EvilutionaryBiologist created]] the [[AlwaysChaoticEvil Shadowspawn races]], meaning he was responsible for most of the {{mooks}} the heroes fight ''and'' for untold suffering caused by his "children" over the millennia.

[[folder:Live-Action TV]]
* ''Series/TwentyFour'':
** Even people who haven't seen the show are likely aware of the cultural phenomenon that is Mandy (aka "Naked Mandy"), the cold, ruthless [[TheChessmaster chessmaster]] assassin who routinely evaded capture only to make a sudden, shocking, bombastic return when the heroes least expected her. Fans of the show, however, know that she only ever appeared in seven episodes, almost never for more than one scene, and she only ever made two "shocking returns" (and it was never a surprise for any of the heroes -- none of them met her or knew who she was until her last arc in Season 4 -- only for the audience). Still, she did make ''quite'' a splash whenever she did show up, most notably in the Season 2 finale, where in her one minute of screentime she managed to single-handedly turn the upbeat, triumphant ending into a horribly uncertain DownerEnding.
** There's also Conrad Haas who only appears in one episode (the Season 5 premier), but he made a tremendous (and shocking) impact on the season/show as a whole by [[spoiler:[[ProfessionalKiller assassinating]] [[HeroKiller former president David Palmer]]]].
** Mitch Anderson is a minor villain in Season 4 whose appearances can be counted on one hand. But by the final time he appears he ends up shooting Air Force One and putting the current President out of commission... causing the series' [[BreakoutVillain iconic villain]] [[PresidentEvil Charles Logan]] to get sworn in his stead. Logan winds up causing trouble for rest of the show, even if at times it's indirectly for arcs where he's absent, and all of it can be traced back to what Anderson did.
* ''{{Series/Arrow}}'' had this with Justin Claybourne, and in a Season 5 flashback, too. He was a CorruptCorporateExecutive who The Hood killed after his company went around making poor people sick. However, [[spoiler: his death led to his illegitimate son swearing revenge. He was trained by Talia Al Ghul, and went on to become Prometheus, arguably the biggest villain on the show to date.]]
* ''Series/BandOfBrothers'' shows Moose Heyliger being shot in a case of UnfriendlyFire by an unnamed sentry. The man in real life was quickly transferred to another regiment for his own safety and does not appear in the series again. Nonetheless this results in the incompetent Norman Dike being put in charge of Easy Company through the Battle of the Bulge. Many men lost their lives (or limbs) due to the man's poor leadership skills.
* Before ''{{Series/Batman|1966}}'' the Riddler had all of two appearances in the comics, neither in over a decade. Frank Gorshin's performance single-handedly [[RescuedFromTheScrappyHeap saved the character]] from obscurity, the Riddler himself is considered a core villain in Batman lore, with most adaptations drawing heavily on Gorshin's version of the character.
* ''Series/BetterCallSaul'': Jimmy's father appears for less than 5 minutes in a flashback, but Jimmy's whole corruption into Saul and the animosity between the [=McGill=] brothers can be traced to him being StupidGood towards conmen and Jimmy losing respect for him and swiping cash from his registers.
* ''Series/BreakingBad'':
** Christian "Combo" Ortega is one of Heisenberg's flunkies and also his first casualty; he has so little screen time that Walter's not even sure which one he is when notified of his death. However, Combo has two major effects on the series; Firstly, his death led to a bloody chain of events that would consume the Heisenberg empire. Secondly, it's later revealed that he, not Jesse, procured the RV that proved so crucial to Walter's operation.
** The rival dealers have 2-3 appearances, have no lines and are killed off in their last appearance. But [[spoiler: they kill Combo and later Tomas, whose deaths Jesse attempts to avenge, but Walt kills them, leading to the downfalls of Gus's syndicate as well as Walt's, later on.]]
** Brock Cantillo. He may be a little kid with very few appearances, but [[spoiler:when Jesse found out Walter poisoned him back in Season 4, he permanently cuts ties with Walter and becomes a significant threat]].
** Dr. Delcavoli. He's only used as exposition for Walt's cancer, barely being seen for the first two seasons. However, his treatment helped Walt's cancer enter remission; it may have altered Walt's attempts to break bad in the meth business since he assumed that he would die and leave his family a sizable amount of cash before going in too deep.
** Drew Sharp, a child who appears for literally less than a minute, completely changes the entire show upon [[spoiler:his murder at Todd's hands]], as this single moment is the reason why [[spoiler:Jesse and Mike want out of Walt's empire for good, setting up the rest of the conflict for Season 5A]].
* ''Series/BuffyTheVampireSlayer'': Olaf the Trollgod, the former husband of Anya Jenkins, is this on two levels. Firstly, as revealed in season 7, Olaf was the first person Anya ever cursed which led to her being recruited as a vengeance demon. Secondly, Olaf's [[DropTheHammer divine hammer]] proves instrumental in defeating Glory, the main villain of season 5.
* ''Series/DancingOnTheEdge'': Jessie Taylor (Creator/AngelCoulby), whose role is to sing and get murdered, but remains one of the most memorable aspects of the miniseries.
* ''Series/DoctorWho'':
** Gordon Tipple's incarnation of the Master in ''The TV Movie'' appears for mere seconds, and what few lines he had were cut in the official release of the episode, but his ThanatosGambit sets the whole plot running (and indirectly causes the Seventh Doctor's regeneration into the Eighth).
** Harriet Jones, Prime Minister (yes, [[RunningGag we know who she is]]), played by Creator/PenelopeWilton, appears in a grand total of four episodes. In the [[Recap/DoctorWho2005CSTheChristmasInvasion third]] of those, the Doctor's reaction to something she does changes the entire course of history and has serious consequences for the next three seasons of that show and all of ''Series/{{Torchwood}}''. Then, despite having been thoroughly screwed over by said Doctor, she proceeds to help save the world with a [[TearJerker tear-jerking]] HeroicSacrifice. She's also a [[OneSceneWonder Four-Episode Wonder]], as she's one of the most iconic supporting characters of the new series and a fan favourite.
** [[Recap/DoctorWhoS30E2TheFiresOfPompeii "The Fires of Pompeii"]]: Caecilius and his family only appear in this one episode, but they have a big enough impact on the Doctor that he subconsciously models an incarnation on the man's face over a thousand years later.
** Cass, in the "[[Recap/DoctorWho50thPrequelTheNightOfTheDoctor Night of the Doctor]]" minisode. She appears in ''Doctor Who'' for all of six minutes, [[spoiler:most of which is after her death. But her death is what pushes the Doctor over the DespairEventHorizon and into participating in the Time War, which had a HUGE impact on the rest of the series.]]
* ''Series/{{Friends}}'' has Mr. Waltham, Rachel's boss in Season 4. He's only in two episodes, but in his second and last appearance, he asks Rachel to give his niece a tour of America as she's visiting. His niece? Emily, who becomes an important character in Ross's life with their relationship and subsequent failed marriage, which hangs over Ross for the rest of the series.
* ''Series/GameOfThrones'':
** Lyanna had one of the largest influences in the plot: her kidnapping led to the death of Ned's father and brother and Robert's Rebellion, her death turned Robert Baratheon into a depressed man whose disdain for ruling caused no short end to problems and casts a constant shadow in his marriage to Cersei. And most of all, she is mother to Jon Snow, an incredibly important character.
** Wyman Manderly shows up for about one short scene at the end of the sixth season, but after Lady Mormont declared her endorsement of Jon Snow as King in The North, his agreement is what catalyzes the motion.
** Martyn and Willem Lannister are two small, sacrificial characters. Their murders lead to Robb losing the support of House Karstark, to an apparently renewed alliance with House Frey and to the Red Wedding.
* Rory Flanagan from ''Series/{{Glee}}'' only had a few episodes in the spotlight, and was relegated to the background for most of Season 3 before disappearing afterwards. However his brief infatuation with Brittany led to Santana becoming more defensive of her, which further exacerbated the rift between her and the rest of the glee club, ultimately leading not only to the formation of the Troubletones but Santana being outed by Finn.
* Doug Forcett from ''Series/TheGoodPlace''. [[spoiler: After Michael meets Doug to find out what makes a good person and finds how horribly broken he has become trying to be good, Shawn's gloating that even Doug will end up in the Bad Place even with his admirable 520,000 points encourages the gang to go further and find out just how horribly broken the points system is and to strive for the necessary changes, due to which Doug earns his spot in the Good Place.]]
* In ''{{Series/Gotham}}'', [[TheSociopath Jerome]] only shows up in a few episodes, dies in the third episode of Season 2, and also [[spoiler:causes enough chaos that watching a video recording of his antics causes people across Gotham to snap, thus making Jerome, in all likelihood, the inspiration for [[ComicBook/TheJoker a certain clown]].]]
* From ''Series/{{Hannibal}}'':
** Garrett Jacob Hobbes, the serial killer known as the Minnesota Shrike. He appears as the primary antagonist of the first episode, and his crime spree is stopped by the end of the episode when he is shot to death by protagonist Will Graham. However, the guilt Will feels over killing Hobbes, combined with the guilt Hobbes' daughter Abigail feels for having an indirect hand in her father's murders, contributes a great deal to both Will and Abigail's storylines in Season 1. The incident also sets up the ArcSymbol of the raven-feathered stag, and foreshadows the climax of Season 2.
** Neal Frank. He's a PosthumousCharacter whose death is a major part of Dr. Bedelia du Maurier's story arc and was established to have been a patient who died under her care and led her to retire from active practice. [[spoiler:The flashback episode reveals that Hannibal was his actual therapist that he was seeing for insomnia. Instead, Hannibal hypnotized him into choking when he gets upset, and he was actually nothing more than another innocent victim caught in Hannibal's games. Bedelia was even going to prescribe the same therapy he was getting from Hannibal when he complains to her about his treatment. When he calls her out on it and starts to choke, she shoved his tongue down his throat instead of saving him. In other words, she lied about his death, which throws all of her previous characterization for a loop and implies she's actually no different from Hannibal when she's talking to Will Graham.]]
* ''Series/{{House}}'': While not as important as his [[Literature/SherlockHolmes name]] would suggest, the appearance of Jack Moriarty, the man who shot House, had repercussions beyond his brief appearance. He appeared in only one episode, and almost all his scenes took place in House's head, but his shooting House led to House's ketamine treatment, which led to him temporarily being able to walk pain-free.
* In ''Series/HowIMetYourMother'', the Mother's FirstLove Max isn't even seen on-screen but [[spoiler: his death was enough for the Mother to swear off dating and be unable to move on in any relationship.]]
* ''Series/KamenRiderZiO'' is a crossover series involving time travel and meeting the characters from previous ''Kamen Rider'' shows. Of these, the role with the biggest impact is that of Kamen Rider Gaim, one of the few other Riders capable of time travel, who in his few minutes of screentime sets off a butterfly effect ultimately leading to the show breaking out of the StableTimeLoop the main cast had unknowingly been perpetuating.
* ''Series/LetsMakeADeal'' began as a game show where contestants were picked out of the audience at random. Then one day a lady came on holding a sign that read "Roses are red, violets are blue, why can't I make a deal with you?" in the hopes that host Monty Hall would pick her - and he did. That one woman ignited one of the show's most enduring aspects, which was people dressing in wacky costumes or holding flashy signs in order to get chosen.
* In ''Series/{{Lost}}'', Jacob never appeared onscreen until the end of the fifth season... in an episode in which he was killed at the end. In the next season, he appeared just a handful of times as a ghost or in flashbacks. Nevertheless, he is one of the major characters in the MythArc of the series.
* On the fourth season finale of ''Series/MadamSecretary'', a colonel is served divorce papers by his wife when she finds him with another woman. At work, the colonel is the highest ranking officer when the radar shows a massive Russian nuclear launch on the U.S. The President orders a counterstrike but the colonel can't enter the codes as his security clearance has been revoked because of the divorce. This delays the launch long enough for a general to arrive and reveal the "attack" is all a simulation. Lampshaded by the Chief of Staff.
-->'''Russell''': So the world is saved thanks to a philandering general. Maybe the mistress should get a medal.
* ''Series/Merlin2008'':
** Phil Davis appeared in a guest spot that lasts no more than five minutes. In that time he ''mortally wounds'' [[spoiler:King Uther]], a major character who had been on the show since the beginning, and changes the entire course of the show.
** Kara, Mordred's GirlOfTheWeek whose execution at Arthur's behest starts the DisasterDominoes that leads directly to Mordred's FaceHeelTurn and the GrandFinale.
* In ''Series/{{NCIS}}'', Ari Haswari first appeared two-thirds of the way through the first season, and wasn't actually named until his second appearance in the season finale. He dies in his ''fifth'' appearance, in the second episode of Season 3. Over his five appearances, he crippled Ducky's first assistant, causing Jimmy (who is still on the cast as of Season 19) to replace him, killed Kate, causing Ziva (who stayed on the show until the beginning of Season 11) to replace her on the team, and people Ari had connections with keep running into Team Gibbs and impacting their lives (such as Ari's half-brother showing up and murdering Gibbs' second ex-wife Diane), even though he's been dead for over a decade now.
* ''Series/OnceUponATime'':
** Zelena's birth father appears in only one episode, simply as a palace gardener disguising as a prince. He seduces Cora and gets her pregnant, but does not appear again except asking for a bribe. Because of the illegitimate pregnancy, Cora abandons Zelena in the forest -- which leads to her getting taken to Oz and becoming the Wicked Witch of the West.
** Dorothy Gale likewise only appears in one episode. All she does is arrive from Kansas and mistakenly throw the water on Zelena. However she acts as a FaceHeelDoorSlam and Zelena turns down her redemption and sets out on her path to villainy.
** The Duke of Weselton courts Princess Helga and then makes a pass at her older sister Ingrid. In trying to save her sister from an attack, Ingrid accidentally kills Helga and is sealed in an urn by her other sister Gerda.
** Isla only appears in one episode, [[spoiler:but is the reason why the Land Without Magic is what it is.]]
* Mrs Inglis, the HR manager who fires Victor Meldrew in the first episode of ''Series/OneFootInTheGrave'', thereby setting up the rest of the series. Played by Susie Blake -- quite a big name cameo -- she even gets the opening line of the entire series but her role is over within the first ten minutes.
* In the opening scene of ''Series/OrphanBlack'', Sarah Manning sees a woman who looks exactly like her, Beth Childs, at a train station. [[spoiler:Then Beth throws herself in front of a train and Sarah steals her identity, kicking off a series of events that soon leads to the revelation that they are clones, the whole premise of the show. Although Sarah spends most of the first season pretending to be Beth, she has only properly appeared since the opening scene in a video and a brief dream sequence. Her death plays a major role in the arcs of Paul Dierden and Art Bell, and her presence is very much felt even well into the third season.]]
* Johnny Post from ''Series/{{Oz}}'' dies in the second episode, but his murder of Dino Ortaloni kicks off the conflict over who gets to control the drug trade, kickstarting the series.
* ''Franchise/PowerRangers'':
** ''Series/MightyMorphinPowerRangers'': The astronauts who [[UnwittingInstigatorOfDoom unwittingly]] released [[BigBad Rita Repulsa]] [[SealedEvilInACan from her prison]]. They are never seen nor mentioned again and we don't even learn their names, yet their mistake had massive consequences for Earth that would be felt for years.
*** Season 3 has the gymnastics coach, Gunter Schmidt who only appears for three episodes yet plays a factor in Kimberly's decision to leave for the Pan-Olympic Games and pick Kat as her successor.
** ''Film/MightyMorphinPowerRangersTheMovie'': Mirroring the situation above, we have the construction workers who uncover the egg Ivan Ooze was trapped in by Zordon.
** ''Series/PowerRangersTurbo'': Goldgoyle was a MonsterOfTheWeek who in his single appearance destroyed all of the Rangers' zords. This was only the beginning of the heroes' DarkestHour.
*** In turn, this leads to a positive example of this trope, and probably the biggest in this franchise since the case with Rita. General Norquist, the base commander of NASADA, with only minor appearances between two episodes of this season and three of the next, has no reason to believe a kid who looks like he came from a war zone that the Power Rangers need their super-advanced space shuttle. And yet, [[SomethingOnlyTheyWouldSay upon hearing the name of the planet Eltar]] (that he somehow knows and, given his reaction, knows the importance of), he drops everything to have the shuttle launch immediately with four equally beat-up looking teenagers, who he also has no reason to believe are the Rangers, and a robot onboard. But with this one act, Norquist unwittingly causes [[Series/PowerRangersInSpace a chain of events that result in the salvation of the entire universe from the greater evil about to befall it]]. And arguably, even the means for more Rangers to rise to save the day in the years to come.
** ''Series/PowerRangersLostGalaxy'': Psycho Pink appeared in only two episodes in the season (though she and the other PsychoRangers were major villains in the [[Series/PowerRangersInSpace previous season]]) yet she was pivotal in one of the most memorable moments in not only ''Lost Galaxy'' but the Power Rangers franchise as a whole: the death of the Galaxy Pink Ranger Kendrix Morgan.
*** From the same season, we have the old lady from the first episode whom Leo saves from a mugging. Her words that the new world would need people like him is what spurs Leo to stowaway unto the shuttle and leads to the events of him becoming the Red Ranger.
** ''Series/PowerRangersLightspeedRescue'': The nameless nomads who open the tomb containing the demons allowing them to return to menace Mariner Bay. Humans bringing doom is a common theme in Power Rangers.
** ''Series/PowerRangersTimeForce'': Venomark was a MonsterOfTheWeek whose connection to the BigBad Ransik ended up playing a role in the creation of another major villain Frax. Venomark bit Ransik and the venom of his bite resulted in Ransik's condition of his mutation causing him pain. Dr Ferricks saved Ransik by providing him with a special serum only for Ransik to turn on him and nearly kill him. Ferricks survives and transforms himself into the robot Frax. In the present, Frax unleashes Venomark to distract Ransik while he destroys Ransik's entire serum supply and finally makes his own move for world domination.
** ''Series/PowerRangersWildForce'': Onikage only appeared in two episodes, but his presence resulted in major events for the remaining few episodes. Heralding in the return of Master Org, his appearance led to Princess Shayla being kidnapped, the deaths of Mandilok and Toxica, Jindrax defecting from the Orgs, and set the stage for Master's Org's end game in the series finale.
** ''Series/PowerRangersRPM'': Prior to the present events of the show, Alphabet Soup was a corrupt government facility which kidnapped young children and forced them to create secret military projects. One of their victims was Doctor K who in an attempt to escape the facility created the Venjix virus but was captured before she could activate the firewall to stop it from spreading to the rest of the world. Or, as we later find out in 11 real world years, [[spoiler: [[Series/PowerRangersBeastMorphers other universes, namely the main one]].]]
* ''Series/RedDwarf'': Lister's cat Frankenstein only appeared in two episodes. Of those, she only appears for a scene in each one (one of those appearences was in an alternate universe too). However, it is Lister being caught with the cat and being put into stasis as a result that kickstarts the series. Frankenstein also becomes the ancestor of an entire race of cat like humanoids, one of which (The Cat) is a regular cast member.
* Throughout the first season of ''Series/TheResident'', Olive Tan is a "frequent flyer" hypochondriac who keeps showing up and complaining of illnesses she doesn't have. In her last visit, she thinks she might have be connected to her cancer. Used to her antics, Devon calmly tells her she doesn't have cancer. Tan protests that she does and furthermore [[spoiler: has been receiving chemotherapy from Dr. Lane Hunter. This leads to the discovery that Hunter has been pulling a massive fraud by giving perfectly healthy patients fake cancer diagnoses and chemotherapy just to get rich on the insurance payments and make herself look like a "miracle" healer. Tan's lack of any cancer symptoms is the evidence needed to bust her.]]
* ''Series/TheSopranos'' has Dr. Bruce Cusamano, Tony's doctor. He only appears in a supporting role in a paltry handful of episodes, but he kicks off the plot of ''the entire series'' by referring Tony to a psychiatrist after his panic attack, leading to him going to Dr. Melfi for therapy in the first episode. In fact, one of the very first lines of the series (before he's actually appeared) is ''about'' him.
-->'''Dr. Melfi:''' My understanding from Dr. Cusamano, your family physician, is that you had a panic attack.
* Major (later Lieutenant Colonel) Samuels from ''Series/StargateSG1''. Despite only appearing in four episodes, he's the one who approaches Jack O'Neill in the pilot, brings him back to the SGC, and basically starts O'Neill's many years of serving in the Stargate Program.
** Jolinar dies in her introductory episode, but her connection with Carter has a much larger impact on the plot due to both the introduction of the Tok'ra and the aftereffects of possession.
* ''Franchise/StarTrek''
** John Colicos played Kor, the first ever Klingon, only once on ''Series/StarTrekTheOriginalSeries'' before reprising the role decades later on ''Series/StarTrekDeepSpaceNine'', yet his Genghis Khan-influenced performance set the standard for all Klingons throughout the whole franchise.
** In ''Series/StarTrekDeepSpaceNine'' Morn is little more than a recurring extra that hangs out at the bar and never speaks. The turning point in the war that took up the series' main arc was his smuggling crucial information inside a present for his mother.
* Pilar has only a couple of scenes in the first episode of ''Series/{{Velvet}}''. However, her refusal to guarantee that the workers would keep their jobs if she paid off Velvet's debts [[StarCrossedLovers ensures the course of Ana and Alberto's true love run anything but smooth]]. [[spoiler:Her actions take on a more deliberately villainous light after her Season 3 arc.]]
** Don Rafael is dead by the end of Episode 1. However, his actions in this episode and the {{Backstory}} planted the seeds for almost every major conflict in the series.
* Judah Botwin is [[PosthumousCharacter dead before]] ''{{Series/Weeds}}'' [[PosthumousCharacter even begins]], and he only appears twice, briefly, in video footage taken before his death. However, it quickly becomes clear that he had a very stabilizing influence on his family, who almost immediately begin acting out once he's gone. His wife, with no idea how to provide for the family in his absence, turns to dealing marijuana, and his sons begin exhibiting sociopathic behavior, particularly Shane, for whom Judah was one of the only people who truly understood him and encouraged him to be himself, and area in which his mother is clearly out of her depth.
* Throughout its fifteen-year run, barely an episode of ''{{Series/Supernatural}}'' went by without reference to John Winchester, the father of the main characters whose disappearance kicked off the show's initial plot. It can be shocking to learn, therefore, that he only appears in 17 out of 327 episodes (and four of those were relatively minor flashbacks to his youth, during which he wasn't even portrayed by his main actor Creator/JeffreyDeanMorgan).
* ''Series/YoungSheldon'':
** Libby is only in one episode, but is the main catalyst to Sheldon's contempt for geology which he'd carry with him to adulthood.
** Marcus is in four episodes and has zero lines, but [[spoiler:Missy's breakup with him in the Season 4 finale causes the entire Cooper family to get into an argument, setting the stage for George possibly having an affair and the family breaking up.]] More will be revealed in Season 5.

[[folder:Manhua]]
* Xiao Meng like most of the Handicapped Warriors/Crippled Legion in ''Manhua/RavagesOfTime'' has a small role relative to [[Literature/RomanceOfTheThreeKingdoms the canon cast]], ''the'' major chain of events in ''Ravages'' begins with Xiao Meng [[HeroicSacrifice sacrificing himself]] (non-fatally) during a mission: The group's leader Liaoyuan Huo [[HeroicBSOD was so distraught by this as to leave the Handicapped Warriors]] and [[MurderInc go freelance]], with one of his contracts being an assassination attempt against Cao Cao[[note]]in which Xiao Meng also participated independently[[/note]], the thwarting of which was immediately followed by a retaliatory purge of the Sima clan[[note]]Cao Cao's bodyguard recognized Xiao Meng as being beautiful but not Lady Zou... and while the Sima clan didn't order the hit, they ''were'' committing an anti-Cao mutiny meant to coincide with the assassination attempt[[/note]], spurring both Sima Yi's revenge-motivated political ambition and Xiao Meng's participation in Lu Bu's war with Cao Cao[[note]]and thus Xiao Meng [[MoeGreeneSpecial shooting out Xiaohou Dun's left eye]][[/note]], the former of which coalesced into [[TheStarscream Sima Yi's long-term plan]] and the latter of which culminates in one final assassination attempt against Cao Cao, the failure of which endangered Sima Yi's climb to the top so [[YouHaveOutlivedYourUsefulness he sold out Xiao Meng to lynching]]... which both led to Huo's ''wrecking'' Yuan Tan's army while searching for Meng's corpse[[note]]or rather, Meng's ''bones''[[/note]], permanently damaging Tan's standing in the Yuan clan[[note]]thanks to Yuan Fang opportunistically -- there's no indication that he had a direct hand in the incident -- having the news spread[[/note]], and to the split between Huo and Yi that led to [[BecomingTheMask Huo permanently taking up his cover identity]]: [[NamesToRunAwayFromReallyFast Zhao Yun]].
** Assuming that the dream that opens the first chapter and is referenced multiple times after is actually the canon ending of ''Ravages'', then the chain of events begun with Xiao Meng's self-sacrifice ends with [[spoiler:Zhao Yun killing Sima Yi ''over fifty years'' after Meng's death]].
* In ''Manhua/MyWifeIsADemonQueen'', the Demon Tribe's High Priest only appears in the first chapter, and is killed off before Chapter 4. Yet, if it hadn't been for her, Xiang Ye would never have been summoned to serve as Isabella's champion, and Isabella would have been captured and likely executed by the Regent.

[[folder:Myths & Religion]]
* Eris in Myth/ClassicalMythology's Trojan War cycle. All the other gods were invited to a wedding, but as [[ChaosIsEvil the goddess of chaos]], she was excluded. She responded by sneaking up to the reception and throwing in a golden apple that read "[[FairestOfThemAll For the Fairest]]." Three goddesses fought over it, and chose Paris, the prince of Troy, to judge their beauty contest. He chose [[LoveGoddess Aphrodite]], but only because she bribed him with the love of the WorldsMostBeautifulWoman, Helen. Unfortunately, Helen was already married, and when she and Paris ran off, her husband Menelaus led all of Greece to war against Troy. The end result? Ten years of fighting, Troy being razed, and even many of the victors dying or suffering on the journey back home.
** For that matter, Helen herself; she only has a few scenes in ''Literature/TheIliad,'' and mostly just lounged around in Troy while everyone fought over her. Even Paris wasn't the city's main fighter; his brother Hector was the protagonist of the Trojans' side.
** ''Literature/TheOdyssey'':
*** The Laestrygonians are only around for about four paragraphs and are never mentioned before or again. However, they have by far the largest impact on Odysseus's followers of any of the threats he faces, reducing Odysseus's fleet down to a single ship; it's this massive turn of events that causes Odysseus to seek the land of the dead.
*** Helios only appears for one scene, but ends up being responsible for the destruction of Odysseus's last ship, and his exile on the island of Calypso.

[[folder:Newspaper Comics]]
* ''ComicStrip/{{Retail}}'':
** Regional manager Lara Silver only appears in two story arcs (and one of them was only via telephone) but her presence leads to the two biggest changes to the status quo at Grumbel's: Marla's promotion to store manager (and Stuart's to district manager), and [[spoiler: the beginning of the end of Grumbel's when announcing the first wave of store closures.]]
** Kate, the store manager at another Grumbel's, only appears via phone in a few strips, but her asking Marla if she heard the rumors about [[spoiler:Grumbel's closing some stores]] is what kicks off that storyline.
** An unnamed store manager appears in literally ''one'' strip, but him inadvertenly revealing that a store that has less volume than Marla's has a stockroom supervisor leads to a chain of events that lead to Cooper being promoted to stockroom supervisor.

[[folder:Podcasts]]
* Nikolai Darius was a small time supervillain of the ''Podcast/RedPandaAdventures'' known as Doctor Bumblebee. He was one of the first supervillains the Red Panda faced in the series' backstory, and only made one appearance in-person as MonsterOfTheWeek in the episode "Flight of the Bumblebee". However, his impact on the series as a whole can not be understated. The exoskeleton he invented and used in his first run as Doctor Bumblebee was taken by the Red Panda and its technology used to create many of his own crime fighting gadgets, such as his trademark static shoes which let him and the Flying Squirrel climb sheer surfaces and do {{Roofhopping}}. In his appearance in the show, he's created a SuperSerum that eliminates hunger and even gives superpowers. This serum is co-opted by the Canadian military to try and create super soldiers for World War II. It creates the MonsterOfTheWeek in "Barbarian at the Gates," as well as the superheroes Mr. Amazing and the Black Eagle, the latter of whom would succeed the Red Panda as the protector of Toronto.
* Despite being a seemingly-random person whose sole contributions to the plot were visions of the future, racking up a huge gambling debt, and ill-advised thefts, John Peters of ''Podcast/PretendingToBePeople'' sets off a sizable chunk of the show's subplots.

[[folder:Professional Wrestling]]
* Two related to Wrestling/TheNationOfDomination:
** The first one was Faarooq hiring then unproven newcomer Rocky Maivia. The young athlete would undergo a FaceHeelTurn and transform into [[Wrestling/DwayneJohnson The Rock]], who would a) [[DragonAscendant strip Farooq out of the leadership]], b) become one of the two biggest stars of the Wrestling/AttitudeEra, and c) become a multi-time WWE World Heavyweight Champion.
** When Rocky added Wrestling/OwenHart into The Nation, it was to get backup in his feud with Wrestling/DGenerationX. This would lead to one of the biggest and most reoccuring rivalries in Wrestling/{{WWE}} history, between The Rock and Wrestling/TripleH.
* Wrestling/{{WWE}} is, by its own nature, a male-centered show, with the Divas usually not having a major impact on the main-event storylines. However...
** Did you enjoy watching ''[[Wrestling/WWERaw Monday Night Raw]]'' between 2002 and 2005? Well, you have Wrestling/StacyKeibler to thank for a small part of that. In 2002, Keibler came to ''[[Wrestling/WWESmackdown Thursday Night SmackDown]]'' as General Manager Wrestling/StephanieMcMahon's executive assistant. But what no one knew at the time was that Keibler had actually been signed to ''Raw'', and was only on ''[=SmackDown=]'' as ''Raw'' General Manager Wrestling/EricBischoff's corporate spy. While in Stephanie's office, Stacy forged a number of documents that made it appear as if certain ''[=SmackDown=]'' Superstars had, like her, actually contracted with ''Raw''; fatefully, two of these Superstars were Wrestling/{{Batista}} and Wrestling/RandyOrton. This didn't result in anything huge at first, as Batista became a "Deacon" and one of Keibler's allies in Wrestling/TheDudleyBoys faction, while Orton was injured soon after his debut and had his career sidelined for the rest of the year. But in early 2003, Wrestling/TripleH and Wrestling/RicFlair introduced both of these men as the junior members of their new Wrestling/{{Evolution}} stable. Batista and Orton proved quite useful to HHH, to say the least: they helped him retain his World Heavyweight Championship for far longer than he deserved, and against the likes of Wrestling/ScottSteiner, Wrestling/BookerT and Wrestling/{{Goldberg}}. They also played a crucial role in causing Wrestling/{{Kane}} to lose the match whose stipulation was that he would have to unmask, costing Kane what last shreds of his sanity remained so that he turned against his brother and former ally Wrestling/TheUndertaker and buried him alive -- causing 'Taker to be resurrected as his "Deadman" persona once again in 2004 after having been a biker character for the past four years. And of course, Evolution would set the stage for the titanic power struggle between HHH and Orton, which started in 2004 and continued off and on for nearly five whole years after that! (The two wouldn't bury the hatchet permanently until 2013, when they joined forces as members of The Authority.)
** Wrestling/AliciaFox killed Wrestling/{{Edge}} in 2008. Well, indirectly, and only temporarily. It was the videotape of her being romanced by the Rated-R Superstar on the day of his wedding to then-General Manager of ''[=SmackDown=]'' Wrestling/VickieGuerrero (leaked by Triple H during the ceremony) that caused Vickie to turn vindictively on her fiancé and rehire the Undertaker (who had been [[TenMinuteRetirement permanently banished from WWE about a month earlier]]), whom she then pitted against Edge in a main event Wrestling/HellInACell Match at that year's ''[=SummerSlam=]''. In that match, the Undertaker chokeslammed Edge right through the ring that created a hole, and then caused flames to erupt from it, the implication being that Edge had literally been sent to Hell. But bringing 'Taker back was the worst possible thing that Vickie could have done, since the "Deadman" turned his wrath on her as well as Edge (he having much more reason to hate ''her'', after all). His attempt to choke Vickie's soul out of her body resulted in Wrestling/TheBigShow turning heel to save her, which, in turn, resulted in Big Show becoming Vickie's new boyfriend, until [[JokerImmunity Edge returned]]. This sparked a bitter feud between Undertaker and Big Show that lasted for the rest of the year and continued into 2009 before Vickie and Edge got back together.
** Wrestling/AJLee has perhaps exerted the greatest direct influence on WWE of any Diva in history:\\
An inadvertent blow to the neck from Wrestling/TheBigShow nearly crippled her, turned boyfriend Wrestling/DanielBryan into an overprotective and possessive jerk, and ultimately caused Bryan to lash out at Lee for nearly everything she did, including his losing the World Heavyweight Championship in 18 seconds to Wrestling/{{Sheamus}} at ''Wrestling/WrestleMania'', thus leading Bryan to virulently dump AJ on the following week's episode of ''Wrestling/WWESmackDown''. Daniel's cruelty apparently caused AJ's mind to snap, [[SanitySlippage resulting in her behavior becoming ever more erratic]] and her profile on television to rise, as airtime was steadily eaten up by her bizarre antics. Indeed, AJ was transformed into such an outrageous scene stealer that Wrestling/VinceMcMahon appointed her as General Manager of ''Wrestling/WWERaw'' later that summer -- much to the chagrin of Daniel Bryan, who had assumed that she had agreed to marry him in the ring when in fact she had accepted the GM position.\\
This cruel prank, in turn, caused Bryan to lose his mind, which in turn led to him having to seek psychological group therapy along with Wrestling/{{Kane}}... which culminated in the two of them forming a comedic tag team called Wrestling/TeamHellNo that [[HeelFaceTurn turned both characters face again]]. This marked the beginning of Daniel Bryan's true rocket to stardom in WWE, making him so popular that not only did he go on to win the WWE Championship three times, but when he was respectively excluded from and (relatively) quickly eliminated in the 2014 and 2015 Wrestling/RoyalRumble matches, fan disillusionment ran so deep that the WWE Universe turned virulently on the men who did win those matches: Wrestling/{{Batista}} and Wrestling/RomanReigns. While Batista turned this situation into heel heat for what eventually led to Bryan's title win at ''[=WrestleMania=] 30'', Reigns never regained the adoration he had during his days with Wrestling/TheShield, [[XPacHeat is still heavily booed despite being a face]], and has had to acknowledge that fact within kayfabe.\\
Also affected by AJ-mania? Wrestling/DolphZiggler, whose popularity was heavily propelled by AJ becoming his manager in December of 2012, leading him to his first true World Heavyweight Championship reign. Also, Wrestling/TheNewDay, an enormously popular trio that might have not existed if Wrestling/BigELangston was never given the role he got in the Ziggler/Lee faction. Not to mention, the breakup and solo success of the members of The Shield, as without the formation of Wrestling/TheAuthority and the return of Wrestling/{{Evolution}}, which can respectively be attributed to Bryan's rise to popularity and the outcry over Batista winning the Rumble (which as previously mentioned was largely because of Bryan’s absence from the match), their arc would not have played out the same.
** Wrestling/{{Paige}}'s actions as ''[[Wrestling/WWESmackdown Smackdown Live!]]''[='=]s General Manager played a huge role in the creation of [[Wrestling/BeckyLynch "The Man"]]. She booked a Triple Threat match where the champion Wrestling/{{Carmella}} would face Becky and Wrestling/CharlotteFlair for ''Wrestling/{{Summerslam}} 2018''. At the end of said match, with Charlotte stealing the victory and the championship from her hands at the last minutes of the match, and feeling that everything she worked for has been stolen again, Becky [[FaceHeelTurn turned heel]] on Charlotte, and their friendship was destroyed. This, in turn, would lead to the revamp of Becky as a Wrestling/StoneColdSteveAustin-like character (with the audience ''refusing'' to boo her), a series of well-received matches against Charlotte (including a [[Wrestling/TheWrestlingObserverNewsletter four-and-three-quarter-star-rated]] Last Man Standing match at ''WWE Evolution''), the Twitter feud with Creator/RondaRousey, Becky being injured by Wrestling/NiaJax in the ''Raw'' go-home episode for ''Wrestling/SurvivorSeries 2018'' (and the resulting injury from Nia's botch making Becky look like a warrior), Becky being left out of ''SS'' due to said injury, and the main event of ''Wrestling/{{WrestleMania}} 35'' being changed from Ronda vs. Charlotte into a Triple Threat match with Becky inserted as a challenger between the two champions in a "Winner Takes All" match... which she won, resulting in Becky being the first Women's Champion holding both the Raw and Smackdown Women's titles at the same time and becoming [[TheAce the new face]] of [[Wrestling/WWENewEra the WWE's "New Era"]]. Oh, and if that wasn't enough, in RealLife, her new persona being called "The Man" led to a series of Twitter quips with Wrestling/SethRollins, who also called himself "The Man"... and who eventually not only would become his boyfriend, but also the father of her child.
* The Big Show heel turn mentioned above had another bit player besides Alicia Fox. [[Wrestling/LondonAndKendrick Brian Kendrick]] won a match to qualify for a WWE championship shot against Triple H. Big Show thought he won, so he stepped out of the ring over the top rope and walked back to the locker room. Little did he know Kendrick was being hoisted on his bodyguard Ezekiel Jackson’s shoulders. After Show left ringside, Kendrick was rolled back into the ring to claim victory. Frustration over this loss ultimately may have caused Show to snap that fateful night.
* [[https://twitter.com/TheWWEGuy_/status/864542537360474112 A random guy on Twitter]] doing a question to [[Wrestling/TheWrestlingObserverNewsletter Dave Meltzer]] led to [[https://twitter.com/CodyRhodes/status/864546973461950465 a bet]] with Wrestling/CodyRhodes which also involved Wrestling/TheYoungBucks. A year later this strange chain of events led to the creation of ''All In'', the biggest indie PPV, and half a year later, it ended up in the creation of Wrestling/AllEliteWrestling, the first serious competitor to the WWE ever since the end of WCW.
* Despite his run with Wrestling/BulletClub lasting less than a year before he left NJPW for WWE, Wrestling/FergalDevitt (WWE's Finn Bálor) influence on the course of the stable's and the company's history can be felt nearly five years following his departure:
** The foundation he created for Bullet Club with its Wrestling/TheKliq-style covenant motif enabled Wrestling/AJStyles to seamlessly step into the front seat the same night he departed and complete the dream of BC winning the IWGP Heavyweight Championship on its official one-year anniversary. The camaraderie, cool T-shirt, and general badass antics of the Club, all of which were established by Devitt and his friends, combined with the high-profile presence of Styles in his stead, made them a worldwide phenomenon so powerful that taking the name of Bullet Club as a cash cow became a central part of Wrestling/KennyOmega and Wrestling/TheYoungBucks' "world-changing" agenda when it was time for Styles and The Good Brothers to leave; and even after The Elite's antics became too much to be sustainable within the group's core values, rather than dying out or letting them fully absorb the title of Bullet Club, the core members he started with were able to band together and hatch a successful plan to take The Club back.
** The biggest seed of Devitt's influence, however, would come where Wrestling/JayWhite, the young man who tagged with Devitt once in the United Kingdom and impressed him so much that The Prince got Jay in touch with Bad Luck Fale to bring him into NJPW, would step forward and take his place at the front of Bullet Club as the culmination of both the BCOG/Firing Squad scheme and White's personal mission to sabotage rival faction CHAOS. White would then bring the same IWGP Heavyweight Championship back to Bullet Club in short order, winning it from Wrestling/HiroshiTanahashi just over a month after Tanahashi claimed the title from a departing Omega, validating his ascent as The Club's true weapon of choice to succeed Devitt after Styles. And Devitt responded by Tweeting his name and wearing the same color ring gear as him. This has only strengthened with the addition of KENTA at the end of the 2019 G1 tour.
** And if all of the above aren't enough, The Elite being ousted from the stable (and later New Japan itself, though this was because [[RealitySubtext the Elite decided to let their contracts with]] Wrestling/NewJapanProWrestling and Wrestling/RingOfHonor [[RealitySubtext run out and not re-sign]]) ''also'' led to the creation of Wrestling/AllEliteWrestling. [[TheButterflyEffect A WWE superstar created the stable that would, in turn, create the first serious rival for the WWE ever since the folding of WCW.]]

[[folder:Puppet Shows]]
* ''Series/PiliFantasyWarOfDragons'': The masked martial artist Ouyang Lin. [[spoiler:She finds and frees the Sacred Dragon Bone Sword, and convinces Yeh Hsiao-chai to forgive Su Huan-chen.]]

[[folder:Theatre]]
* ''Theatre/JasperInDeadland'':
** Jasper and Agnes talk about their parents in scenes that are vital to the plot and/or their character development; when Cerberus demands to know what it means to be human, Jasper describes his parents as proof that HumansAreBastards. When Ammut makes Jasper confess his greatest misdeeds, he admits he fears he could have stopped his mother leaving and helped his father's drug addiction if he had tried. When Agnes regains her memories, [[spoiler:she remembers that her father was abusive after her mother's death, and tells Jasper that they should stay in Deadland]]. Despite this, all of their parents combined have approximately ''a minute'' of time on stage.
** Ammut is but one of many mythological characters Jasper meets and only appears in one scene, but her tearing out Jasper's heart to weigh it, and then crushing it out of spite, factors heavily into the climax.
* ''Theatre/KingLear'':
** Cordelia appears in just four scenes but she's Lear's clear favourite daughter, and his disinheriting her kicks off the whole plot.
** Regan's husband Cornwall gets killed off at the end of Act III but not after he's gouged Gloucester's eyes out, among other villainous acts.
* During "At the End of the Day," a song in ''Theatre/LesMiserables'', a nameless factory worker snatches a letter from Fantine for no particular reason and reads it aloud to taunt her. The letter reveals that Fantine has an illegitimate daughter, which in turn gets her fired, which in turn forces her into prostitution, which in turn prompts Valjean to pity her, which in turn makes him on the scene to save a man from a runaway cart, which in turn makes Inspector Javert reveal that a man he thinks is Valjean has been arrested, which in turn makes Valjean decide to turn himself in ''and'' promise to care for the dying Fantine's daughter, which in turn...you know what, it's probably easier to simply say that the Nameless Factory Worker is the most important character in the show.
** Then there's the Bishop, who sets Valjean on a path of righteousness for the entirety of the play. Without him Valjean would likely have continued his self-destructive spiral until rejailed or killed, Fantine would have been arrested and died in prison, Cosette would have stayed with the Thenardiers, causing her to never meet Marius, who would more zealously assist the revolutionaries and die among them. Curiously, Eponine ''might'' have survived the show, not ever reaching the DespairEventHorizon caused by Marius and Cosette's relationship. In any case, the Bishop is onstage for around three minutes, tops.
** And General Lamarque, Les Amis de'l ABC's only ally in the military. He never appears onstage, is dying when we first here of him, and yet, his death is what spurs Enjolras into starting the revolution.
* In ''Theatre/TheMagicFlute'', the Queen of the Night only appears in three scenes (and the opera counts them in the "[[OurActsAreDifferent French scenes]]" way). Two of them consist entirely of an extravagant coloratura aria (and many people only remember the second one). The third is a small part of the second act finale in which she gets in only a few lines before her final defeat.
* Jessica, daughter to Shylock in ''Theatre/TheMerchantOfVenice'', has very few lines, but the whole play hinges on her elopement and her conversion to Christianity, which drive her dad over the edge. Whether she's seen as a "good" or "bad" character is a key decision when staging the play, and directors tend to give her plenty of extra stage time to pray in Hebrew or look tragic. Lorenzo could also be seen this way -- besides being the boy who steals Jessica, he has one of the play's best soliloquies ("How sweet the moonlight sleeps upon this bank...")
* The titular character in ''Theatre/ThePhantomOfTheOpera'' thoroughly dominates the musical -- and yet is only onstage for 30-40 minutes of a two and a half hour production.
** Also, Joseph Buquet really doesn't do much while he's alive besides loom about the place, tell the corps de ballet scary stories about the Phantom and set up the ChekhovsGun of the Punjab lasso -- but his shocking death is the final nail in the coffin of Christine deciding the Phantom is ''bad'' news and choosing Raoul; all (further) hell breaks loose from there.
* It's easy to forget that Tybalt from ''Theatre/RomeoAndJuliet'' is only in about 3 scenes in the play. But as Creator/IsaacAsimov pointed out succinctly in his analysis of the play, without Tybalt, the rest of the play's events would never have happened.
** Remember that there was more than one friar? Of course not, because Friar John is in one scene and has about five lines. But because he fails to deliver a letter to Romeo, the tragedy of the climax is allowed to unfold.
*** Not to mention the apothecary, who provides the reason Romeo is dead.
* Joe in ''Theatre/ShowBoat''. It helps that he has [[MinorCharacterMajorSong one of the best Broadway songs ever written]], "Ol' Man River."
* In both the play and film versions of ''Theatre/SixDegreesOfSeparation'', Trent Conway appears in only one scene, but it's because of his information that Paul is able to insinuate himself in the other characters' lives.
* ''Theatre/WesterosAnAmericanMusical'': A frequent consequence of reducing the roles of some characters compared to the source material:
** Lancel Lannister is given all the credit for actually killing Robert, but only gets a brief mention in "Plot Development".
** Tyrion mentions his life getting saved by his squire near the end of "The Siege of King's Landing". The squire in question isn't heard of before nor after the fact.
** Robb's wife isn't seen at all, but the fact that she [[spoiler:isn't a Frey]] has a huge impact on the Stark storyline.
* In ''Theatre/TheWintersTale'', Antigonus was ''supposed'' to kill a small baby, but, unable to do so, he left it in the wilderness instead (mostly because he was [[ExitPursuedByABear eaten by a bear]] before he could do anything else). That baby ends up being the hero of the story.
[[/folder]]

[[folder:Theme Parks]]
* The ''Parasaurolophus'' in ''Ride/JurassicParkRiverAdventure'' at Ride/UniversalStudios, despite only appearing in one scene, launches the whole conflict of the ride when it knocks the guests off course.
[[/folder]]

[[folder:Video Games]]
* ''Franchise/AssassinsCreed'' has Khemu, the son of Bayek and Aya who is murdered by the Order of the Ancients. His death is what motivates his parents to go on a RoaringRampageOfRevenge against the group and form the Hidden Ones, the ancient precursors to the Assassin Brotherhood who would become TheRival to the Templar Order.
* Bane in ''VideoGame/BatmanArkhamAsylum''. His only appearance is a brief confrontation, but [[spoiler: his Venom serum]] is the catalyst for the game's plot.
** The same could be said for the Electrocutioner in ''VideoGame/BatmanArkhamOrigins''. The fight with him ends with you hitting him and him hitting the ground, and then [[spoiler: he's unceremoniously killed off by the Joker]], but the weapons you get from him, the Shock Gloves, have a heavy impact on the rest of the game. Not only are the Shock Gloves [[GameBreaker just that awesome]], but they also allow Batman to [[spoiler: save Alfred's life, as well as enable him to get around the Joker's SadisticChoice by TakingAThirdOption.]]
* In ''VideoGame/TheBindingOfIsaac: Repentance'', the first of the {{True Final Boss}}es that you face upon reaching [[spoiler:Home]] is Dogma, which represents [[spoiler:the televangelism that not only drove Isaac's mom insane, but led to Isaac's own self-loathing and suffering]]. Despite only showing up in the final level of this game's final DLC, [[GreaterScopeVillain Dogma has done more to cause the story of Isaac]] than any other enemy that Isaac has faced.
* ''VideoGame/{{Bloodborne}}'':
** The Blood Minister only appears in the opening cutscene and is never mentioned again, but he's the one who got you to sign a hunter contract, allowing the rest of the game to take place.
** Gehrman, the closest thing the game gives you to a MissionControl, only shows up about four times in the game[[note]] (he sometimes pops up in the garden at random times, but he's always sleeping)[[/note]], two of which are to direct you to things that aren't even necessary to complete the game (though they are necessary [[spoiler: for the GoldenEnding, and to completely understand the story]]). However, he's also the one who ''founded'' the Hunters, made all of the early game weapons and Hunter Tools, and [[spoiler: was part of the group that inadvertently ''created'' the Beast Plague. His pact with the Moon Presence is also what creates the Hunter's Dream, and what gives you your powers as a Hunter. Finally, he's also the penultimate boss in the ''Childhood's Beginning'' end, and the FinalBoss in the ''Honoring Wishes'' ending]].
** [[spoiler:Mergo's Wet Nurse]] counts for this as well. Maybe. [[KudzuPlot It's difficult]] [[MindScrew to say for sure.]] The entity itself goes completely unmentioned in lore notes and only appears as [[spoiler:the Final Boss in the Neutral Ending, or the Penultimate Boss in the Bad Ending]], making it come across as a GiantSpaceFleaOutOfNowhere, not helped by the fact that, unlike all other beings in the game, it doesn't bleed when struck, instead giving off dark, dusty clouds, almost as if it's just an illusion... The fact that it is [[spoiler:the Wet Nurse of [[GooGooGodlike Mergo]]]] alone makes the entity a significant one however, and while it goes unmentioned in the Lore, there's [[spoiler:a very prominent statue in the Grand Cathedral sporting the signature robed, winged, headless traits of the Wet Nurse; a statue that pours a liquid down upon the main altar and the worshipping effigies below, which may represent the Wet Nurse bestowing the Healing Church with Old Blood, a possibility that's reinforced by the fact that the Wet Nurse dons a pendant bearing a striking resemblance to the Communion Rune]]. The fact that it does not bleed [[spoiler:may also qualify it as "the bloodless" that the Fishing Hamlet Priest calls to]] in the Old Hunters DLC. Finally there's the fact that [[spoiler:the Wet Nurse's invisible nature, namelessness and potential ties to Blood Ministration makes it one of the prime candidates for being Formless Oedon... which, if true, would make it the GreaterScopeVillain of the entire game]].
** Laurence, the First Vicar, only appears in a short cutscene (and since it's only really his arm onscreen, his model is actually Micolash). But he founded the Healing Church, source of the Blood Ministration that makes you a Hunter and also cause of most of Yharnam's problems. [[spoiler: He does appear in ''The Old Hunters'' [=DLC=], [[KarmicTransformation having turned into the first Cleric Beast because of the Old Blood]] the Healing Church used.]]
** Ludwig, the first Church Hunter, is the one who organized the system of Hunting that Yharnam uses to stave off beasts, and is the one behind several weapons, but never appears in the game and is probably dead or a beast himself. [[spoiler: He too shows up in person in ''The Old Hunters'', as the boss [[FallenHero Ludwig the Accursed]]/[[RestorationOfSanity Ludwig, The Holy Blade]].]]
* Yakra XIII from ''VideoGame/ChronoTrigger'', who [[spoiler:impersonates the Chancellor from 1000 A.D. to take {{Revenge}} on the Guardia lineage for the death of his ancestor from 600 A.D.]], attempts to frame [[TheProtagonist Crono]] for the abduction of Marle and get him executed, which leads to Crono, Marle and Lucca taking the Gate to the [[BadFuture ruined future]] of 2300 A.D. and finding out about [[BigBad Lavos]]. The group doesn't get the chance to fight Yakra XIII until after [[spoiler:Crono is resurrected on Death Peak after being killed by Lavos in the Ocean Palace]], and his fight is [[{{Sidequest}} completely optional]].
* ''VideoGame/DeadRising'': Larry the cannibalistic butcher comes out of nowhere and [[spoiler:kills Carlito, the BigBad of the entire game,]] in his only appearance.
* ''VideoGame/DragonQuestXI'': [[StarterVillain Jarvis]] is encountered very early on and dealt with in minutes, but he's the reason Veronica spends the whole game [[FountainOfYouth in the form of a child]].
* ''VideoGame/Fallout3'': The player character's mother, Catherine. She has roughly 3 lines, [[DeathByChildbirth dies within a minute of your birth]], and is the driving motivation for James' escape from the vault ([[spoiler:and trying to restart Project Purity]]) and, consequently, your reason for doing the same.
* ''VideoGame/FatalFrame'':
** Kunihiko Asou. He was an occult philosopher and brilliant researcher, focusing on Japanese folklore and the spirit world during the second half of the 19th century. Despite not even physically appearing until the fifth game, Asou has influenced the entire franchise. He is the creator of the Camera Obscura, as well as other tools to battle against spirits, and left them to his descendants. And outside of this general influence, his personal interaction with Ouse Kurosawa was among the reasons her ritual failed, cursing Mt Hikami.
** Mafuyu Hinasaki. His role for the entire game mostly consists of a minor tutorial, before [[DecoyProtagonist focus shifts]] onto Miku, and to eventually choose to remain behind with Kirie at the Hellgate. However, his sacrifice and actions cause Miku huge amounts of guilt and grief, to the point that they are the reason Miku ends up wandering the Manor of Sleep in the third game, and even influences her actions in the fifth game.
* Marisbury Animusphere from ''VideoGame/FateGrandOrder''; the [[PosthumousCharacter deceased founder]] of the Chaldea Security Organization which the protagonist and Mash Kyrielight are members of, he [[spoiler:won the [[VisualNovel/FateStayNight Fuyuki Holy Grail War]] in 2004 with King Solomon and allowed his Servant to have his own wish, setting up the eventual defeat of the game's primary antagonist by using Solomon's final magic ring as a catalyst and leaving it behind for Solomon after his death. He's also revealed to have signed off on several projects with several consequences in the present, with Mash being a Demi-Servant because of his attempts to protect the future by creating a Heroic Spirit army and human experimentation in a private oil rig unintentionally providing the means and power of world-ending threat Kiara Sesshouin.]]
* Reddas in ''VideoGame/FinalFantasyXII''. [[spoiler:His backstory reveals that he was the one Judge who nuked Nabradia with nethicite, and that leads to such a hatred of it that he destroys the Sun-Cryst, banishing the Occuria's influence from Ivalice and, in a sense, completing the BigBad's not-so-evil plan.]]
* ''VideoGame/FinalFantasyXIV'': A certain raid boss ends up being the key to half the story. [[spoiler:Omega is an alien war machine that chased Midgardsormr from their homeworlds across an unknown, but enourmous, distance to Hydaelyn. Upon landing, it became the basis for all the technology of the Allagan Empire. It's at the root of plot elements in ''A Realm Reborn'' (the Ultima Weapon was based on it), ''Binding Coils of Bahamut'' (it captured Bahamut and put it in Dalamud), ''Crystal Tower'' (the tower's technology was derived from Omega) ''Heavensward'' (it's the reason there are dragons in the world to begin with), ''Stormblood'' (made the liberation possible by destroying Baelsar's Wall during its fight with Shinryu) and ''Shadowbringers'' (the techniques used to summon the Tower and the Scions to Norvrandt were developed by studying Omega's Rift manipulation ability).]] Despite all this, its only direct appearances are [[spoiler: at the end of ''Heavensward'' where it fights Shinryu and disappears, and its eponymous raid series in ''Stormblood'' where the player gets to fight it.]]
* Argath in ''VideoGame/FinalFantasyTactics'' is a noble and squad member of Ramza's party in the beginning of the game. He absolutely cannot stand commoners and believes only those with noble blood have the right to rule. Ramza eventually kicks him out of the group, but this causes Argath to work with Zalbaag and, in a hostage situation later on, is given the order to shoot through Tietra to kill a member of the Corpse Brigade. Argath's murder of Tietra gets him killed by Delita and Ramza, but Argath's actions causes major shifts in Delita and Ramza's characters; Delita distrust all nobles and works to overthrow them from behind the scenes so that he can rise to power and make things right. Ramza distances himself from his brothers and begins work as a mercenary while still fighting for justice.
* ''VideoGame/FireEmblemAwakening'', as is the norm for the series, has a massive cast with most of the characters having little to no actual part in the storyline. Early on in the game, Maribelle, who herself has only a ''slightly'' larger part than most of the other playable units and loses all plot relevance shortly into the game, is held hostage by Plegia and used as a [[TheScapegoat scapegoat]] to start its war with Ylisse, kickstarting the storyline as a whole.
** Previously in ''[[VideoGame/FireEmblemTheBindingBlade Binding Blade]]'' and ''[[VideoGame/FireEmblemTheBlazingBlade Blazing Blade]]'', there was King Desmond of Bern. He only appeared for one chapter of the latter game, but it mainly highlighted how much of an [[AbusiveParents abusive father]] he was to his son Zephiel, initially TheAce and an overall NiceGuy, to the point of attempting to have him assassinated multiple times. [[spoiler:By the time ''Binding Blade'' rolls around, Zephiel is now the BigBad, having become [[MisanthropeSupreme so disillusioned with humanity]] due to Desmond's abuse and neglect that he starts a war to KillAllHumans and have dragons rule the world in their stead.]]
** All the way back in [[VideoGame/FireEmblemShadowDragonAndTheBladeOfLight the first game]], there's Bantu. A Manakete who can't even fight unless you find an optional item, he's not much of a character. But you need to recruit him in order to [[SkippableBoss save Tiki]], since he's the one who unsealed her and the only one who can recruit her. Tiki goes on to be a ''major'' character throughout the series.
* The "Oriental Gentleman" from ''VideoGame/GrandTheftAutoIII'', an [[NoNameGiven unnamed]] man who just so happens to be a prisoner in the same police convoy the player character is in -- the fact that the game consists of typical ''VideoGame/GrandTheftAuto'' fare rather than the player being behind bars for the whole game (or at least a few minutes, considering the series) is because the Colombian Cartel decided to hold up the convoy and take this one prisoner.
** Similarly, Brad from ''VideoGame/GrandTheftAutoV''. He [[spoiler: only has 2 appearances, one in the prologue and one in the mid-game as a corpse, but he's the reason Michael was able to fake his death and move to Los Santos as he was buried in place of Michael, for which Trevor and Michael became enemies for most of the latter half of the game after the former found out what Michael did to get his current life.]]
*** Also, Simeon Yetarian. His illegal attempt to repossess Jimmy's car is the entire reason Michael and Franklin meet, thus indirectly setting the plot of the main game.
*** Kyle Chavez as well. If Amanda hadn't cheated on Michael with him, thus Kyle hiding in a mansion, Michael won't have tore the said mansion down and incurred the wrath of Martin Madrazo, the real owner. Michael then conducts a heist at the jewelry store just to pay Martin back, causing Trevor to return to Los Santos and [=FIB=] hiring the trio for their dirty work and Devin Weston recruiting them for his own goals.
* The G-Man of ''VideoGame/HalfLife'' fame features, in the main, only in the intro and outro cutscenes of each game -- his other appearances are mostly of the "you spot the G-Man in the distance, he walks behind a corner and vanishes" variety. (He does have a significant scene in the middle of ''Episode 2'' when he gives Gordon a "heart-to-heart".) Everything about him is mysterious, but he's widely suspected of being responsible for, literally, the entire plot of the series from start to finish. [[LeftHanging Well, as finished]] [[DevelopmentHell as it'll ever be.]]
* ''VideoGame/TheHangedMan'' has George Schmid, whose full name only comes up twice. Once on a quote written on a photograph, and once as the owner of a black notebook that Ed is looking for. George was one of the inmates living in the asylum-turned-homeless-shelter, and began to come up with the idea that society considered people like him to be 'bad', and made themselves happy by shoving them into this shelter. This made him think that the unhappy inmates could do something similar; by killing the 'bad' inmates, the others could 'become happy again'. His twisted thinking [[GreaterScopeVillain resulted in the Happy Murders, which caused the shelter to be shut down and abandoned for good]]. Having written this 'method' into his notebook, he sparks a desire in Ed to return to the shelter and look for the notebook. [[spoiler:Which results in [[BigBad Ed]] planning to kill Will, and Keith in some endings, to 'become happy again', before he heads to the police and atones for having killed his father.]]
* Jason in ''VideoGame/HeavyRain'' is one of two sons to Ethan. Jason is introduced in the prologue and is quickly killed off in a freak accident via being hit by a car, even though Ethan tried to jump in front of the car to save him. Despite Jason's very short screen time, his death kickstarts the entire plot. [[spoiler: Scott Shelby, who couldn't save his brother when they were both kids due to their abusive and neglectful father, wanted to find a father that would do anything for their sons. Scott witnessed Ethan's attempt to save Jason, giving him the idea of kidnapping a bunch of young boys and slowly drowning them in [[DrowningPit a pit being filled with rainwater]] unless their fathers can find and save them. Thus the Origami Killer was created.]]
* In ''VideoGame/HorizonZeroDawn'', it's revealed through a collectible that [[spoiler:an unnamed programmer made the machines code uncrackable, which meant that if they glitched (which they eventually did), there was no way to regain control of them.]]
* ComicBook/TheJoker from ''VideoGame/InjusticeGodsAmongUs'' only appears in a single cut-scene in the game itself and the first four panels of the prequel comics before being killed by Superman but it is ultimately his actions to nuke Metropolis, murdering Lois Lane and Jimmy Olsen, and corrupt Superman that kickstarted the events of the ''Injustice'' universe. Of course, there's ''another'' Joker running around, but he's from the main universe.
** And while the ''Injustice'' version of Joker appears as a fear-induced hallucination in ''VideoGame/Injustice2'', his role as TheCorrupter towards Harley Quinn is still felt there, as is his twisted legacy of causing Supes' StartOfDarkness.
* ''VideoGame/KingdomHearts358DaysOver2'': Riku spends most of the game absent, and when he does show up occasionally he doesn't do much. However, his interactions with Xion [[spoiler:make her realize that she needs to give up her existence and return to Sora so he can wake up]].
* The [[Franchise/ToyStory Toy Box]] world in ''VideoGame/KingdomHeartsIII'' seems to be another Disney world for Sora to visit with the appeal of a ''Verum Rex'' brand featuring Yozora as the main character. [[spoiler:However, it later turns out that Yozora is RealAfterAll where he appears both in the Secret Ending as well as a BonusBoss as a SequelHook character. In other words, the entire Toy Box world serves as an EarlyBirdCameo for a character who undoubtedly becomes significant in the sequels]].
* ''VideoGame/KnightsOfTheOldRepublic'': Trask Ulgo is dead before the end of the tutorial level, charging into a hopeless battle against Darth Bandon in order to buy the PlayerCharacter time to escape. There's a passing mention by a Hutt in game about the "Ulgo" noble house of Alderaan. Come ''VideoGame/StarWarsTheOldRepublic'', that incident drives almost every arc on Alderaan! A distant relative of Trask's declares himself king, and asserts Alderaan's independence from both the Republic ''and'' the Sith Empire, with Trask remembered on Alderaan as a martyr who was betrayed by both factions.
* Joel's daughter Sarah dies roughly 20 minutes into ''VideoGame/TheLastOfUs'' but the trauma from it is still affecting him 20 years into the future. Over the events of the game, Joel begins to see Ellie as a ReplacementGoldfish for Sarah. It ultimately drives him to [[spoiler: essentially damn the world of its best shot to cure the fungal infection that caused the zombie outbreak. Ellie is immune and having the surgery to get the mutated fungus out of her brain will kill her. Joel rips her off the operating table before the surgery can start because he can't bear to lose another daughter.]]
** [[spoiler:In a similar vein, one of the surgeons who is killed in this scene is named Jerry Anderson. It turns out he has a daughter named Abby, and his death causes her to murder Joel in the opening moments of the sequel.]]
* [[VideoGame/TheLegendOfHeroesTrailsInTheSky Cassius Bright]] makes a small but significant role in ''VideoGame/TheLegendOfHeroesTrailsOfColdSteel IV'' as he ends up forming a SempaiKouhai relationship with [[TheHero Rean]] and [[spoiler:ends up testing to see if his junior is ready to become a [[MasterSwordsman Divine Blade]] which Rean passes with flying colors. He's also commanding the army resisting against the Erebonian Empire who are at war against the entire Western Zemuria continent because of events that had happened in ''Cold Steel III'' (an attempted assassination to the emperor happens and the perpetrator used a gun made in Calvard) and is buying time for the heroes to save the day.]]
* ''Franchise/TheLegendOfZelda'':
** The King of Hyrule in ''VideoGame/TheLegendOfZeldaOcarinaOfTime'' is never seen on screen, but is shown meeting with [[BigBad Ganondorf]] in Hyrule Castle. Princess Zelda has visions where she sees Ganondorf stealing the Triforce, but [[CassandraTruth her father doesn't believe her]] when she tells him what she saw. Had he actually listened, [[CouldHaveAvoidedThisPlot the events of the entire game could have been prevented]].
** In ''[[VideoGame/TheLegendOfZeldaOracleGames The Legend of Zelda: Oracle of Ages]]'', the original purpose of Queen Ambi's EvilTowerOfOminousness, the construction of which led to her corruption and eventual possession by [[BigBad Veran]], was a lighthouse to guide her unnamed sailor sweetheart back to her. Who's that character? The unnamed skeleton pirate captain from ''Oracle of Seasons''.
** ''VideoGame/TheLegendOfZeldaBreathOfTheWild'':
*** [[WanderingMinstrel Kass's]] teacher. An unnamed PosthumousCharacter, he is responsible for teaching Kass the various songs the latter uses to guide Link in uncovering Shrines. Furthermore, [[spoiler:a century ago he was a HopelessSuitor for Princess Zelda who resented Link for being the object of her affections instead of him; Kass's revelation of this makes it clearer than at any other point that she was in love with Link]].
*** One character from a previous ''Zelda'' game manages to make a surprise appearance in this capacity. [[spoiler:That character being Fi from ''[[VideoGame/TheLegendOfZeldaSkywardSword Skyward Sword]]''. Although her physical form is unseen, she manages to communicate to Zelda in the final Memory when Link is mortally wounded by several Guardians. She manages to provide Zelda with the information needed to save Link from biting it for good.]]
* In ''Lost Ark'', [[HangingJudge Executor Solas]] is a relatively minor antagonist who serves as the ArcVillain for a handful of quests towards the end of the East Luterra arc. However, his actions during those quests end up having major, long lasting consequences for the rest of the story, as [[spoiler:his callous murders are the final straw for Armen, who was already deeply struggling with his half-Demon powers. Armen snaps completely, declares that humanity is NotWorthSaving due to all the death they cause, and willingly joins up with [[TheHeavy Kharmine]] because he now genuinely believe he has no place at the protagonist's side.]]
* The Puppeteer from ''VideoGame/LittleBigPlanet Vita''. You're told early on through {{Exposition}} from Colonel Flounder that he's the BigBad (being the creator of the [[FacelessGoons Hollows]] you see wreaking havoc in the various worlds). Despite this fact, you don't even get to hear him until a cutscene near the end of the final world, which features his recorded voice, and you don't get to see him in person until the final cutscene of the game.
* Scab from ''VideoGame/MadMax2015'', a former War Boy who suffered a crippling injury and was converted into a human blood bag before being sold off by Scrotus, and who wants revenge for being cast aside. He only appears briefly in two scenes, but [[spoiler: his blood saves Max from a fatal injury, and he later tells Max where to find Scrotus for the final confrontation. He even gleefully declares that he's gotten his revenge because it's someone who's received his blood who will kill Scrotus.]]
* In ''VideoGame/MadRatDead'', Mad Rat and Heart come across a group of stray rats in the forest. The only thing their onscreen roles culminate to is yelling about cheese and dying. [[spoiler:However, one of the rats cries out "Thank you Rat God!" as it is killed, giving the player a big clue that the Rat God isn't as benevolent as she seems.]]
* The unnamed Genius Girl seen in ''VideoGame/MarioPlusRabbidsKingdomBattle'' only shows up for a few minutes in the intro [[spoiler:and the 100% ending for the ''Donkey Kong Adventure'' DLC]], but she's the one responsible for building the [=SupaMerge=] machine that sets the entire plot into motion and serves as the main source of conflict. Beep-0, the character you play as during the game's overworld segments, is implied to be one of her creations as well.
* The ''Franchise/MassEffect'' series has several notable ones:
** In [[VideoGame/MassEffect the first game]], it's because of a lazy dockworker named Powell who managed to survive the geth attack on Eden Prime by being asleep behind some dock crates that Shepard's team is able to learn about Saren Arterius going rogue, which results in Shepard being made the first human Spectre and going on to save the colony of Feros by killing the Thorian, defeat [[TheDragon Matriarch Benezia]] and uncovering the return of the rachni at Noveria, destroy a krogan cloing facility on Virmire, and ultimately discover the impending threat of the Reapers.
** In [[VideoGame/MassEffect2 the second game]], it's because of the medical officer Wilson [[spoiler:on orders from his benefactor the Shadow Broker]] sabotaging the systems at Lazarus Station where Cerberus was putting the Commander back together after the destruction of the ''Normandy'', that pushed Miranda Lawson to wake Shepard up ahead of schedule, allowing the Commander to, among many things: cure the [[spoiler:Collector-designed]] deadly plague ravaging the slums of Omega, eliminate three of Omega's strongest criminal gangs while saving Archangel, rescue the genetically perfect krogan Grunt from being destroyed or exploited, protect the remainder of the colonists on Horizon from capture, realize the origins of the mysterious Collectors [[spoiler:as heavily augmented Protheans controlled by the Reapers]], lay the seeds for a lasting peace between organics and synthetics by interacting with the geth called Legion, and ultimately eradicate the Collectors as a major threat ahead of the Reapers' coming invasion.
** In [[VideoGame/MassEffect3 the third game]], it's because of a hanar special operative who tagged along on an Alliance military operation to raid a batarian research facility that was studying Reaper tech unknowingly that there is a chance for two species to go extinct in the midst of the Reaper invasion if certain factors are not present when Shepard confronts the "big, stupid, jellyfish". Namely, if Kasumi Goto was never recruited or did not survive the Suicide Mission in ''2'', then Shepard is forced to make a SadisticChoice between saving the hanar homeworld supporting both the primary species and their cadre of loyal drell aides, or rescuing an affable salarian Spectre that shows a more respectable side of the organization before he's strangled to death.
*** Argubaly, the salarian scientist named Maelon serves as one for both ''2'' and ''3''. He used to be a novice member of Mordin Solus' old research team that made a crucial update to the genophage virus afflicting the krogan race. During Shepard's mission to fight the Collectors, Mordin asks the Commander to help rescue him from a krogan clan, only to find out that not only was Maelon trying to cure the genophage, but he was doing it voluntarily. Mordin can execute him unless Shepard intervenes, after which he disappears, while Mordin is relieved of the mental burden and has better chances to survive the Suicide Mission. Come the Reaper invasion, the data that Maelon gathered doing his experiments proves crucial to finalizing the new cure required to arrange an alliance between the turians and krogan against the Reapers. If Shepard convinced Mordin to keep the data, then the female krogan survives the development process and helps to usher in a new age for the krogan, but if it was destroyed, then she dies trying to finish the cure, an outcome that's only made worse if the Urdnot clan leader is Wreav instead of Wrex.
* Magma Dragoon plays a huge role in Zero's CharacterDevelopment throughout the ''VideoGame/MegaManX'' series despite just being a Maverick boss who only sticks around for one game. He's the one who destroyed Sky Lagoon in ''VideoGame/MegaManX4'', the event which sparked the civil war between the Maverick Hunters and Repliforce and eventually led to Iris' death at Zero's hands, which haunts him even after the game. The Repliforce incident is also the first instance of the Maverick label being used against a group of uninfected Reploids, eventually leading to the term Maverick being used as a [=McCarthyist=] label to mark dissidents for execution in ''VideoGame/MegaManZero''.
** Passy, a Cyber-Elf in ''VideoGame/MegaManZero'' who [[HeroicSacrifice sacrifices herself]] to revive and restore Zero at the very beginning of the series, and is never mentioned again. However, if it weren't for her, Ciel would've been killed by the approaching Neo Arcadian forces and that would've been the end of the Resistance.
* In the ''VideoGame/MetalGear'' franchise, it turns out that [[spoiler:the members of Naked Snake's support team]] in ''VideoGame/MetalGearSolid3'' would become the founders of [[GovernmentConspiracy the Patriots]]. Additionally, Aleksandr Leonovitch Granin, the Russian scientist whom Naked Snake had been tasked with extracting as part of the Virtuous Mission, was the man who created the concept of the Metal Gear bipedal tank.
* The Mars People in ''VideoGame/MetalSlug 2/X'' would've wiped out both the P.F. squad ''and'' the Rebel Army with one blast of their WaveMotionGun if it weren't for the HeroicSacrifice of a random Rebel Army RedShirt crashing his plane into it in a ShoutOut to ''Film/IndependenceDay''.
* [[spoiler: Quiet Robe]] is this for his single speaking role in ''VideoGame/MetroidDread'' where [[ExpositionDump he drops a huge bombshell]] in regards to what happened to his tribe and why the Metroids became a massive problem for the entire series. [[spoiler: Quiet Robe's tribe wanted to blow up planet [=SR388=] to destroy the Metroids (and by extension, the X Parasites) since they couldn't be fully controlled and could put the galaxy in danger if they got out, but Raven Beak and his tribe wanted to use the Metroids as a weapon, thus they killed off Quiet Robe's entire tribe and kidnapped him so that they could learn how to control and produce the Metroids. The living Metroids were eventually found by the Galactic Federation and shortly thereafter stolen by the Space Pirates, which set off the first game in the series and all the trials thereafter.]]
* The Worried Mother in ''VideoGame/{{Miitopia}}''. Being one of three Greenhorne residents who didn't get their faces stolen by the Dark Lord, this allows her to give the hero the antique charm which releases a guardian spirit who bestows the hero the power to vanquish evil, kicking off the plot of the game.
* ''VideoGame/{{MOTHER}}'':
** In ''VideoGame/EarthboundBeginnings'', the plot kicks off years before the start of the game as the protagonist's grandfather stole knowledge of PSI from the species of the alien he and his wife adopted. George is dead by the time the game begins, and makes no appearance whatsoever. In fact, every single thing that goes wrong in the ''entire series'' can be traced back to George, up to and including [[spoiler:humanity's eventual destruction]].
** In the sequel, ''VideoGame/EarthBound'', the protagonist is visited by a bee (or not) from the future that starts up the plot of the game, is unceremoniously killed off moments later, and doesn't appear again until the credits.
** In ''VideoGame/MOTHER3'', Hinawa, Lucas and Claus' mother, is only seen in the prologue of the game [[spoiler:then dies offscreen during Chapter 1. Even so, [[TheLostLenore she has a big impact in the story afterward]], since she later saves Lucas' life through her father's dreams, then helps bring Claus to his senses despite him being robotically controlled.]]
* ''VideoGame/NierAutomata'': The aliens may not appear in the game [[spoiler: due to being wiped out by their own machines]], but their invasion of Earth caused 14 Machine Wars against the androids, [[spoiler: the Terminals they created to monitor the Machines slowly growing beyond their programming to "destroy the enemy" eventually perpetuating the war just to have a purpose. The aliens are also the reason the [=YoRHa=] androids ''exist at all'', because their consciousness is copied from their machine lifeforms, by the original androids left by humanity due to them being disposable.]]
* ''VideoGame/PAYDAY2'' has Hoxton, one of the characters from the first game, thrown in jail after being caught by the FBI. Nobody knows who ratted him out until the Hoxton Revenge heist comes into play. [[spoiler: Said rat turns out to be Hector, who is just a contractor for the PAYDAY gang that offered jobs for money and is nothing more beyond that. Hector worked with the gang without any of them knowing that he was the one that got Hoxton caught by the police. The crew winds up having to do a few jobs for The Dentist, who has information and power to help the crew get Hoxton out of jail. After the events of the Hoxton Breakout heist where the crew frees Hoxton, they go over the FBI server they stole and find out where Hector is hiding. Once the crew discovers that Hector is the traitor, they waste no time killing him and [[MissionControl Bain]] is shocked to see that someone unassuming like Hector was the one that ratted out Hoxton. Hector's actions caused the crew dynamic to be changed since they had to replace Hoxton with Houston and they had to jump through a lot of hoops just to get Hoxton freed.]]
* ''Franchise/{{Persona}}'':
** In ''VideoGame/Persona4'', Mayumi Yamano's presence has a huge impact on two antagonists the Investigation Team encounters. [[spoiler: Namatame]] is motivated to "save" the other victims due to Yamano's death and [[spoiler: Adachi]] discovers the ability to travel through the television after pushing Yamano into a TV during a confrontation.
** ''VideoGame/Persona5'':
*** Shiho Suzui. She's the best friend of Ann and a member of the Shujin Academy's volleyball club, meaning she's under [[spoiler:Kamoshida's abusive thumb. And outside of a few lines to the protagonist, she has no real connection. However, when the physical and sexual abuse of Kamoshida's gets too much for her, her attempted suicide ends up sparking the Phantom Thieves of Heart to be created. Before, the protagonist and Ryuji were hesitant to steal Kamoshida's heart, too worried of the potentially lethal consequences messing with a person's inner cognitive might do. But her attempted suicide shows them the ramifications of letting Kamoshida continue on, and it drives Ann to follow the protagonist and Ryuji into the Metaverse, gaining her own Persona, and making things [[ItsPersonal personal]] for all three members.]] Shiho started to roll the ball, though she remains in a coma for months after and only has a small cameo in Ann's Rank 9 Confidant event.
*** Suguru Kamoshida. The first target of the Phantom Thieves of Heart and basically a StarterVillain for them. Unlike later targets, he has no connection to the Conspiracy and only gets seriously targeted when the above [[spoiler:Shiho's actions make things personal for the initial party members. However, it's Kamoshida's change of heart that shows the Phantom Thieves that their methods work, and tip off the principal that the Phantom Thieves of Heart actually exist. This causes him to discuss things with the Conspiracy and eventually make Makoto Niijima try to find out the thieves' identities, leading to Makoto becoming a Phantom Thief herself, and further plot events occurring.]]
*** Ichiryusai Madarame. Beyond being the second target and his [[ItsPersonal personal]] connection being with Yusuke, Madarame is quickly forgotten. However, he is the one to [[spoiler: first mention a second Metaverse user in the form of the Black Mask, letting the party know that they aren't the only Persona users around and getting a hint towards the real reason behind the Mental Breakdowns occurring]].
*** Natsuhiko Nakanohara. Introduced as a stalker and introductory target for Mementos, [[spoiler:he turns out to lead the Phantom Thieves further down their path. He mentions Madarame, who turns out to be their next big target, and gives them a connection to their next team member in Yusuke. Once again, his prodding leads to Madarame becoming a personal target.]]
*** Wakaba Isshiki. As little as her role is in being Futaba's deceased mother and Sojiro's former friend-implied-love-interest, her handprint is all over the background plot. Wakaba was a researcher and was focusing on learning about Cognition, eventually leading her to find out about the Metaverse, Cognitive Dissonance and similar. Her research and knowledge in this [[spoiler:allowed Shido to realize how he can use the Metaverse and Cognition to his personal advantages. He chose to have her killed, making it look like an accident/suicide, and stole her research to use Mental Breakdowns to further his plans of becoming the next Prime Minister]].
* ''VideoGame/PokemonSunAndMoon'' has Mohn, caretaker of the Poké Pelago islands. He's [[spoiler:heavily implied to be the former Aether Foundation president and [[BigBad Lusamine]]'s husband, who disappeared in an Ultra Wormhole years ago and was never seen again. His disappearance turned his wife into a sociopath gone cuckoo for Ultra Beasts, and thus [[UnwittingInstigatorOfDoom several years of child abuse and the entire plot of the game happens as a result]]]]. And yet you'll never see him outside of Poké Pelago, which is an entirely optional feature. ''VideoGame/PokemonUltraSunAndUltraMoon'' confirms the spoilers, [[spoiler:and has the two reunite, albeit with Mohn having no memory of Lusamine because of his going through the Ultra Wormhole.]]
* ''VideoGame/Psychonauts2'' has Dr. Jack Potts. He was Hollis Forsythe's former boss at the hospital she worked at, and he was a jackass who stole her research methods and patented them as his own. He's never seen in person but the "Breaking Dr. Potts" memory vault reveals that Hollis accidentally messed with his mind and broke him, leading her to have to call the Psychonauts when Potts starts running around the hospital in his underwear. Truman comes to help mend Potts' mind and offers a regretful Hollis a job as a Psychonaut. The rest, as they say, is history.
* ''VideoGame/PunchOut'' has Aran Ryan's mother. She's barely even a BitCharacter[[note]]she is TheGhost, only being mentioned in [[AllThereInTheManual the manual]] for ''Super Punch-Out!!''[[/note]], but her stubbornness on spelling her son's name in an untraditional fashion sparked a [[ForWantOfANail chain]] [[AllOfTheOtherReindeer of]] [[UsedToBeASweetKid events]] that led to present-day Aran Ryan being a borderline criminal BloodKnight.
* A character who's only ever brought up three times ([[spoiler:once while fishing with Jack, once to either Reverend Swanson or Sister Calderon, and once to Rains Fall]]) in the course of the game plays a huge part in explaining many of Arthur Morgan's decisions in ''VideoGame/RedDeadRedemption2'', [[spoiler: his deceased son Isaac. He died at an unspecified point before the events of the game but his death hardened Arthur and explains much of his self-loathing. He believes that Isaac dying was his karma for his choices in life. It also explains why he's still so resentful of John for his treatment of Jack. It's also why he decides to sacrifice himself to give John a chance at a normal life with Jack and Abigail. He wanted John to have what he couldn't.]]
** Dutch van der Linde murders a young woman by the name of Heidi [=McCourt=] in cold blood in the botched Blackwater ferry job that happened right before the beginning of the game. Allegedly, the job was going well until he was goaded into killing her by Micah. This got the law on their tail and made them stash the take (worth over $4 million today when adjusted for inflation) which was enough for them all two dozen or so of them to retire from the outlaw life. It was their OneLastJob. The law follows them for the rest of the game and Dutch comes up with increasingly erratic plans to replace the take with another last big score, including picking a fight with the US Army. The botched job is essentially the noose around the whole gang’s necks. Had he not killed her, the events of both this and the [[VideoGame/RedDeadRedemption first]] game wouldn’t have happened at all. She's so important to the story that a strange man John meets in ''I'' who's implied to be {{God}}, TheDevil, or the incarnation of death brings her up.
** Thomas Downes dies about a third of the way through Chapter 2, but he [[spoiler:gives Arthur tuberculosis, eventually resulting in the latter's death]].
** Molly has limited screen time but [[spoiler: her death]] establishes two things that end up sealing the fate of the Van der Linde gang. First, Arthur asking Dutch [[spoiler: to spare her despite the gang's rules about traitors]] convinces Dutch to isolate himself from his adopted son. Then, because Molly [[spoiler: drunkenly claimed she was the traitor]], this helped [[spoiler: the real traitor Micah stay safe]].
* ''Franchise/ResidentEvil'' has a few:
** ''VideoGame/ResidentEvil'' happens because helicopter pilot Brad [[ScrewThisImOuttaHere gets spooked by a group of zombie dogs and flies away]], abandoning the rest of the S.T.A.R.S. team as they're forced to seek shelter at a nearby mansion that is filled with monsters and traps. He doesn't appear again until at the end of the game where he comes back to rescue the remainder of the team.
** A group of Umbrella soldiers in ''VideoGame/ResidentEvil2'' appear for a small scene in a flashback where they wind up nearly killing William Birkin for his G-Virus sample. Birkin is NotQuiteDead and uses his G-Virus on himself, transforming himself into a monster as he gets revenge on the soldiers and spreads the virus to the whole city via rats ingesting the spilled virus samples dropped by a soldier.
* In ''VideoGame/SoulCaliburVI'', [[Franchise/TheWitcher Geralt of Rivia]] is a GuestFighter whose story mode is him trying to get back home, pointedly ignoring the struggles of the strange world he finds himself in. However, his story is canon, and his encounters with native characters Mitsurugi and Zasalamel have a significant impact on the CharacterDevelopment of both.
** Mitsurugi is still stinging from his losses to Geralt, and Geralt's [[UnknownRival dismissal of him]], ''three years'' after Geralt's return to his own world, listing him by name as one of the very few {{Worthy Opponent}}s he has faced.
** Zasalamel helps Geralt return home, and also states that he'll be considering the existence of other universes like Geralt's in his [[TheChessmaster future schemes]].
* First Lieutenant [=McPherson=] of the Damned 33rd, from ''VideoGame/SpecOpsTheLine''. Because of him, Walker decides to buck orders and turn Delta Squad's recon mission into a rescue op. And when they actually find him...
* High Templar Karass of ''VideoGame/StarcraftII'' fame. He and his men meet up with Zeratul, help him fight through the zerg, and then he and his remaining troops pull a LastStand HeroicSacrifice to allow Zeratul to escape. Yet those few minutes, he and his men might have saved the universe.
* ''VideoGame/StarStealingPrince'': Lorel, the first boss, only shows up for that boss fight and a HopelessBossFight beforehand. It's essentially a wild creature unconnected to any other antagonists or the overall plot. Then ''Literature/EphemeralPrince'' reveals that [[spoiler:Snowe ''died'' in that HopelessBossFight and is only "alive" because of Xiri's magic]].
* The heroes of ''VideoGame/TheSubspaceEmissary'' would never have been able to defeat [[spoiler:Tabuu if Sonic hadn't damaged his wings at the last minute to weaken him]].
* The crew of the [[PrisonShip UMS Vortex Rikers]] in ''VideoGame/{{Unreal|I}}'': They only appear as dead corpses whose logs you could read in the early levels, but if their ship wasn't caught in the magnetic field of planet Na Pali, Prisoner 849 wouldn't have gone FromNobodyToNightmare, the Skaarj Queen and her Warlords wouldn't have been slaughtered, the Nali wouldn't have escaped from being a meek slave race into an uprising, the Skaarj wouldn't have been interested in humanity and their discoveries, the Seven Years War and humanity's near extinction would never took place, and most important of them all, the Terran Colonial Authority and the New Earth Government wouldn't have been formed, and the legendary Liandri Grand Tournament would have never existed.
** Also to a lesser extent, [=FenTech=] Incorporated. Their small role? They were only mentioned in ''VideoGame/UnrealTournament'', and in only two separate bios from two players from separate teams who were created by them. Their big impact? One of said players is [[LivingLegend Malcolm]], a chemical killer who went on to lead [[BadassArmy Thunder Crash]], dethrone corrupt champion [[TheDreaded Xan Kriegor]] and dominate the Liandri Grand Tournament for almost a decade. And that's just InUniverse, as Malcolm also became the SeriesMascot.
* Grand Marshall Garithos from ''[[VideoGame/{{Warcraft}} Warcraft III]]'' posthumously became this once certain events in ''VideoGame/WorldOfWarcraft'' transpired. His fantastic racism was one of the key factors that drove the Blood Elves from the Alliance, causing a small number of them to join will AntiVillain Illidan Stormrage, and the rest to eventually side with the Horde. To a much lesser extent, he helped Sylvannas Windrunner retake the capital of Lordaeron, which led to it being taken by the Forsaken, though in this case Sylvannas actually promised to hand the city over to him and [[ILied betrayed him]] [[YouHaveOutlivedYourUsefulness when she was done using him]].
** Thrall's adoptive human sister, Taretha Foxton, appears in a grand total of one ''[[Literature/LordOfTheClans Warcraft]]'' book and no games, but her influence on BigGood Thrall and his philosophies can't be overstated. Her kindness and UndyingLoyalty proved that friendship and trust could exist between humans and orcs, something that Thrall continued to fiercely believe in throughout his entire life. [[CrapsackWorld Azeroth]] and [[BadassArmy the Horde]] would've turned out very, ''very'' differently if Taretha hadn't shown Thrall so much compassion and love in his formative years.
* In ''VideoGame/TheWarriors'', Ash is a new recruit to the Warriors gang, but he's basically a FlatCharacter serving as a player 2 (or another generic gang member if you are playing solo) and doesn't evolve beyond that. He gets killed off screen by the rival gang, the Destroyers, and his death kick starts a climactic showdown between the two gangs.
* The Ghosts in ''VideoGame/XenobladeChroniclesX'' only appear in the opening cutscene as one side in the war that destroys Earth and later as the side that attacks the White Whale, causing it to crash on Mira. Pretty much none of the plot would happen without them, but they aren't even named in the game with the name "Ghost" comming from [[AllThereInTheManual the game's Japanese artbook]].
* ''VideoGame/YandereSimulator'':
** MagicalGirl Pretty Miyuki may only be the title character of a ShowWithinAShow, but the fact that the first rival, Osana Najimi, bears a strong resemblance to her is critical in her story arc, as it attracts her a StalkerWithACrush LoonyFan that kidnaps her cat in order to lure Osana to his house, and Yan-chan has the option to rescue the cat in order to win Osana's trust enough to ask her to leave Senpai for Yan-chan, or kidnap Osana herself.
** By the time the story begins, Ichiko [[spoiler:Saikou]] had been estranged from her family for three decades, and is WanderingTheEarth, but Akademi would not even ''exist'' if it weren't for her, and her abandoning her family had massive ramifications for her younger brother, niece, and nephew.
** Sumire Saitozaki exists to serve as the tutorial in [[{{Prequel}} 1980s Mode]], but her death [[spoiler: is what catches The Journalist's eye and causes him to investigate-and eventually arrest-Ryoba, leading to the trial that discredits him as a journalist, exonerates Ryoba, and forces her to kidnap her Senpai rather than confess under the sakura tree.]]
[[/folder]]

[[folder:Visual Novels]]
* ''Franchise/AceAttorney'':
** The murderer of [[SpiritAdvisor Mia Fey]], [[ReverseWhodunnit Redd]] [[CorruptCorporateExecutive White]], is an example of a character's role being relatively small ''because'' of their large impact. [[FirstEpisodeTwist You wouldn't want to spoil the ending of one of the first cases in the series for people playing out of order, would you?]]
** Doug Swallow from ''Trials and Tribulations''. He's a victim of a tutorial case in the third game with just a few seconds of screentime. But his attempt to warn Phoenix about Dahlia is what not only saved Phoenix from Dahlia and lead to her arrest but also to Phoenix meeting Mia and becoming her apprentice which in turn made him responsible for a significant part of the original trilogy.
** Yutaka Kazami (Dane Gustavia in the Fan Translation) from ''Ace Attorney Investigations 2''. Looking at just that game, [[spoiler:abandoning his son was the first step in his son's transformation to a sociopath and the BigBad of the game]]. He's also one of the few characters from the ''Investigations'' duology to have a major impact on the franchise as a whole: [[spoiler:He was the murderer in Gregory Edgeworth's final case, which led to [[TokenMotivationalNemesis Manfred von Karma]] getting a penalty and killing Edgeworth for revenge. This was the starting point of the franchise, with every major character from the original trilogy being motivated by von Karma's actions in some way]].
*** His victim, Isaku Hyoudou (Isaac Dover in the fan translation) has an even smaller role, but a slightly bigger impact. [[spoiler:We never see him alive in the present, but his betrayal and attempted blackmail of Gustavia is what made him commit murder, kickstarting the events of the plot of the whole series, and his kidnapping of Dover's son is what causes the events of ''Investigations 2'' to happen.]]
** With Bansai Ichiyanagi (Blaise Debeste in the fan translation) being who he is, namely the chairman of the PIC, it's hard to think of a point in the entire series that ''didn't'' play out the way it did because of him.
** Grimesby Roylott/[[spoiler:Nikolina Pavlova]] only appears in one case of ''VisualNovel/TheGreatAceAttorney'', but has a great impact on the course of the story [[spoiler:She accidentally pushes Kazuma and seemingly kills him, resulting in Ryunosuke taking his place as a defense attorney. This would seem like a large enough impact, but it later turns out that Kazuma had agreed to come to Japan in order to assassinate Inspector Gregson, and the fact that Ryunosuke had no knowledge of the plan, let alone the willingness to carry it out, forced Seishiro Jigoku to personally kill Gregson in the final case, resulting in Ryunosuke exposing Jigoku as a murderer and unraveling the Reaper conspiracy.]]
* ''VisualNovel/DanganronpaTriggerHappyHavoc'' has [[spoiler:Chihiro Fujisaki]]. While [[spoiler:he quickly dies, becoming the victim of the second case, effectively the 4th death of the game, it turns out that he used the old laptop the group found in the library to create an AI of his image that can hack and collect information inside the network of the school, eventually saving Makoto's life from his execution and helping the group to get out of the school. By the second game, it turns out he was the one that developed the Neo World Program, as well as setting up the basis for the AI Chiaki that helped Hinata]].
* In ''VisualNovel/ShiningSongStarnova'', the creepy stalker Reon appears for a single scene halfway through Julie’s route, where [[spoiler:he attempts to murder her in broad daylight during a public handshake event]]. While the police promptly arrest him, his actions leave Julie with physical and psychological scars and Starnova in dire financial straights for the remainder of the route.
* In ''VisualNovel/SpiritHunterNG'', Yuri's only role is as the tutorial boss, and she doesn't get much development beyond her bond with Ami and Kaoru -- however, it's that bond that causes Ami, and by extension, the protagonist Akira, to get involved with [[BigBad Kakuya's]] game.
* ''VisualNovel/UminekoWhenTheyCry'' has Beatrice [[spoiler:Castiglioni]]; she only appears in Kinzo's flashbacks during the seventh arc, but Kinzo's relationship with her and [[spoiler:her later DeathByChildbirth]] have a huge impact on the plot.
[[/folder]]

[[folder:Webcomics]]
* ''Webcomic/ElGoonishShive'':
** [[spoiler: Blaike Raven]] appears in [[http://egscomics.com/comic/2016-07-08 only]] [[http://egscomics.com/comic/2016-07-11 three]] [[http://egscomics.com/comic/2016-07-13 strips]] of the entire comic, 14 years into its run, but his death is the reason Pandora did not reset for centuries and stayed close to her elf son both of which is highly unusual for an Immortal who typically reset every couple centuries and relatively quickly forget they even have descendants. He is also responsible for the existence of Adrian Raven, a major supporting character.
** The original Grace Sciuridae appears in [[http://egscomics.com/comic/2003-10-10 one panel]] but is responsible through her PlotTriggeringDeath for the existence of the main universe's Grace being what she is instead of a hulking male like [[http://egscomics.com/comic/2004-03-12 General Shade Tail]].
* The Muse of Time/Mysterious Entity from ''Webcomic/GirlGenius''. In her [[spoiler:first]] appearance she spooked Agatha, causing her to run into the alley where her locket was stolen, kicking off the plot.
* Feferi of ''Webcomic/{{Homestuck}}''. In the alpha timeline, she doesn't get up to much, aside from [[spoiler: establishing the dreambubbles by using her connection with the Noble Circle of Horrorterrors.]] The Feferis from other timelines are implied to have had a much bigger impact on their timelines, with one even ascending to God Tier, but aside from that, she's a minor character.
* ''Webcomic/{{Nebula}}'': Ceres appears for only two comics and has [[TheUnintelligible no intelligible dialog]] at all, but through their actions ends up changing the status quo massively enough that afterwards NothingIsTheSameAnymore.
* ''Webcomic/TheOrderOfTheStick'':
** Fyron Pucebuckle ([[SeriesContinuityError and his son?]]). Technically, Roy is trying to avenge his/their death(s), despite having never met him/them. Fyron was his father Eugene's mentor before being killed by [[BigBad Xykon]]; Eugene swore a Blood Oath of Vengeance, and after he died (of natural causes), Roy took up the duty to continue it. The thing is, in the process he discovered that Xykon is threatening the whole cosmos, so by now Fyron's death is sort of an afterthought. (Fyron himself only gets any characterization in [[StartOfDarkness Xykon's origin story]].)
** There's also Kraagor, one of the members of [[PrecursorHeroes The Order of the Scribble]]. He has had only three lines and three appearances within the story. However, his death contributed to The Order of the Scribble falling apart, and the making of the Gates.
** There's also the Black Dragon teenager, who guarded the cave that contained the starmetal. [[spoiler:While he only appears for a few strips in what seems like a relatively minor story arc, [[MamaBear his mother]] comes back to avenge him by attempting to kill Vaarsuvius' children. Vaarsuvius' actions from that point onward have [[DealWithTheDevil very]] [[FamilyExtermination drastic]] [[HeroicBSOD consequences]].]]
** Fenris is responsible for the creation of the goblinoid races in the first place, making him one of the most important gods in the entire comic's backstory, yet his only appearances in the story are when his High Priest summons him at the Godsmoot and when Thor casts a brief illusion of him.
** Dvalin isn't in the comic much, but his decision not to vote without the advice of the Dwarven clans changes Hel and the Order's plans and sets up the final confrontation between the High Priest of Hel and the Order.
** Jiminy, Haley's cousin, only makes two very brief appearances, [[spoiler: but it's only because Geoff exchanged both his and Ian's freedom in exchange for Jiminy's that Ian and Geoff have been stuck in the Empire of Blood's prison for so long, instead of having to fight in the arena]].
* In ''Webcomic/SpringTrapped'', the [[VideoGame/FiveNightsAtFreddys3 Fazbear's Fright Guard]]. He is never seen, and only figures into the first page and a flashback, but he's the one who destroyed Springtrap for good when he burnt down the Fright, which sent the Purple Guy into his afterlife (''VideoGame/FiveNightsAtFreddysWorld''), which is where the story proper takes place.
* ''Webcomic/StandStillStaySilent'':
** A couple of troll-inflicted injuries have a long-term impact on the story, while the trolls that inflicted them were killed within a chapter of being introduced.
** Torbjörn's boss, who only appeared in a flash-back. He's the one who informed Torbjörn of just how valuable Old World books were, and made him realize how much money he could make by getting his hands on some and selling them.
** Ensi Hotakainen, in Adventure I. To quote Onni during Lalli's MyGreatestFailure flash-back:
--->'''Onni:''' Grandma made one mistake, and see where that got us.
* ''Webcomic/WeakHero'':
** Hugo Yoon is less than a two-bit thug, but he's also the one responsible for the hero's iconic "White Mamba" title, which in turn leads the Yeongdeungpo Union to take him seriously -- a fact that Hugo is quick to brag about.
** Though Kenny only has prominence in a single flashback, his actions in the past proved very important to the establishment of the Yeongdeungpo Union. He tried to leave the Manwol Gang to protect his brother, which in turn caused the Manwol to inflict a CareerEndingInjury on him. This spurs his brother Jake to seek revenge, which in turn causes him to join the Union, which in turn gives [[BigBad Donald]] the excuse he needs to obliterate the Manwol and establish the Union as the strongest gang in the city.
[[/folder]]

[[folder:Web Videos]]
* The second campaign of ''WebVideo/CriticalRole'' kills off [[spoiler:Mollymauk]] surprisingly early; but his presence is felt for the rest of the story, from changing some of the team's morals to [[spoiler:having his backstory play a huge part in the final arc]].
* ''WebAnimation/MinilifeTV'': In "[[Recap/MinilifeTVSeason3Episode2 That's So Gay!]]", two particularly rude characters who only have a few seconds of screentime make homophobic remarks about Chris and Ian's gay friend, Todd, which drive Chris and Ian to turn the titular phrase into a positive statement.
* ''Machinima/RedVsBlue'' has [[AmbitionIsEvil Sigma]]. He only appears in a few flashbacks in Season 10 (and died at the end of Season 6), but he's TheManBehindTheMan for the Meta, who is ultimately the reason the plot got anywhere outside of Blood Gulch.
** There's also Captain Butch Flowers. He appears in a couple scenes in ''The Blood Gulch Chronicles'' and gets killed off pretty quickly, but he's the ''actual'' commander of the Blues, and his pre-series death is the reason why Church is in charge (and why Tucker has cyan armor -- it was once his). [[spoiler: And he's Agent Florida, who was set to watch over the Alpha AI, and he accidentally allowed the entire series to happen by scrambling the list of people who were to be sent in his place if he died. This is what sent Caboose, Donut, and (later on) Sister to Blood Gulch, which resulted in Tex showing up, and with her [[CardCarryingVillain O]][[AIIsACrapshoot 'Malley]], which lead to the entire plot of ''The Blood Gulch Chronicles''.]]
* {{LetsPlay/Skawo}}'s Playthrough of VideoGame/MarioAndLuigiDreamTeam is the first appearance of the [[ViewersAreGoldfish Orly?! Counter]]. While it was intended to be a one off, it just stuck, while the playthrough itself did not, and now it appears in almost every playthrough.
* In the ''WebVideo/SuperMarioLogan'' series, both regular [[ShowWithinAShow Show Within a Shows]], ''[[ProtagonistAndFriends Charleyyy and Friends]]'' and ''Doofy the Dragon'' are responsible for a few major plot elements. Such examples include "[[BabysittingEpisode Black Yoshi's Job]]", where Bowser [[{{Hypochondria}} thinks he has chicken pox]] after seeing a ''Charleyyy and Friends'' episode where Charleyyy has the aforementioned disease, and "Bowser's House Fire", where Bowser Junior sees a ''Doofy'' episode where Doofy lights himself on fire. This causes Junior to think it would cool to start a fire, and light a candle. When he, Bowser, and Chef Pee Pee get back from [=McDonald's=], they find out their house has burned down, and [[NiceJobBreakingItHero the candle was the cause of the fire]].
* ''WebAnimation/HelluvaBoss'': Deerie only gets a small amount of screentime during a scene near the very end of episode 4, but said scene provides strong implications that [[GodAndSatanAreBothJerks Heaven isn't much better than Hell in this universe]], which has [[InherentInTheSystem major potential ramifications]] for not just this series, but also the very plot of ''WebAnimation/HazbinHotel''.
[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/TheAmazingWorldOfGumball'': The Van Shoopkeeper didn't appear after Season 4 (and got mentioned in Season 3), and has made only five appearances so far, but he's the reason Darwin (the main character along with Gumball) got adopted by the Watterson family.
* ''WesternAnimation/AvatarTheLastAirbender'':
** Fire Lord Sozin was the one who started the war and Fire Lord Azulon probably did the most damage during said war, both were dead before the start of the series and got one flashback episode each, but otherwise are only occasionally mentioned.
** The past Avatars as well, most notably Roku and Kyoshi.
** The monks in the Southern Air Temple who tried to kickstart Aang's Avatar training in his flashbacks. It was only due to their (rightful) fears that the above-mentioned Sozin was about to start a war that Aang prematurely learned he was the Avatar, and ran away from the Air Temple not being able to handle the subsequent stress. He inadvertently saved himself from the Air Nomad Genocide that Sozin committed ''specifically'' to kill him, meaning if the monks hadn't intervened, Aang would have been killed at the Southern Air Temple and the subsequent Water Tribe Avatar would have had a ''hell'' of a time learning (let alone mastering) Airbending.
** Iroh’s son Lu Ten died about a decade before the show began and is only seen in pictures but his impact on the show is huge. With no direct heir left, Ozai asks their father Azulon to forgo Iroh’s birthright and let him be the Fire Lord. Azulon is incredulous about him kicking his brother while he’s down and orders Ozai to lose his oldest son. Ursa works out a deal with Ozai that she’ll poison Azulon to save Zuko’s life which in turn makes Ozai the Fire Lord and leads to both Ursa and Zuko’s banishments. He's also the reason Iroh gives up his seige of Ba Sing Se. Had Lu Ten not died, Iroh might have won the war for the Fire Nation and left Aang without a world to save.
** Much of Zuko's story and character arc is caused by his clash with the Fire Nation general in that ill-fated council meeting, who suggests using inexperienced rookie soldiers as cannon fodder. If Zuko (who wasn't even supposed to be attending the council until Iroh agreed to bring him along) hadn't spoken up to rebuke the general and been challenged to an Agni Kai, his injuries, dishonour and banishment would likely never have happened, and in turn ''so much'' of the story would have been completely different.
** If Katara and Sokka's mom Kya hadn't pretended to be the last waterbender to save Katara, Katara would have died and wouldn't have been able to get Aang out of the iceberg.
* ''WesternAnimation/BojackHorseman'':
** IntrepidReporter Paige Sinclair only appears in five episodes in the final season, but it's her investigation into the circumstances behind [[spoiler: Sarah Lynn's death]] that set the final arc into motion and results in her exposing Bojack's dirty secrets and misdeeds, particularly [[spoiler: that his MurderByInaction was responsible for Sarah Lynn's death by overdose.]]
** Likewise, her partner in journalism, Maximilian Banks, appears in one less episode than her, but it's his comment that he's taking calls from [[spoiler: Sarah Lynn's mother]] that piques Paige's interest and causes her to delay her [[QuittingToGetMarried wedding and resignation]] to investigate.
** Network executive Angela Diaz appears in one early flashback and then appears properly in one episode in the final season. That flashback had her convince [=BoJack=] to abandon his friend Herb Kazzaz after Herb was fired from their show for being gay. Not only did this ruin [=BoJack=] and Herb's friendship, it started [=BoJack=] down the path of prioritizing his career and his celebrity status over his relationships and the wellbeing of others, leading him to become the jaded, cynical washout he starts the series as.
*** Taking it one step further, Angela's flashback in season six shows that her conversation with [=BoJack=] was prompted by an encounter with a group of unnamed male collegues who excluded her from the Boys' Club at the network. Her desperation not to be left behind is what prompted her to play hardball with [=BoJack=] in order to save the show in the first place.
** [=BoJack's=] long-deceased uncle, [=CrackerJack=], who only appears in one flashback, ends up indirectly kicking off multiple generations of familial trauma when he's killed in World War II. His mother goes mad with grief, and her husband, rather than deal with it, has [[spoiler:her lobotomized]], which traumatizes Beatrice and results in her never holding strong emotional attachments later in life, which culminates in her horrible treatment of her son [=BoJack=].
* ''WesternAnimation/DannyPhantom'':
** Walker only appears as an antagonist three times, but he's responsible for 1) making Danny a HeroWithBadPublicity from "Public Enemies" until the events of "Reign Storm", and 2) for [[BrokenMasquerade the human public now knowing that ghosts really do exist.]]
** Freakshow might have been one, had it not been for StatusQuoIsGod. In his second (and last) appearance, he's responsible for revealing Danny's secret identity to everyone, including Danny's parents. However, after defeating Freakshow, Danny pushed the ResetButton on everything.
* Ms. Manson in ''WesternAnimation/{{Daria}}.'' She only speaks in the first episode and rarely even cameos, but her decision to send Daria to the Self-Esteem Class (possibly more due to personal dislike than actually thinking Daria needed it) was what ultimately caused Daria and Jane's friendship.
* ''WesternAnimation/DuckTales2017''
** May and June only appear in the GrandFinale, but it's the fact that they even ''exist'' that has Webby question her origins, leading to her finding out who she really is: [[spoiler: namely, Scrooge's OppositeSexClone-slash-technical biological daughter.]]
** Isabella Finch is possibly the biggest example within the series. Not only is she Scrooge's idol and one his main motivations for adventuring, not only is she the founder of the Junior Woodchucks, not only is her journal -- the original Junior Woodchuck Guidebook -- used a GreatBigBookOfEverything throughout Season 3... but she also turns out to be Bradford Buzzard's grandmother and an indirect catalyst for Bradford being tramatized by adventure and wanting to wipe it out as he grew up, and ruin Scrooge's life and tear his family apart, and overall morph into the show's GreaterScopeVillain. In other words, pretty much any major event within the series is because of her. Not bad for a character that only appears in the final season, and only on photographs, and in brief flashbacks, and conversations.
* In ''WesternAnimation/ElenaOfAvalor'', Elena's cousin Duke Cristobal counts for this. His only major appearance is in "Song Of The Sirenas", where [[spoiler: Elena kills Shuriki, the Delgados go on the run where they eventually run into Ash a few episodes later, and Elena's scepter starts malfunctioning (eventually leading her to giving it to the Sunbirds before getting it back in Season 3 and it falling into the crystal well of Takiana and gaining new magic powers).]] Who knew he would leave an impact?
* The ''WesternAnimation/FairlyOddParents'' episode "The Secret Life of Denzel Crocker" reveals that, as a child, Mr. Crocker had a babysitter named Vic whose abusive behaviour was the primary catalyst for Crocker gaining fairy godparents (the loss of said godparents acting as Crocker's StartOfDarkness). Vic is also strongly implied to be Vicky's father, meaning that -- by nature or nurture -- her own abusive tendencies likely stem from him. In other words, Vic -- who appears on-screen for about ten seconds -- is indirectly responsible for ''both'' of Timmy Turner's main arch-enemies, and by extension, indirectly responsible for Timmy himself gaining fairy godparents and kickstarting the entire series.
* ''WesternAnimation/HeyArnold'': In-universe example, as revealed in one of Grandpa Phil's wartime stories, he was basically a delivery boy for the Americans during the Western Front, tasked to supply Cham to the Allies. Unfortunately getting lost allowed the Nazis to capture him, but his own wit knowing how rancid the Cham was allowed him to trick his captors into eating it, causing mass food-poisoning and letting the Allies march into Belgium relatively unopposed and with it, winning The Battle of the Bulge. In other words, a clueless delivery-boy effectively ensured the Allies won World War II in Europe.
* ''WesternAnimation/TheJetsons'': The cat burglar who appeared in Astro's debut episode. He only appears in that episode but it's because of his attempt to rob the Jetsons that they decided to keep Astro instead of an "apartment approved electronic dog" as their pet.
* ''WesternAnimation/TheOwlHouse'' has an unnamed member of the Emperor's Coven who scheduled Lilith and Eda to duel each other in "Young Blood, Old Souls". He only appears for ten seconds in a flashback, yet every single event in the series can be traced back to them since if they hadn't done that one thing [[spoiler:Lilith wouldn't have cursed Eda to get an edge in the fight, which means that Eda wouldn't have found the Portal Door while running away from home out of fear of their mother's more extreme measures to cure her and Luz never would have been able to come to the Boiling Isles in the first place.]]
* ''WesternAnimation/RickAndMorty'': Weird Rick only appears in 2 scenes in 2 different seasons, but him killing [[spoiler: Beth and Diane C-137 eventually made Rick go into a RoaringRampageOfRevenge with him murdering hundreds of his versions, causing the formation of the Citadel and the Central Finite Curve by Rick. The Citadel will also manipulate Beth and Jerry across infinite timelines to get together and birth Morty and Summer, causing the existence of the Morty we are familiar with, and the depression of Rick eventually made him crash into the life of a Beth whose Rick actually abandoned him... causing the start of Season 1.]]
* ''WesternAnimation/ScoobyDooMysteryIncorporated'' has a few:
** Harlan Ellison. He appears in a grand total of ''two'' episodes (though he's referenced as [[PutOnABus being on vacation]] in a third), and the first [[InnocuouslyImportantEpisode doesn't appear to be particularly significant to the show's]] MythArc. The second? It's the show's [[GrandFinale series finale]], where he proves to be instrumental to resolving the plot. [[spoiler: After the kids rewrite reality by erasing the Evil Entity, Ellison turns out to be the only other person who remembers the old reality, thanks to his experiments in speculative fiction]]. The show then ends with [[spoiler: the kids accepting an invitation to travel to Miskatonic University, where Ellison works as a professor, and [[AndTheAdventureContinues planning to solve mysteries under him]] as the new "Mr. E"]].
** Danny Darrow. He only appears in the flesh in "Escape From Mystery Manor", but he also gives the gang the very first Planespheric Disc that they ever get their hands on. And much later, it's revealed that he's the lone surviving member of the Mystery Fellowship -- the direct predecessor to [[LegacyCharacter the first Mystery Incorporated.]] Danny's appearance gives us our first real idea of how long the mystery-solving organizations have ''really'' been around, and the story of his descent into madness gives us our first real glimpse of [[spoiler: the corrupting power of the Evil Entity.]] Even when Danny's not directly around, Darrow University is a major location in Crystal Cove, and the site of the collapsed Darrow Mansion is considered a major Crystal Cove landmark, reminding us of the Darrow family's enduring legacy. [[spoiler: He's important enough that we get to hear about his ultimate fate in the new timeline in the series finale, with the revelation that he grew up to be dean of Darrow College and turned his family's old mansion into a historic site.]]
** Abigail Gluck. She's a PosthumousCharacter, and only her corpse actually appears in the flesh. But she was also the EvilMentor to [[BigBad Professor Pericles,]] and her amoral teachings apparently led directly to his StartOfDarkness in his early days, and she was the original inventor of the fearsome Kriegstaffelbots that make up the bulk of Pericles' army after he recovers her old factory. Alongside Danny Darrow, she's one of just two characters from previous mystery-solving organizations (other than the first Mystery Inc.) to play a direct role in the series.
* ''WesternAnimation/StevenUniverse'':
** [[spoiler:Before being unbubbled permanently and being redeemed late in Season 5,]] [[UltimateBlacksmith Bismuth]] only properly appears in [[Recap/StevenUniverseS3E20Bismuth one episode]] in person and [[Recap/StevenUniverseS3E3SameOldWorld another]] [[Recap/StevenUniverseS5E13YourMotherAndMine two]] briefly in a flashback. Despite this, some of her actions have major consequences:
*** She was the one who [[spoiler:poofed [[WoobieDestroyerOfWorlds Lapis Lazuli,]] leading to her being imprisoned in a mirror for 5,000 years. Lapis' release halfway through Season 1 is the beginning of the MythArc.]]
*** In her self-titled episode, she tells Steven that, on Rose's request, she designed her sword so that it could only poof a Gem, never shatter. This is what makes him suspicious when [[spoiler:Blue Diamond yells at his trial that Rose used a sword to shatter Pink Diamond, and more so when the below-mentioned Defence Zircon points out other holes in the story. This ultimately leads to Steven concluding that someone else shattered Pink Diamond, and eventually to TheReveal that Rose ''was'' Pink.]]
** Blue Zircon only appears in [[Recap/StevenUniverseS5E2TheTrial one episode,]] but she reveals that the circumstances surrounding [[spoiler: the death of Pink Diamond]] don't make sense, and voices that the most likely culprit is not Rose Quartz, but ''[[DidYouJustFlipOffCthulhu one of the other Diamonds.]]'' She is then immediately [[DoNotTauntCthulhu poofed]] by Yellow Diamond. [[spoiler:Sure enough, it turns out one of the Diamonds ''did'' "kill" her -- Pink Diamond faked her own death to [[TwoAliasesOneCharacter fully take on her Rose Quartz identity.]]]]
** Greg's former manager Marty only appears in [[Recap/StevenUniverseS2E5StoryforSteven two]] [[Recap/StevenUniverseS3E7DropBeatDad episodes]] (with a brief cameo in [[Recap/StevenUniverseS3E8MrGreg a third]]), but if it weren't for him, Greg never would've stayed in Beach City, and thus Steven would've never been born. Later, his brief return to Beach City directly leads to Greg and Pearl ending the tension between them and Pearl finally getting over Rose's death.
* ''WesternAnimation/TeenageMutantNinjaTurtles2003'': The Y'Lyntians only make five appearances (two in person, two in flashbacks, and one in cocooned states), but their influence is felt in some way across all seven seasons. They originally built the heroes' lair as an observation post. Their presence plays a role in the two episodes of the Underground mutants arc where they don't actually appear. And each of their three former {{Slave Race}}s is the focus of an episode, and Raptarr from the third such race becomes a recurring character for the rest of the show.
* ''WesternAnimation/TheVentureBrothers'':Dr. Henry Killinger has only three major appearances (with bit roles in few others), but in each of those appearances, plays a significant role in shaping the Venture universe:
** His first appearance in Season 2's ''I Know Why the Caged Bird Kills'' has him rebuild the Monarch's organization and reunites him with Dr. Girlfriend. These events lead up to [[spoiler: their marriage at the end of Season 2]] and their evil-doing abilities have gone up a [[NotSoHarmlessVillain a few levels]] ever since.
** His second major appearance in Season 3's ''The Doctor is Sin'' has him attempt to do the same thing for Doctor Venture and Venture Industries, but ultimately serves to give Venture a [[spoiler:HeelRealization.]] Venture's {{Jerkass}} tendencies have been slightly lessened ever since, though he still falls into the JerkassWithAHeartOfGold category more often than not.
** His third appearance in the pre-Season 6 one-hour special ''All This and Gargantua-2'', has him helping to build up and expand the Revenge Society into a legitimate supervillain organization. [[spoiler: He also kills the Investors and saves the Guild of Calamitous Intent after the Sovereign tries to KillEmAll.]] It's a major shakeup in the Venture universe, to be sure.
[[/folder]]

** In [[VideoGame/MassEffect the first game]], it's because of a lazy dockworker named Powell who managed to survive the geth attack on Eden Prime by being asleep behind some dock crates that Shepard's team is able to learn about Saren Arterius going rogue, which results in Shepard being made the first human Spectre and going on to save the colony of Feros, uncovering the return of the rachni at Noveria, destroy a krogan cloing facility on Virmire, and ultimately discover the impending threat of the Reapers.
** In [[VideoGame/MassEffect2 the second game]], it's because of the medical officer Wilson [[spoiler:on orders from his benefactor the Shadow Broker]] sabotaging the systems at Lazarus station where Cerberus was putting the Commander back together after the destruction of the ''Normandy'', that pushed Miranda Lawson to wake Shepard up ahead of schedule, allowing the Commander to, among many things: cure the plague ravaging the slums of Omega, rescue the genetically perfect krogan Grunt from being destroyed or exploited, protect the remainder of the colonists on Horizon from capture, realize the origins of the mysterious Collectors [[spoiler:as heavily augmented Protheans controlled by the Reapers]], lay the seeds for a lasting peace between organics and synthetics by interacting with the geth called Legion, and ultimately eradicate the Collectors as a major threat to humanity ahead of the Reapers' coming invasion.

*** Argubaly, the salarian scientist named Maelon serves as one for both ''2'' and ''3''. He used to be a novice member of Mordin Solus' old research team that made a crucial update to the genophage virus afflicting the krogan race. During Shepard's mission to fight the Collectors, Mordin asks the Commander to help rescue him from a krogan clan, only to find out that not only was Maelon trying to cure the genophage, but he was doing it voluntarily. Mordin can execute him unless Shepard intervenes, after which he disappears. Come the Reaper invasion, the data that Maelon gathered doing his experiments proves crucial to finalizing the new cure required to arrange an alliance between the turians and krogan against the Reapers. If Shepard convinced Mordin to keep the data, then the female krogan survives the development process and helps to usher in a new age for the krogan, but if it was destroyed, then she dies trying to finish the cure, an outcome that's only made worse if the Urdnot clan leader is Wreav instead of Wrex.

* The ''WesternAnimation/TheLoudHouse'' fanfic ''Fanfic/RequiemForALoud'' has Adrien, a boy slightly older than Lincoln, who suffers from an advanced form of Leukemia. He only appears in chapter 5, but both this meeting and the letter he writes Lincoln later mark a turning point for Lincoln, and the story as a whole, since it causes Lincoln to accept his fate and try to make the most of the time he has left.

* ''LightNovel/RollOverAndDie'': The black market slave merchant appeared in only the first two chapters of the light novel, but the impact he has is immense. If it wasn't for him, Jean would not have had the opportunity to sell Flum into slavery. This causes the Hero's party to start to break apart due to Flum being TheHeart of the party and Jean being short sighted. Additionally, this leads to Flum discovering the the true nature of her affinity Reversal, and she also meets Milkit along with beginning her own Hero's journey.

*** And probably the biggest of the three, Oliver Sansweet. The guy only has two scenes, but his attempted suicide and lawsuit against Mr. Incredible once he stops him and injures him in the process open the floodgates for the lawsuits that become the reason for the Registration Act. Better yet, when Mr. Incredible attempts to stop his suicide, he tackles Sansweet into the bank that is being robbed by... Bomb Voyage.

* ''VideoGame/FireEmblemAwakening'', as is the norm for the series, has [[LoadsAndLoadsOfCharacters a massive cast]] with most of the characters having little to no actual part in the storyline. Early on in the game, Maribelle, who herself has only a ''slightly'' larger part than most of the other playable units and loses all plot relevance shortly into the game, is held hostage by Plegia and used as a [[TheScapegoat scapegoat]] to start its war with Ylisse, kickstarting the storyline as a whole.

** [[spoiler:Grisha Jaegar]]. No one has seen hide nor hair of him since very early in the series. Even so, [[spoiler:it's heavily implied he knows many mysteries about the Titans, and is the one who gave Eren his Titan Shifting powers, via a mysterious injection. All of this is confirmed through a flashback, [[ThanatosGambit plus the reason why he isn't there]].]]
** Perhaps even more so is [[spoiler:Eren Kruger]], who only appears in the flashbacks of the character mentioned above, but is essentially responsible for all the events in the series turning out the way they did -- [[spoiler:Grisha met Kruger when he was a child and was present on the day Grisha's sister was killed. He's the reason why Grisha joined LaResistance and met his first wife Dina and it's because of him that Zeke Yeager, the Beast Titan, was born. Zeke then betrayed his parents and they ended up on Paradis Island with the other members of their group. Kruger was then the one who saved Grisha's life and gave him the powers of the Attack Titan, which Grisha then bequeathed to his son]]. [[UpToEleven To top it all off]], he's ''also'' the inspiration behind [[spoiler:[[DeadGuyJunior the protagonist's name]]]]. Safe to say that the story would be ''very'' different if he and [[spoiler:Grisha]] had never met.