History Main / SailorEarth

** Fans tend to create their own stitchpunks with numbers of 10 and higher. Which may or may not totally defeat their original purpose, or maybe the fans just imagine themselves to be the scientist's partners who all decided to band together and create an army of stitchpunks for a more likely chance of destroying the machine, or... whatever, my brain hurts.

** It's implied that the four canonical kids are the only ones left, given that there seem not to be more "exiles" and the kids' meteors are by far the biggest ones (presumably marking them for the only session that actually gets in). It's implied that nobody else who actually received the game actually got into the medium because they [[PlotInducedStupidity couldn't figure out how to get into the Medium]], which is portrayed in canon as a fairly simple process. [[MisaimedFandom This of course is totally ignored by fan-adventure writers.]]

** Some people take this to [[UpToEleven ridiculous extremes]] by suggesting that ''every'' story in the universe is a part of Ever After High's endless cycle and creating characters to match. For example, [[https://unmaskedagain.tumblr.com/post/618509910834102272/raven-leonard-queen-based-on-my-biodad-au-of this]] AU fic has the Evil Queen marry (and have Raven with) her generation's [[Literature/TheSagaOfDarrenShan Steve "Leopard" Leonard]], and a character tries to cover up an unexpected TeenPregnancy by lying that she's this generation's Series/JaneTheVirgin (with other characters dismissing the idea she could be Film/{{Juno}}).

* ''WebAnimation/BattleForDreamIsland'' {{Original Character}}s, known more generally as object show [=OCs=], are rather simple to create: choose an object, and... that's it. Optionally add an "-y" to the end of the object's name.

* ''Franchise/MyLittlePony'' has LoadsAndLoadsOfCharacters already, so a few more wouldn't make a big splash. Most G1-G3 fanworks revolve around [=OC=] ponies. Many were {{Winged Unicorn}}s, which wouldn't appear until G4 (''Friendship is Magic'').

'''Please''' do not add personal examples of the trope in the list below. The list is for discussing general trends of the trope or official examples.

'''Please''' do not add personal examples of this to the page. This is discussing general trends of the trope or official examples.

!!Examples:

* In ''Franchise/{{Danganronpa}}'' it's incredibly easy to make a new Ultimate Student: all you have to do is give them a talent that hasn’t appeared in the series yet (though duplicates sometimes exist in canon), a [[AnimeHair weird hairstyle]], and a couple of personality quirks. There's already [[https://www.deviantart.com/star-driver567/art/Dangan-Ronpa-ID-Card-Template-440756735 a template in the franchise]] for information on each student, making fan-made characters even easier to describe. Since the only recurring element from each entry in the franchise is the presence of [[BigBad Monokuma]] [[spoiler:and Junko Enoshima]], entire killing games can be made from a cast of [=OCs=]. So many of these types of stories have been made that [[FanNickname the fandom even has a name for them]]- Fanganronpa.

* Every other ''Film/SkyHigh2005'' fic seems to involve a new, oh-so-speshul student at the school with an [[OverlyLongName improbable name]] and various ComboPlatterPowers who quickly becomes the center of everything and makes out with [[EndearinglyDorky Will]], [[AllGirlsWantBadBoys Warren]], [[IdiotHero Zach]] or even ''[[DracoInLeatherPants Lash]]'' if female and [[UnluckyChildhoodFriend Layla]] or [[DatingCatwoman Gwen]] if male (we're not sure if we should pity or envy [[DeadpanSnarker Magenta]] and [[BlackAndNerdy Ethan]] that they're typically spared all this nonsense). The prevalence of such characters is without a doubt due to the sheer ease with which they can be created; there are almost certainly students and even teachers we didn't see in the film, plus the various unnamed characters we ''did'' see, all with unknown powers, and as noted above under 'General' the school setting makes "transfer student" a logical way to introduce a new character, as well.

** The ExtranormalInstitute setting and color-coded characters open a lot of room for Sailor Earths. Just pick a color, give the character an outrageous (and often impractical) looking outfit, an equally outrageous and complex weapon, a Semblance (a special power unique to the character) and you're done. For the furries out there, you can also make your character a Faunus by adding one and ''only'' one animal part to your character[[note]]so you can't have both [[LittleBitBeastly animal ears and a tail]], although some people just ignore that rule[[/note]], which may or may not come with additional powers such as SuperSenses, WolverineClaws, {{flight}}, or [[BewareMyStingerTail venom]].

Unfortunately, {{Mary Sue}}s appearing as {{Original Character}}s in [[SelfInsertFic Self-Insert Fics]] using this trope are common enough that some fandoms have a knee-jerk hatred of them. Especially when the trope is used to rehash ideas for a role that has already been filled in canon or previous fanfics. However, [[Administrivia/TropesAreTools this concept is not inherently bad and it can still be used legitimately]].

See also: SendInTheClones, ElsewhereFic, and FanCreatedOffspring. Compare ObviousCrossoverMethod. A would-be member of TheChosenMany. If a character of this type becomes {{Mary Sue}}ified, and then overhauled with more power than the canon should give them and then some, it becomes a CopyCatSue. Contrast TheUnchosenOne, who is a ''canon'' character who ''isn't'' a member of an order. Not to be confused with the webcomic ''Webcomic/SailorSun'', or with the trope SailorSenshiSendup (which is about expies of the ''Sailor Moon'' cast).

** And as ''VideoGame/FateGrandOrder'' demonstrates, you don't even need to have a Grail War, or stick to its limits on Servants, as it features a single Master calling on hundreds of Servants to assist them in saving humanity, including the various Extra classes from across the Fate series -- Avenger from ''VisualNovel/FateHollowAtaraxia'', Ruler from ''LightNovel/FateApocrypha'', Moon Cancer and Alter Ego from the ''VideoGame/FateExtra'' series, and Foreigner, an ''FGO''-original class.

** Most common examples are original characters for famous fairy tales that don't have canon ''EAH'' characters (especially ones with Disney versions). ''[[Literature/AlicesAdventuresInWonderland Alice in Wonderland]]'' original characters also pop up frequently due to several canon characters, as are ones for ''Literature/TheWonderfulWizardOfOz''. There are also [=OCs=] for more obscure fairy tales by Brothers Grimm, Hans Christian Andersen, and Charles Perrault, and even a few original characters for stories by more obscure fairy tale writers such as Madame d'Aulnoy and Andrew Lang.

* Many fans of WebVideo/{{Jreg}} have created new characters based on RealLife or fictitious ideologies not depicted in his videos.

[[folder:Anime & Manga]]
* ''Franchise/SailorMoon'':
** Any hypothetical Sailor Soldier, but especially the obviously missing "Sailor Earth". (This role is technically filled by Usagi's boyfriend and future husband Mamoru Chiba.[[note]]Mamoru/Endymion has the Golden Crystal, the Sailor Crystal of Earth; however the rule is that only women can be Sailor Senshi, so this makes his Tuxedo Mask form the closest to a canonical Sailor Earth.[[/note]]) The manga's creator later admits that none of the later Senshi were actually planned out before they appeared, since the series was initially intended to only feature the few girls to follow the FiveManBand rule; once the manga's fourth arc made canon the existence of ''asteroid'' Senshi with Sailors Ceres, Pallas, Vesta, and Juno, the door was flung wide open. As a result, any astronomical object tends to get Senshi,[[note]]though it's not likely anyone is going to make a Sailor 99942 Apophis or a Sailor 47 Ursae Majoris b[[/note]] and this was going on ''well'' before Pluto was demoted from planetary status. Stars are extremely common targets for fan Senshi, the most prominent continuing to be creating a Sailor Sun (aka Sailor Solaris if you're being technical). Although the Senshi's uniforms are shown to be vastly different around the galaxy with only the Sailor collar being the always present component (compare the Starlights and the Solar System Senshi), many OC creators tend to stick with the Sol Senshi uniform formula despite there being little to no evidence of Senshi elsewhere having similar uniforms; it's probably because it's the easiest to work with.
** An early appearance by a Sailor ''Pluto'' in the second story arc fueled the early speculation there should be senshi for Saturn, Uranus, and Neptune. {{Fanon}} versions of these senshi existed before canon versions, who were not introduced until the third arc. In the infamous ''WesternAnimation/ToonMakersSailorMoon'' that only had the first arc to go on, the absence of Saturn, Uranus, Neptune, and Pluto would have been a plot point.
** This trope also applies to villains, as the series employed largely gem or mineral based theme names to each villain group, with a slight tweak for themes. Thus, most fanfic villain groups find themselves named after whatever collection of gems or minerals the author thinks is menacing enough. Double points if that gem or mineral ends with "-ite" (common examples being "Quartzite" or "Pyrite") and triple points if they're a missing King (often mislabeled "General") from the first series.
* ''Franchise/DragonBall'': It is very easy to create a Saiyan without disrupting the universe's canon [[note]]it's simply a matter of saying "one more infant slipped through the cracks the same way Goku did" or "one more adult barely survived the purge of off-planet squads like Bardock, but this one didn't rush out to confront Freeza and get himself killed"[[/note]] -- so much so that [[Anime/DragonBallYoSonGokuAndHisFriendsReturn the 2008 OVA]] turned "Vegeta has a long-lost sibling" into AscendedFanon and introduced said sibling as a character. Other categories of Sailor Earths include Dr. Gero's creations (he sealed a number of them away as incomplete and/or failures, a plot point also taken advantage of by [[Anime/DragonBallZSuperAndroid13 one]] NonSerialMovie and [[VideoGame/DragonBallFighterZ one video game]]), Namekians (or any other stripe of alien -- ''[[Anime/DragonBallZ DBZ]]'' has a lot of them), and even the occasional Earthling (though not as popular, since they CantCatchUp). ''Anime/DragonBallSuper'' takes it several steps further with the introduction of other universes, of which several out of twelve have been shown in varying lengths. In Universe 6, alone, the Saiyans continue to thrive, and that's to say nothing of the other universes that haven't been explored or shown only glimpses of such wonders as ''Franchise/SuperSentai''-esque Pride Troopers of Universe 11 whom an OC could easily slip into. In addition, Universe 6's status as a mirror to Universe 7/canon means that Universe 6 aliens can be used as OC bases in Universe 7, such as the lava-powered robot-like Metalmen. In addition as Universe 6 humans, Namekians, and other races from the main universe haven't been shown, exploring them and creating an OC there isn't hard to do. Bonus points if they stick to the ThemeNaming all these have.
* In the ''Manga/RozenMaiden'' anime, there is another dollmaker named Enju, who only made one doll. He is often seen as a plot device with which to bring in more dolls without affecting the ''Rozen Maiden'' lineup.
* ''Manga/TokyoMewMew'' makes this easy; there's an almost infinite amount of [[ThemeNaming sweet foods]] and a lot of endangered animals.
* ''Manga/{{Bleach}}'':
** Since only a small fraction of the seated [[TheGrimReaper Shinigami]] officers have been revealed in the {{canon}}, it's easy to introduce new characters, especially in the less-known divisions like the first, the seventh, and the tenth.
** This also applies to the numbered Arrancar. 110 of them exist, but only about 20 of them have been shown, much less named. The novel ''Bleach: Spirits Are Forever With You'' by Ryohgo Narita takes full advantage of this.
** There are also the rare Visored Sailor Earth, Quincies who thought ''they'' were the last of their kind before meeting Uryu, humans like Chad, or other types such as variations of Quincy powers (since there's an entire world to explore and [[FillerVillain Bounts]] could possibly not be the only spiritually-aware humans), or other types of people with Kido-Shinigami powers like Orihime and Hachi. Of course, these people are often very rare -- possibly because these types are often rather harder to do than simply naming one-self as a seated officer or Arrancar who wasn't introduced.
** Rarely, one may actually have a Bount who ''wasn't'' rounded up by Kariya.
** The extreme ease (in both canon and filler) at which it seems ''anybody'' (regardless of whether they appear to be obviously the wrong age) can transfer into Ichigo & company's high school makes it that much simpler to introduce such an OC into the main characters' circle of friends.
** ''Bleach'' fanfic writers also tend to enjoy adding in a "14th Division," which allows them to make their OC a captain without killing off any of the existing ones. Oddly enough the Kido Corps (which was revealed in the Turn Back the Pendulum arc to be something akin to a "14th Division" in canon; though technically outside the Gotei 13 it still answers to the Central 46 and the Captain-Commander like the 13 Divisions do) rarely gets used, even though its missing Captain and Lieutenant never had canonical replacements introduced, ''none'' of its current membership have ever been named or even had their faces revealed, and the Corps has a secretive nature that gives writers a blank check for its inner workings.
** And now there are Fullbringers, humans who can have any power because their mothers were attacked by Hollows while they were pregnant with them. This is a blank check for any fanfic writers.
** The final arc introduces the Vandenreich who are revealed to be [[spoiler:Quincies]]. Their powers are far more diverse than what we had seen of [[spoiler:Quincies so far]], which opens up fan fic writers to think of their own abilities. However, as each member of this group has their power and epithet indicated by one of the letters of the English alphabet (known as a Schrift), one would either have to get [[Creator/DrSeuss Seussical]] with their letters or resort to a different alphabet entirely (as was the case with [[spoiler:Shaz Domino]], who is designated with Σ), as all 26 letters are already accounted for and only two letters are shared by multiple people (Y belongs to [[spoiler:a set of identical twins named Loyd and Royd Lloyd]] and A was [[spoiler:bestowed by Yhwach upon his intended successor, Uryu Ishida]]).
** There's also the nobility of Soul Society. Of the Five Great Noble Families, only the Kuchiki, Shihouin, and Shiba clans have even been named, and each only has two currently-living members revealed during the course of the story. The lesser nobles who are subordinate to the Great Families are even more of a blank slate, with the only information about them being that roughly a quarter of the captains and lieutenants come from these clans, the Ise Clan being one of said clans. The New Captain Shusuke Amagai arc additionally introduces the Kasumioji Clan, a high-ranking family said to be just below the Great Families in terms of prestige and something of an anomaly in this regard. Since nobles have much greater spiritual power than the average Soul Society resident and are far more likely to achieve Shikai and Bankai, this leaves plenty of room to quickly establish an newly created Shinigami as being a big deal even if they're fresh out of the Academy. It also potentially gives them access to special power-boosting relics.
* ''Anime/YuGiOh'':
** You could add character around a certain strategy (e.g. [[http://yugioh.wikia.com/wiki/Mill Milling]]).
** Another common fandom trend is an eighth Millennium Item, though usually the details of how it was made aren't explained.
** A lot of [=RPs=] take place in a ''Anime/YuGiOhGX'' era, where your character can simply be a student at the dueling academy.
** ''Anime/YuGiOh5Ds'' has the Signer Dragons. With Leo becoming the Sixth Signer, despite the show originally only having 5, this led to people making their own Signers and Signer Dragons.
** ''Anime/YuGiOhZexal '' fanfics often introduce Number Hunters, or people who hold Numbers, or [[spoiler:new Barians]]. Considering that, by series end, a few Numbers weren't shown yet, this leaves some wiggle room to bring in an OC.
** The many factions of ''Anime/YuGiOhArcV'' give people opportunities to introduce a new student to any of the dueling schools, or a character from another summoning faction. In particular, the lack of a canon Ritual Dimension opens up a lot of possibilities for fanon creations. Some even go as far as introduce a third character ([[MostFanficWritersAreFemale often a girl]]) with a set of [[AnotherDimension dimensional]] [[IdenticalStranger counterparts]], despite [[JigsawPuzzlePlot the plot not having even explained yet why there are already two]].
* Given the ''Manga/{{Claymore}}'' system of ranks and the fact that we haven't seen all of them, it's easy to imagine a Claymore who hasn't been seen yet filling one of the vacant numbers.
* ''Manga/JoJosBizarreAdventure'':
** Creating new Stand users is simple: [[MusicalThemeNaming pick two musicians, bands, songs or albums, then name the user after one and name the Stand after the other]]. There was originally a heavy bias for American and British rock from the '80s or earlier, but as time went on '90s references began trickling in, and [[Manga/JoJosBizarreAdventureSteelBallRun Part 7]] introduces Japanese pop while [[Manga/JoJosBizarreAdventureJoJolion Part 8]] brings in [=2010s=] American pop. The series doesn't even have a strong precedent for relating character or stand names to characterization or abilities, so you've got carte blanche to make whatever random music reference you like.
** When Stands were first introduced in ''[[Manga/JoJosBizarreAdventureStardustCrusaders Stardust Crusaders]]'', [[TarotMotifs they were named after the major arcana of tarot]] (with or without an additional word -- there's "Star Platinum," but there's also just The World), and later after [[Myth/EgyptianMythology Egyptian deities]] once the author had run out of tarot cards (e.g. Bastet). One could potentially use the minor arcana, court cards, or alternate names of the major arcana, and the many leftover Egyptian deities (or ''any'' pantheon if you really felt like it).
* ''Franchise/{{Digimon}}'':
** Any given series has a group of kids with {{Mons}} and Digivices, so generally it's a simple matter of picking a partner mon and a Digivice colour. Bonus points if the Digimon partner is entirely made up.
** For ''Anime/DigimonAdventure'', which already had an arc searching for a SixthRanger dubbed the Eighth Child, Sailor Earths often pop up under the title of the Ninth Child or higher.
** This is easiest in ''Anime/DigimonAdventure02'', which had a whole "World Tour" arc introducing kids with Digimon partners from outside Japan, and had the last episode state that, by the time of the DistantFinale, ''every single person on Earth'' has a Digimon partner. Also, once upon a time there was at ''least'' one multi-author FanVerse solely dedicated to ''02'' and the exploration of this trope in conjunction with ElsewhereFic.
** Also rather easy in ''Anime/DigimonTamers'', in which they could have been another tamer whose wishes were granted, or their partner Digimon actively sought them out.
** ''Anime/DigimonFrontier'':
*** There are four (potential) Sailor Earth positions to be filled: the four remaining Legendary Warriors. You know, the PsychoRangers from the first half who never made a HeelFaceTurn? At least one fanfic has their spirits given to humans (in this case, all four of whom are somehow related to the heroes from ''Adventure/02''). Alternatively (and as per a popular fan theory), the four remaining Spirits go to Katsuharu, Teppei, Chiaki, and Teruo, four other kids ''also'' [[CallToAdventure called by]] [[BigGood Ophanimon]] to the Digimon World for the same reason as the [[FiveManBand Six-Man Band]]. With Chiaki as [[TheSmurfettePrinciple the sole female of the four]], the gender ratio matches up perfectly with the vacant Spirits.
*** The fact that [[FusionDance Advanced Hybrids]] do ''exist'' for Izumi, Tomoki, Junpei and Kouichi ([=JetSilphymon=], Daipenmon, [=RhinoKabuterimon=], and Reichmon respectively) but never got to be used, opens the door for DayInTheLimelight {{Interquel}} chapters to showcase them.
** ''Anime/DigimonSavers'' fics tends toward new members of DATS; it helps that it's mentioned in passing that other DATS units operate around the world, including the Austrian one Touma came from early in the series, so filling the gaps in in those is pretty easy.
** ''Anime/DigimonXrosWars'' fics generally involve the creation of a human general, a lead partner Digimon, and an accompanying Digimon army, though there's no indication that other human-led armies operated at any time during the war against the Bagra Empire. ''Anime/DigimonXrosWarsTheYoungHuntersWhoLeaptThroughTime'' offers a more solid foundation -- it's clearly mentioned that Digimon Hunting is something of a sport with many participants, so having another Hunter is pretty believable.
* ''Franchise/{{Zoids}}'', in the ''[[Anime/ZoidsNewCentury New Century]]'' and ''[[Anime/ZoidsFuzors Fuzors]]'' series at least, involves an entire league of teams battling for fun, profit and prestige. How many fanfics have started with the main characters battling a new team? The same could be said of nearly any other competitive sports show out there; ''Franchise/{{Beyblade}}'', ''Anime/CrushGearTurbo'', ''Anime/BattleBDaman''...
* New Card Captors with either their own Clow Cards or another set of Cards in ''Manga/CardcaptorSakura''. They tend to ignore the canon facts that 1. the Cards were a new form of magic invented by Clow; and 2. the Final Judgment couldn't take place until all the Cards were sealed. This fanon aspect would later be made canon by the existence of the Clear Cards in [[Manga/CardcaptorSakuraClearCard the sequel series]].
* ''Anime/OjamajoDoremi'':
** Sailor Earths often pop up as the green Ojamajo. Similar to the [[Franchise/KingdomHearts Organization XIII]] case, a green Ojamajo, Nozomi, actually showed up in the [[OriginalVideoAnimation OVAs]]. The clue? [[spoiler:[[IllGirl She died from cancer]], and was the only character in the series to really die.]] Ojamajo fancharacters almost invariably show up as green, and named "Fasola," in order to establish some sort of ThemeNaming after Doremi. If not green, expect rainbow, or a mix of two or more colors, which will form an alternating pattern on their dress. Bonus points for black and/or red (even though, like [[spoiler:Nozomi]], there IS a red Ojamajo -- [[spoiler:Poppu]]) or if they are somehow related to [[IdolSinger Onpu]].
** Fairies in the show are named after the notes of the Solfège... except "So" and "Ti". As you might expect, a lot of fanmade fairies have one of those names.
* ''Manga/{{Chobits}}'' fandom is rife with extra Chobit-like persocoms, either as actual extra Chobits.
* ''Manga/{{Naruto}}'':
** The hosts of Tailed Beasts 3 and 5-7. The fact that a cover [[MilestoneCelebration celebrating the manga's 9th anniversary]] [[http://naruto.wikia.com/wiki/File:Jinch%C5%ABriki.jpg give designs for all of them]] despite [[spoiler:most of them being killed offscreen with little or nothing about them known]] just encourages this.
** [[spoiler:The Six-Tails host, Utakata, [[ADayInTheLimelight gets his own filler arc in the anime]].]]
** [[spoiler:For that matter, there apparently was no host for the Sanbi by the time we see it; Deidara and Tobi fight and capture the beast itself.]]
** There are also the extra tailed beasts people come up with later, e.g. the Ten-Tailed Wolf. Or the people who seal the yin half of the Kyuubi into another host. [[spoiler:It was eventually revealed that a Ten-Tailed Beast does exist, but it is actually the original tailed beast, the other nine being fragments of it split apart by the Sage of Six Paths.]]
** The fandom also seems to be in the habit of inventing other members of the Seven Swordsmen of the Mist, of which only Kisame, Zabuza, and Chojuro were mentioned. The more intelligent ones preserve the ThemeNaming and the odd swords. The less detail-oriented, and the filler writing staff, don't. Too bad all of them eventually showed up in-canon. ([[spoiler:Albeit as zombies in most cases.]]) Though given that the Seven Swordsmen recruit new members to replace those who die or leave the group and Chojuro is the only active member by the time of the final arc, there's plenty of room for replacement members to be invented. [[spoiler:And in the epilogue, Chojuro has been promoted to Mizukage, meaning his own slot is presumably open for a successor as well.]]
** For that matter, not only are the 5 major villages relatively little-known, but the canon map displays a dozens of tiny countries that could house new minor ninja villages; the filler writers certainly made good use of this.
** Not that there isn't plenty of Sailor Earth material in Konoha itself. Just have a character be from some second-tier clan with some "(usually a Japanese word)-gan" Kekkei Genkai. Or even make them a long-lost Uchiha or Uzumaki clan member. Or make them a member of one of the other clans that "only" have specialized techniques and not a bloodline ability, like the Nara or Akimichi.
** SpinOffspring series ''Manga/{{Boruto}}'' made way for a new type of Sailor Earth: next-generation characters. Like a character and they apparently have no kids yet? Make some for them! Most of the Konoha 12 have at least one child, however that leaves room for characters like Kiba and Tenten who don't. There are also OC siblings for the existing characters (such as Sarada receiving a, usually pink-haired, brother or Shikadai gaining a sister).
* ''Franchise/PrettyCure'':
** As a franchise, any given season of ''Pretty Cure'' features a stated theme and characters of various colors to represent it, called "Cure (Name)". Sometimes the theme isn't even strictly adhered to in the show itself, allowing for a lot more flexibility in character naming so long as they're still a "Cure". Hence, it's ''very'' easy to stick extra characters into a pre-existing season by picking an unused color from the palette to create a new Cure adapted to that season's lore and theming. Some fans take the idea even further and invent entire "fan seasons" using this format, creating entire teams of Sailor Earths loosely connected to the franchise.
** Until her identity was actually revealed, there were a reasonable number of fan-created red Cures for ''Anime/FreshPrettyCure'' based on the fourth petal of the clover logo. Since said clover also had a green center, the idea of a green Cure or Cure-like ally was also popular.
** ''Anime/HeartcatchPrettyCure'' saw a few yellow and purple Cures (possibly due to the logo featuring yellow and purple in addition to pink and blue)... but only briefly, as Cure Sunshine and Cure Moonlight's appearances were leaked very early on. There is still Sailor Earth potential -- in this continuity, there were [[PrecursorHeroes numerous Cures who had their own adventures long before the main heroines did]], though they only appear in-series as anonymous statues. This was even done ''in-universe''! When Potpourri was searching for the third Cure, he encounters Ban, who is trying to come up with a Sailor Earth of his own, Cure Fire, for his manga. When Potpourri suggests ''he'' be the third Cure, he starts imagining himself as such. Potpourri runs for the hills and Ban uses Cure Sunshine when she appears.
** ''Anime/SmilePrettyCure'' features a TransformationTrinket design with seven different-colored lights. Five of them correspond to the main characters. You can see where this is going.
** ''Anime/HappinessChargePrettyCure'' toys around with the trope, establishing other teams of Cures fighting the Phantom Empire around the world, thus allowing fans to come up with new Cures without affecting the core team. Cures are so common in this universe that people barely even react to them.
** ''Anime/HugttoPrettyCure'' really opened the floodgates by establishing the franchise's first male Cure, [[spoiler: Henri, who becomes Cure Infini. Then ''everyone'' in Episode 48 transforms into a Cure to help the main team. Anyone can be a Cure indeed!]]
* ''Anime/OnePiece'':
** Before Brook joined the crew, the fan-made crewmember was almost always given the job of ship's musician. These characters still pop up in ''One Piece'' fics all the time, though; they're simply given a different job, often one that is made up for the fic (such as "helmsman", even though the crew has never expressed the need for one and usually just take turns at the helm [[note]]though this eventually became Jinbe's position once he officially joined the crew[[/note]]). This likely stems from an early (and possibly outdated) statement by Luffy that he wanted ten crewmembers, and Jesus Burgess' position in the Blackbeard Pirates.
** Back before all the Warlords of the Sea were revealed, it was common for some OC villains to be this. This was back when Mihawk and Crocodile were the only ones revealed to be one and actually be made as characters, where Doflamingo and Kuma, while revealed, had little screen time. Other popular positions were Admirals and other high-ranking Marines. Since there were two vacancies among the Warlords [[spoiler:before the system was abolished entirely]] and an unknown number of former Warlords, and one Admiral with no information known other than his/her code name, there remains plenty of room for such characters.
** Original characters with any Devil Fruit the writer can imagine. Just think of a word, come up with powers that relate to it, and come up with a character to use it.
* ''Manga/FullmetalAlchemist'':
** The Sailor Earths usually come in the form of State Alchemists in their teens, proficient in a field of thematic alchemy.
** Extra homunculi. Never mind that the Seven Deadly Sins motif puts a firm cap on the number; plenty of fanfic writers don't care and just start coming up with their own vices. They were especially common for fanfics based around [[Anime/FullmetalAlchemist the 2003 anime]], where the homunculi were more complex characters and their origin story [[spoiler:as failed human transmutations]] was automatically tragic and could tie them in with the canon.
* ''Webcomic/HetaliaAxisPowers'':
** Since the characters are all {{Moe Anthropomorphism}}s of countries, it's very easy to create an OC by selecting any nation that hasn't shown up in canon; you can even opt to make a province like Canada's Quebec or The United States' states into a character. You're expected to do some research to make sure that your OC reasonably fits that nation/province's stereotypes and history, though, and inventing a country out of whole cloth just reeks of lazy writing and/or SelfInsertFic.
** Many people liked to put someone in for the missing North Korea, until a blurb on Himaruya's site was finally translated, stating many important details about him.
** A weird case happens with Latin American countries: Since the only Spanish-speaking countries that appear in the manga and the anime are Spain and Cuba, Latin American fanfic writers love to include Latin American [=OCs=] as part of the cast, even if many of those countries didn't have a steady contribution in UsefulNotes/WorldWarII.
** Just search "[[WesternAnimation/{{Animaniacs}} Yakko's]] World Hetalia" on Website/YouTube to get an idea of just how many of these characters exist.
* ''Manga/SoulEater'' takes place in an ExtranormalInstitute and only focuses on three students at that school, leaving the rest of the students open to any fanfic writer's desires.
** Seven if you count the weapons (who do indeed have to attend classes and take exams). Given that there are only six other students (three meisters and three weapons) who have even minor plot relevance, and barely more than that are so much as given ''names'', an author could easily add dozens of [=OCs=] without the slightest contradiction of canon.
* ''Manga/Reborn2004'' is a story with only the most prominent mafia families in that universe. Also, the Vongola might have quite a lot of enemy families. One can easily whip up their own family with some Italian-like name, and then fill it with many original characters.
** Actually having more than seven rings and seven colors was sorta canon, as said in one of the games, but there was a specific reason why the topic of an eighth ring isn't touched upon.
** The Vindice seem to be the only known characters in canon that have access to the eight element, and it seems to be so powerful that [[spoiler:Daemon Spade thought that if he had it, he could beat the combined forces of Earth and Sky]].
* ''Manga/ZatchBell'' is a favorite with this trope because it allows for ''double'' Sailor Earth. Since most of the demon children on the run for Demon King were never introduced, it's no wonder fans write in their own Demons and Book Masters in periods were it was possible. Others go as far as writing about ''another'' competition TwentyMinutesIntoTheFuture despite the main character's motivation being ''ending'' said competition.
** In their defense, [[spoiler:the manga ending has Zatch winning and becoming King. In a letter to Kiyo in the epilogue, he reflects on the competition (called the God Trial) and noting the competition as an important and necessary thing. It was through this that many characters (Demons/Mamodos and Humans alike) underwent CharacterDevelopment, learned valuable lessons and grew to be better individuals, and the way Zatch words it implies that not only have the others realized this, this was the whole intent of the competition in the first place.]]
* Though rare, ''Manga/YuYuHakusho'' fanfics may involve a future spirit detective (since it is not stated whether or not Yusuke was succeeded by another teenager), another participant in the Dark Tournament or king's tournament, another student who wasn't taken by Dr. Ichigaki, a past student of Genkai, or someone from Mushyori city who became spiritually aware when the demon gate was opened (since Genkai stated that there were a lot more people who came to her after developing powers than just Kaito, Yana, and Kido).
* ''Manga/InuYasha'':
** Sailor Earths may be another human, demon, or hanyou who was cursed by Naraku or has another bone to pick with Naraku for some reason. Naraku ''does'' have a ZeroPercentApprovalRating, so it is only natural everyone has a bone to pick with him.
** Creator/BandaiEntertainment used this for their ''[=InuYasha=]'' RPG adaptations. ''VideoGame/InuYashaTheSecretOfTheCursedMask'' for [=PS2=] has either a boy or a girl and ''Secret of the Divine Jewel'' for NDS has American transfer student Janis, all of whom are Kagome's {{Expy}} upon their introductions. While they have their own plots, the whole point is only to have their original characters go on a quest along with the FiveManBand.
* ''Manga/DeathNote'' has Wammy's House, with 26 letters (or the combined total of all alphabet letters) of Sailor Earth goodness, for your crazy detective needs, usually a crossover of copies of L or other canon Wammy attendants.
* The number of unused ''Three Kingdoms'' or even ''VideoGame/DynastyWarriors'' characters in Toys/BBSenshiSangokuden, coupled with the immense amount of leftover Gundam mecha provide prime fodder. Xiao Qiao Methuss, Cao Zhi Airmaster, Cao Ren Leopard...
* For ''Manga/KamichamaKarin'', all you need is another Greek god.
* ''Franchise/LyricalNanoha'', from ''[=StrikerS=]'' on with its MildlyMilitary setting, allows for the existence of other TSAB teams and units that can act alongside the canon characters.
* It's very easy to make a magical girl for ''Anime/PuellaMagiMadokaMagica'', what with the ''billions'' of girls on earth to be contracted in past, present ''and'' future, and the revelation that Kyubey's kind visit other planets as well only made it easier. The only ''real'' requirements are [[spoiler:they have to have misery in their lives in some way, their soul is now outside of their body, [[BreakTheCutie and they will either break]] [[KillTheCutie or die]], depending on how cruel you are.]]
** One can even make another Incubator if they wished. Since ''Manga/PuellaMagiKazumiMagica'' revealed [[ThemeNaming Juubey]], people are running with the idea of them being a numbered series. [[spoiler:As it turned out, [[RogueDrone Juubey was a special case]], and his name isn't (entirely) a number pun.]] The theory has been {{Jossed}} to some degree, since WordOfGod and several spin-offs suggest that the species is an [[TheStoic emotionless]] and uniform HiveMind. However, Kyubey admits that there are members of his species who suffer from a "[[GrewBeyondTheirProgramming mental disease]]," which has prompted the creation of many a DefectorFromDecadence... or the occasional creature that would be evil [[EvenEvilHasStandards even by their standards]].
** If your story is set previous to the end of the series, it is also fairly easy to create your own [[EldritchAbomination Witch]]. There is an infinity of them all across the ages, with an infinity of gimmicks, new ones appearing every day. There's even a template all laid out for you by the official descriptions: a name, a [[MindScrew mindscrewy]] design, a nature and a short description for the witch herself. Another name, design, duty and short description for her minion. Given that "birdcage witch" and "class representative witch" are valid Witch gimmicks (both appear in the anime), then you can see Magical Girls can ''never'' run out of enemies to fight.
** As shown in ''Anime/PuellaMagiMadokaMagicaTheMovieRebellion'' [[spoiler:witches can still appear after the end of the anime, but only under special circumstances. Also, they can now be [[GuardianEntity Guardian Entities]], or the result of VoluntaryShapeshifting.]]
** Thanks to ''VideoGame/{{Magia Record| Puella Magi Madoka Magica Side Story}}'' and its many playable magical girls, it's now possible to make a magical girl summonable in that series as well. Introducing the concept of Doppels (forms where a magical girl is half-fused with [[spoiler: their personal witch]]) also allows them to come up with what their integrated powers look like.
* Thanks to ''Franchise/{{Gundam}}'''s rich history, especially in the [[Anime/MobileSuitGundam Universal Century]], it's not impossible for some hotshot rookie who is a Newtype/Cyber Newtype/Gundam Fighter/Coordinator/Innovator/what-have-you pilot some super awesome Gundam to fight the evil forces of Zeon/The Titans/Neo-Zeon/Crossbone Vanguard/Zanscare Empire/OZ/ZAFT/A-Laws/what-have-you. It doesn't help that, in the One Year War-era, we've seen tons of fronts of the Federation/Zeon war.
** A good rival for this kind of character would be a mysterious man with a CoolMask who pilots a red Mobile Suit with three times more advanced specs than the standard model. Why not? [[CharClone It's common in canon!]]
** And it's really easy to come up with new Mobile Suits. Simply take an existing model (Zaku, Leo, GINN), change its design a little, and you have an instant variation. It's flat out encouraged by the [[AllThereInTheManual Mobile Suit Variations supplemental material]].
** Doesn't happen as often as you'd think with the fan-favorite ''Anime/MobileSuitGundamWing'', since [[MostFanficWritersAreGirls most writers]] focus on [[{{Bishonen}} other]] [[HoYay subjects]] ''besides'' the war with OZ. Interestingly though, ''VideoGame/ShinSuperRobotWars'' pulled a variation on this by making the OriginalGeneration mecha R-Gun the Wing Team's SixthRanger, even having it be designed by Howard, a canon character who may have had the know-how to make a Gundam but not the inclination.
** ''Anime/GundamBuildFighters'' and ''Anime/GundamBuildFightersTry'' makes it just as easy to make a Sailor Earth of sorts, since it's normal people piloting heavily customized models (or not).
** With the advent of ''Anime/GundamBuildDivers'', the sky is officially the limit on both pilots and Mobile Suits. Since the series is set in an MMO with ''wildly'' variable player avatar appearance rivaled only by ''VideoGame/SecondLife'', a pilot can have any appearance imaginable, from default RPG protagonists like Riku to adorable [[UsefulNotes/FurryFandom furries]] like Rommel or hilarious [[Franchise/JoJosBizarreAdventure Araki-style]] bishonen like Magee. Mobile Suits are also only limited by the imagination, since the show features some extremely unlikely concepts like a SuperDeformed CombiningMecha, or a tiny penguin MetaMecha. Come up with your avatar appearance, design or redesign an existing Mobile Suit, perhaps come up with a themed Force group (the equivalent of MMO clans/guilds), and you're ready to go.
*** [[AllThereInTheManual In a series of model designs]] for ''Anime/GundamBuildDiversReRISE'', Captain Zeon unveils a companion unit for Kazami's Justice Knight Gundam based off of the Strike Freedom.
* The premise of ''Franchise/BlackRockShooter'' makes it very easy to come up with one. ''Every person in the world'', or at least every girl, is implied to have an Other Self in Otherworld, and so all fans need to do is fill in the blanks. A new person, usually a girl, easily gets shoehorned into Mato's school as a new student (or employee) with some sort of {{Angst}} and the corresponding Other Self, or the fan just dreams up their own Other Self. In addition, the existence of [[PaletteSwap White]] [[IdenticalStranger Rock]] [[EvilTwin Shooter]] practically begs for the creation of various copies and [[{{Expy}} Expies]] of the eponymous character.
* ''Manga/FairyTail'':
** These usually manifest as previously unknown Dragon Slayers, the most popular being of the [[MakingASplash Water]] element. [[AnIcePerson Ice]] and [[DishingOutDirt Earth]] (the element, not the planet) are also somewhat prevalent, along with a couple other, weirder ones, like Crystal or Light.
** Some people like to create new Celestial Spirits for Lucy (or, rarely, for a fan character) to use. As there are literally dozens of unused constellations to choose from, this leaves open a lot of potential. However, instead of being Silver Keys like all non-Zodiac constellations are ''supposed'' to be, these sometimes get hit with super-powerful White Keys or Dark Keys. Common constellations for these super keys include Pegasus, Canis Major, and Draco.
* ''Manga/DGrayMan'':
** Because the series only focuses on the activities of Allan's small group of Exorcists and a few Generals despite the Black Order having multiple branches across the world, it's not unlikely for people to create more Exorcists from those branches. Generals are included into the mix. Also, because of the lack of a recruitment age for Exorcists, many of them and some Generals tend to be implausibly young for the job.
** It doesn't take much imagination to come up with an Exorcist either. In general they need a weapon (usually a cool one -- {{Sinister Scythe}}s are popular) and an experience with Akuma before being recruited.
** When a new type of Innocence was introduced, many characters swiftly took on that type despite not having a lot of information on it at first, only based on the knowledge that the base two types of Innocence can transform.
** Any new Noah is guaranteed to have their own ability/ies and usually highly sadistic and attractive since it's not stated how many Noah there are total. Anyone normal-looking can turn out to be a Noah.
** Thanks to TheReveal about Allan and his connection to the Noah, there are inexplicably quite a few half-Noah Exorcists hanging around even if it's stated that Noah hate Exorcists.
* ''Manga/AttackOnTitan'' focuses on the 104th Trainee Corps, so there are plenty of characters hailing from past Trainee Corps who have survived to the present time of the story. Information released also indicated that there are North, East and West batches of trainees apart from the South batch (which is the focus of the story), and since the top 10 students are from each batch rather than from the entire 104th it is possible to make characters join the elite Military Police and claim they're not from the South 104th, to make up for the 30 trainees who aren't seen.
** The Stationary Guard/Garrison's massive numbers compared to the other military branches makes space for a lot of characters in various brigades or divisions.
** Can't forget the Titan Shifters. They usually have unique traits like the Shifters in the story, and either are for humanity or against humanity.
* ''LightNovel/AriaTheScarletAmmo'' focuses on a paramilitary academy where students are taught to use guns, stunt drive, collect information. It's very easy to create a student for that.
* ''Anime/CodeGeass'' has the Britannian Royal Family. With 108 consorts, each probably having 1+ child to their name, it is not hard to fanfic writers to fill in the [[BigScrewedUpFamily oh-so-loving household]] with original characters to have around. Either to make the family more human... or to give Lelouch CListFodder for his revenge when you run out of canon ones you want dead and it isn't quite time to kill Charles yet. For some context if we try to follow the numbers Lelouch had at least 10 older brothers as the 11th Prince, and 16 ahead of him as the 17th in line to the throne. We only know five siblings older than him/ahead of him in succession (the first and second Prince and Princesses, and the third Prince, as the third Princess Euphemia is younger than Lelouch). Two Princesses a bit farther down (possibly due to having been removed from the line of succession for the time) in Nunnally and Marrybell are the ''87th and 88th'' in line. As implied, there are a ''lot'' of open character slots.
* ''Franchise/{{Jewelpet}}'', thanks to its concept of tiny animals who represent minerals, has an ungodly amount of original characters based on minerals not (yet) used in the franchise.
* It's becoming a common trend to make ''Anime/KillLaKill'' fanfics centered around other students of [[AcademyOfAdventure Honnouji Academy]], usually they're either club presidents or one of Satsuki's associates.
* ''Anime/NeonGenesisEvangelion'': Nth Children, Nth Angels, Nth Evangelion Units, extra bridge bunnies, SEELE agents... It's such a popular plot that even ''Anime/RebuildOfEvangelion'' and [[TheRoleplayingGame the official]] TabletopRPG of the series ("The White Paper", [[NoExportForYou Japan-only]]) runs with it.
* ''Manga/RanmaOneHalf'': Other victims of the Junsenkyo Springs is a pretty popular plot, as is the concept of other fiancees for Ranma (or a {{Love Interest|s}} for one of the other characters).
* ''Manga/FoodWars'': [=OCs=] tend to be either New Transfer Students to Tootsuki like Soma or someone who has "The Devil's Tongue" as a counterpart/{{Foil}} to Erina.
* Original Haibane are extremely common in ''Anime/HaibaneRenmei'' fics. A few are based on the BabiesEverAfter ending, however most are simply original characters with {{Dark And Troubled Past}}s who have unusual wings.
* ''Manga/GunslingerGirl'': [=OCs=] aren't hard to make. Just have a child with no guardians get transformed into a {{cyborg}} {{Child Soldier|s}} and given a [[TheHandler handler]]. It's known that there's more than one generation of cyborgs, however generation 2 barely appears. Some fanworks feature a [[TheOneGuy male cyborg]] character.
* ''Manga/MyHeroAcademia'' has an extremely fertile setting for [=OCs=], given that it's a world in which 80% of the human population is born with superpowers, ranging from [[WhatKindOfLamePowerIsHeartAnyway near useless]] to [[StoryBreakerPower completely overpowered]], to everything in between, and the main cast are the students of resident SuperheroSchool U.A. Academy; said OC will usually join U.A. as a NewTransferStudent, and will be placed in Class 1-A, presumably filling the vacant spot [[TheScrappy Mineta]] left after the author had him kicked out of U.A.
* ''LightNovel/ACertainMagicalIndex'' and ''Manga/ACertainScientificRailgun'':
** There are canonically millions of espers in Academy City, ranging from Level 0 to Level 5 (and a theoretical Level 6), leaving plenty of room for [=OCs=]. While there are only seven Level 5 espers, it's still possible to add an eighth one, and Aihana Etsu (the sixth Level 5) is still almost a complete mystery. There's also the concept of Gemstones, espers who are born with their powers unlike most espers, allowing for esper characters outside of Academy City.
** There are even more magicians, and magic in the series can be based on any religion or other belief system (including recent ones like the Cthulhu Mythos).
** Finally, there's the possibility of new right hand users. There are canonically three of them, each of whom has a unique power, so basically any power is possible.
* In ''Manga/{{Sekirei}}'', only about half of the canonically established 108 Sekirei have been introduced or given names. Plenty of room for fans to make new Sekirei.
* ''Manga/WorldTrigger'', due to the nature of Border being a fairly lax military organization based around [[ChildSoldiers kids and teens who fight evil]] with little to no fear of actual injury or death. Though many members of Border are trainees, the main fighting force is the B-Ranks, which is said to consist of around 100 people. The fact that only 30 out of these 100 have actually been named and introduced so far leaves plenty of room for fans to create their own squads within Border, each with named members, roles, and unique Trigger sets. One can also easily slip a new character into the canon by having them move to Mikado City and join Border as a trainee, since it's really just that easy (as long as you have the Trion).
** The series later establishes the seemingly endless sea that is the Neighborhood, and the different "planet nations" within it. Aftokrator in particular is said to be split amongst four major houses, which also have minor houses, and lesser houses beneath that! An OC can easily be introduced as a horned Neighbor existing within these houses, possibly with one of the many Black Triggers that the country is said to hold.
* Creating an OC for ''Manga/BungoStrayDogs'' is as easy as taking your favorite writer, and giving them a superpower named after one of their books.
* ''Franchise/{{Pokemon}}'':
** Creating new Trainers to meet Ash is not hard to do, given just how large the world is and how many tournament Trainers are not given personality for a perspective writer to take over as their own.
** On a similar note it isn't hard to add new Pokémon to a Trainer's roster.
* ''LightNovel/{{Overlord|2012}}'' is about a player of a futuristic full immersion MMORPG (called a DMMO-RPG) ending up in a fantasy world unrelated to his game, but with the appearance and skills of his in-game avatar. As an MMO "so popular that whenever the word "DMMO-RPG" was mentioned, listeners would immediately think of [it]," the game would doubtlessly have millions of players. Given the only (known) requirement for being transported to the New World is that the player be logged in when the servers were shut down for the last time, any of these potential millions of players could be a new OC.
** Bonus points for the game's in-universe main selling point being player freedom, allowing people to roleplay as anything from a KnightInShiningArmor or PrincessClassic to TheUndead or [[GiantEnemyCrab giant crab men]].
** Players were also given the ability to create their own custom [[NonPlayerCharacter Non-Player Characters]]. In the series, it's shown that these characters could be customized to the same extent as the players themselves, and could be used to defend player-owned areas and for roleplay. In the New World, all these characters [[AnimateInanimateObject come to life]] and live in accordance with their player-written backstories, providing an entirely different source for an OC.
* ''Manga/FushigiYuugi'' easily allows for a new Priestess to appear. And she can be from wherever the author is from, even if it's not Japan, because the book can make its appearance ''anywhere'' in the world, at ''any'' time. The Universe of the Four Gods has the Priestesses appear cyclicly (and ideally one at a time), although a writer could easily put in a Priestess for her favorite of TheFourGods (and favorite Seishi) out of order, and/or have two or more Priestesses appear at once. (Although, canonically, this ''will'' screw up the universe and require someone to come along and recalibrate it. This is almost never explored in most fanfiction, however.)
* ''Anime/DinoZaurs'':
** Take any creature that's been extinct long enough to leave fossils, give it a robot mode and a WeaponOfChoice, and play a news report where Kaito will see it about paleontologists finding a complete skeleton. You've now created a brand new Dino Knight.
** Bringing in a new human is even simpler; give them a Dino Dagger. That's literally all there is to it. They might find it themselves, or they might be handed it after promising to be a SecretKeeper; all that matters is that they have the Dagger.
[[/folder]]

[[folder:Literature]]
* ''Literature/HarryPotter'':
** New classmates, especially ones that they would never let be enrolled at Hogwarts in the books or movies. This could include such canonical characters as Blaise Zabini, whose existences were ''known'' but who had never appeared "on screen".
** Students (or former students/graduates) of Beauxbatons or Durmstrang may also show up.
** And what about exchange students from [[{{Eagleland}} Ilvermorny school for witchcraft and wizardry]]? Obviously common whenever an American fan wants to do a self-insert fic, with a variant being to use some of the canon characters as exchange students ''to'' an American wizarding school.
** There is also the common variant of Japanese exchange/transfer students, thanks to the frequent crossover between the anime and ''Harry Potter'' fandoms. (Especially common on [[Website/GaiaOnline Gaia]] roleplaying guilds.) This was helped when Pottermore [[http://harrypotter.wikia.com/wiki/Mahoutokoro named a Japanese school]]. Some RP groups address both problems by explicitly banning Hogwarts student characters who were not born in the British Isles.
** New professors, too; Defense Against the Dark Arts professors are of course especially common given the position's turnover rate. Implausibly young ones are worryingly common.
* ''Literature/PercyJacksonAndTheOlympians'' is constantly prone to a new demigod, which is made extremely easy by the ending of the fifth book [[spoiler:stating that more and more demigods will be claimed and are coming across the border to Camp]]. And the sequel reveals [[spoiler: that there's also a camp for the children of [[LiteralSplitPersonality the Roman gods]]]]. And ''then'' the sister series gave us not only characters [[spoiler: descended from Egyptian gods]] and an AncientConspiracy, but confirmed they all exist in the same 'verse. And the next series, ''Literature/MagnusChaseAndTheGodsOfAsgard'', gave us [[ExactlyWhatItSaysOnTheTin the Norse gods]].
* Fan fiction for ''Literature/TheLordOfTheRings'':
** Stories with a "Tenth Walker" in the Fellowship of the Ring are surprisingly common. There are only Nine Walkers in {{canon}}, so these stories are really {{Alternate Universe Fic}}s. The name "Tenth Walker" references ''[=LoTR=]'' Book II Chapter 3, when Elrond declares, "The Company of the Ring shall be [[ArcNumber Nine]]; and the Nine Walkers shall be set against the Nine Riders that are evil." After setting the number, Elrond chooses Nine and only Nine to become companions.
*** Some authors let the Nine leave Rivendell, and the Tenth Walker joins later.
*** Most stories with a Tenth Walker follow [[Film/TheLordOfTheRings the movies]], not the books. In the movies, members volunteer themselves, then Elrond announces, "Nine companions. So be it. You shall be the Fellowship of the Ring." It is easy to insert another volunteer and change Elrond's line to say, "Ten companions."
*** Some stories have Eleventh Walkers, Twelfth Walkers and so on.
*** The official board game indulges in a bit of this (though only in a full five-player game) by having Fatty Bolger accompany the rest of the hobbits to Mordor rather than staying in the Shire. It ignores the Nine = Nine idea because it doesn't use the Fellowship, only the hobbits.
*** A few writers get around the "nine walkers for nine ringwraiths" issue by adding a tenth ringwraith to correspond to the tenth walker.
** ''FanFic/TimeWillTell'' is unusual, because Jorryn joins the hobbits from Shire to Rivendell, but never becomes a Tenth Walker.
** A few authors invent a 21st [[RingOfPower Great Ring]], though canon has only twenty. Gandalf briefly mentioned some "lesser rings" in ''[=LoTR=]'' Book I Chapter 2.
** A few authors invent a sixth wizard. Canon has exactly five Istari.
* In ''Franchise/JamesBond'' fanfics, there will often be a character whose codename is either 00x or a letter besides M and Q. This is not helped since the movies have, at various times, either shown or mentioned 3 different 006s, 3 different 009s, 2 different 002s, a 003, a 008, and even a 0011. Most of the other 00 agents that have more than a passing mention in the movies tend to wind up dead shortly thereafter. It's very clear that not only do numbers get recycled when their former owners die, but that any given number works as long as it's preceded by 00 -- making 0013, 0069, 0099, or even 008675309 all valid code-names.
** Makes sense; 00 is simply an agent status, showing they have license to kill.
** Combined with the EpilepticTree that James Bond is merely a code name, there exist plenty of fanfics starring a brand new Bond after the previous one was killed/retired. At least it's better than ones about Bond being a WMG/TimeLord.
** Mildly lampshaded in the film version of ''Casino Royale''.
--->'''James:''' (''to M'') "Well, I understand double 0s have a very short life expectancy..."
* The ''Literature/WarriorCats'' fanbase is notorious for this. Most ''Warriors'' fanfics have no involvement with the canon characters. The most common ways to do this are to involve a kittypet kit joining a Clan, a twoleg (occasionally a reader transported into the series) being transformed into a cat and joining a Clan, the descendants of canon cats, or a random [=OC=] just plain being born into a Clan. There are also a lot of fanwork revolving around new Clans. The TrollFic ''Fanfic/StarkitsProphecy'' is an especially infamous example.
* Quite a few ''Literature/{{Animorphs}}'' fanfics have somebody new join the team. This plays out interestingly, because the Animorphs already had a SixthRanger, but he [[SixthRangerTraitor sold them out to Visser Three]] to get his parents back. So, naturally, there is some skepticism in the group if they want to take in another new member, TouchedByVorlons or otherwise. But it gets resolved within a chapter, after the OriginalCharacter promises not to kill them in their sleep, and Marco mentions he needs a pairing buddy.
** Another obvious mechanism: Vissers. Vissers Three and One are recurring villains, and with 47 Vissers, only a few of whom we've met, it's easy to bring in a new one.
** ''Alternamorphs'', the {{Gamebooks}} spinoff, actually embrace this trope. In the second one, the reader even plays as [[ForegoneConclusion the aforementioned Sixth Ranger]].
** There were also the Auxiliary Animorphs who were mostly people who were not suitable controllers (due to being disabled in some way), and a fanfic can easily put the new character in the shoes of one of them, sometimes with varying disabilities. (A good example would be somebody who is autistic and wouldn't be suitable because different behaviours would alert non-controllers that something is up.)
** There can also be another faction of Auxiliary Animorphs who were deemed unsuitable controllers for other reasons -- such as they are children and are too young to be of any use as of yet, they're too old, or they do not have the proper social status to become a good controller.
* ''Literature/TheClique'' has a common theme in their fanfiction: A new clique comes in and competes with the Pretty Committee.
* 99% of fanfiction for Mary Hoffman's ''Literature/{{Stravaganza}}'' series involves the introduction of a new Stravagante.
* ''Franchise/StarWarsLegends'' used this quite often.
** Obviously, at the end of ''Return of the Jedi'', Han/Leia is standard, but what about Luke? Enter Mara Jade.
** Who helped Leia get the Death Star plans? A former stormtrooper turned mercenary turned Jedi Knight named [[VideoGame/DarkForcesSaga Kyle Katarn]].
** Luke needs Jedi students, so... Kevin J. Anderson gave him a dozen. In the FixFic ''I, Jedi'', in addition to that dozen, Mara, and Kyle, we have Corran Horn.
** The surviving Y-wing pilot from ''A New Hope'' is canonically you in the ''X-wing'' games.
** So we have Jacen, Jaina, and Anakin. They need friends to join in on their adventures, plus show romantic subtext. Hence Tenel Ka, Zekk, and Tahiri, respectively. There's also Lowbacca.
* ''Literature/TheRailwaySeries'' [[AllThereInTheManual has]] ''The Island of Sodor'' and ''Sodor: Reading Between The Lines'', which suggest that there are eighty locomotives on the Fat Controller's railway alone, as well as a number of engines formerly working on Sodor and several branch lines, minor railways and industries that could be rail-served. Fanfic characters are therefore usually just a case of finding a gap in the Sodor stockbooks and dropping an engine (often [[AuthorAppeal the author's favourite class of locomotive]]) in. In many cases, as real locomotives have been turned into characters in the series proper, creating a character is often as simple as putting a face on a real engine and inventing a reason for them to come to Sodor.
* Most ''Literature/{{Holes}}'' fanfics have someone new coming to Camp Green Lake -- and it's almost always a girl, despite the fact that it's an all-boys camp. This is rarely even {{Handwave}}d.
* ''Literature/ASongOfIceAndFire'':
** Lost Targaryens who just ''happen'' to stumble on dragon eggs and start conquering stuff.
** There are a lot of noble houses in Westeros, but only a few of them have names: the rest are only mentioned by their heraldry. This allows for would-be Sailor Earth makers to create their own house by making up a coat of arms or taking one of the many heraldic designs described in the book. The ''A Song of Ice and Fire'' tabletop RPG by Green Ronin includes this as an option in its character-building process.
** It is not hard to add an original character in via an additional Sand Snake: [[ReallyGetsAround It is not hard to write Oberyn Martell having gotten another child into the world without stretching the suspension of disbelief]], and with how far he traveled there are very few origins for said child you can't realistically do (and most of them are probably genetic limitations).
* In ''Literature/TheHungerGames'', there are 73 past Games, meaning 73 opportunities for fans to invent their own victors provided they're not accounted for (after all, [[spoiler: the 75th Hunger Games had a special gimmick that past victors are Tributes]]). Not only that, but it also provides opportunities for 23 other Tributes, leading to a grand total of 1776 total Tributes that may or may not have been accounted for. There's also the Quarter Quells, special Hunger Games with different gimmicks. It's mentioned that there's more than three and they could stretch out to last hundreds upon hundreds of Hunger Games. And of course, if you wish to invoke the WhatIf scenarios, [[spoiler:[[LaserGuidedKarma A Capitol Tribute-based Hunger Games]] and [[BadFuture Hunger Games stretching from the 76th onwards]] are possible, and thus the Victors, Tributes, and Quells grow]].
* The ''Literature/{{Dragonlance}}'' series has an interesting inversion in the official ''Tales'' trilogy; a historian claims to have discovered evidence that there was a gnome member of the original 'Heroes Of The Lance', who was written out of the Chronicles and his existence completely hushed up by the rest of the heroes.
* With ''Literature/DragonridersOfPern'' fics and RP fora, this tends to manifest itself mainly in four ways -- all of which have ''some'' basis in canon:
** A dragon outside the five standard colors (female Greens and Gold/Queens, and male Blues, Browns and Bronzes); one that isn't a sport or a runt like Ruth (canonical White dragon). Often written to have special abilities (the ability to talk physically as well as mentally being a popular one).
** Female Bronze/Brown riders and male Queen riders.
** Riders with Journeyman Craft ranks (usually Harpers)
** Children of Lord Holders (Pernese equivalents to princes and princesses) becoming riders. This one does apply to canon character Lessa, established in ''Masterharper of Pern'' (covering Robinton's life up until the main series begins) as the daughter of the Lord Holder of Ruatha and the only survivor of her family after Fax's takeover.
* The majority of ''Literature/MaximumRide'' fanfics and [=RPs=] features a new mutant or group of mutants that has broken out of a lab. The former always joins up with Max's [[spoiler:or Fang]]'s flock and the later usually becomes their own.
* Creator/HPLovecraft's Franchise/CthulhuMythos is essentially a huge bunch of professional fanfics of the CosmicHorrorStory's TropeCodifier, and was that way even during Lovecraft's life, as he and his author friends freely cribbed from each other. Many writers have added their own [[TomeOfEldritchLore forbidden books]][[http://en.wikipedia.org/wiki/Cthulhu_Mythos_arcane_literature]], [[StarfishAliens weird species]][[http://en.wikipedia.org/wiki/Category:Cthulhu_Mythos_species]], [[EldritchAbomination god-things]][[http://en.wikipedia.org/wiki/Cthulhu_Mythos_deities]], and Masks of [[http://en.wikipedia.org/wiki/Nyarlathotep Nyarlathotep]] to the mix. A positive example, as many of these have become quite popular among fans.
* ''Literature/SurvivorDogs'' original characters are significantly rarer, due to the ''much'' smaller fandom size, compared to sister-series ''Literature/WarriorCats'', but they still pop up. They're pretty much all Leashed Dogs who join the Wild Pack after their owners evacuate due to the earthquake.
* Want to create a new ''Literature/MrMen'' or Little Misses character? Couldn't be simpler! Just draw a brightly coloured simple shape, add a distinctive characteristic, name the character after that characteristic, and there you go!
* ''Literature/HeraldsOfValdemar'' makes it all too easy to add a character who is one of TheChosenMany. If being a Herald or a Companion doesn't suit you, you can join the Bards, the Healers, the Tayledras, Shin'a'in, or Kale'da'in, any number of mentioned religious orders, any number of named mercenary Companies, any number of named non-human races, or even become a member of any one of those groups ''in the past''.
* Since most of the plot of ''Literature/{{Worm}}'' takes place in the American North East, it is easy to write about events that take place in other parts of the world either as a member of the Protectorate/Wards or one of the superpowered gangs that will fight that particular branch. Inserting new characters into Brockton Bay itself is also easy with transfers from one Protectorate branch to another.
* Very common in ''Literature/DaughtersOfTheMoon'' fanfiction. Since the Daughters are either predestined by birth or granted the title by Selene after they earn her favor, many fanfics involve a new girl with mysterious powers moving to L.A., meeting and befriending the original team, and then discovering that she's a Daughter of the Moon. Either that or the author will create a whole new team of Daughters altogether.
* Literature/WingsOfFire makes it easy. Just choose a tribe and follow the naming conventions of said tribe and you're good to go. As of this writing there are ten tribes to choose from and plenty of fans have come up with their own tribes.

[[folder:Live-Action TV]]
* Any series with a MonsterOfTheWeek formula, like ''Series/{{Smallville}}'', makes it easy to introduce a new superpowered character.
* This is easier in ''Franchise/PowerRangers'' than you might think. Considering nearly every team leaves at least one common ranger colour out and the canon [[TheSixthRanger Sixth Rangers]] are allowed to join up late too, all it takes is to pick a season, pick a colour they didn't use, throw a little ''DeusExMachina'' in here and there and voila! The White Ninja Storm Ranger! The Green Dino Thunder Ranger! The Black Mystic Force Ranger! And that's without getting into seldom-used or even non-canon ranger colours.
** Parodied in ''[[Series/PowerRangersSPD S.P.D.]]'' in which one of the minor characters lied to his parents, claiming he was not just a ranger, not just the ''leader'' of the Power Rangers, but the first ever ''Orange'' Ranger. Ironically, ''Franchise/SuperSentai'' did once have an Orange Ranger: Battle Cossack from ''Series/BattleFeverJ''. A few other Orange Rangers emerged in ''Sentai'' years later.
** Similarly, in a few seasons of ''Super Sentai'' there have been people who tried to join the rangers by making their own original ranger costume, which doesn't actually give them any powers. This has happened in ''Series/BakuryuuSentaiAbaranger'' with [=AbarePink=] and ''Series/DoubutsuSentaiZyuohger'' with Zyuoh Human. [=AbarePink=] made a return in ''Series/KaizokuSentaiGokaiger'', much to Ahim's embarrassment.
** With the government/military-based teams, it becomes a very simple thing to have a random joe in the organization get promoted and saddled with a blank power template. This is especially the case for ''S.P.D.'', which canonically had several squads of Rangers already.
** There are entire ''teams'' created to fill a Power-Rangers-Equivalent of Sentai teams preceding ''Series/KyoryuSentaiZyuranger''. Or the five normal [[Series/GoseiSentaiDairanger Dairangers]] who never got their suits used. Some even go ahead and make future Ranger teams based on the most recent Sentai that haven't been adapted yet. ''Series/PowerRangersMegaforce'' even indulged in some of this canonically, letting the rangers transform into unadapted Sentai teams, though the show gave little to no explanation for where these powers came from, only that they weren't from Earth.
** Thanks to the number of additional mecha that get piloted remotely, it's easy enough to design new Rangers after them. Canon already has the Titanium Ranger (whose colors don't even match his Max Solarzord, but still counts) and the ''[[Series/PowerRangersJungleFury Jungle Fury]]'' Spirit Rangers. In toy form, we have the hideous repaints of the [[Series/PowerRangersOperationOverdrive Operation Overdrive]] Rangers that come with the bikes, and three original Rangers for the Paleomax Megazord of ''Series/PowerRangersRPM''. Those are just the tip of the iceberg when you consider that ''Series/PowerRangersWildForce'' by itself has up to 94 unassigned Wild Zords, the majority of which were never defined in the show...
** There's also the Rangers or Ranger-like heroes that were in the {{Great Offscreen War}}s and {{Cryptic Background Reference}}s -- previous ''Wild Force, Mystic Force'', and ''Samurai'' teams existed and ''so'' little is known of them. Lotsa fanfic fodder there.
** A semi-canon example exists for ''Series/NinpuuSentaiHurricaneger'' in the form of [=TentoRaiger=], introduced in the second season of ''Series/HikoninSentaiAkibaranger''. However, she was a villain--so naturally, the door is left open for fans to imagine what a version of her on the side of good would be like.
*** [=TentoRaiger=] may have been inspired by a WhatCouldHaveBeen plan for ''Series/NinpuuSentaiHurricaneger'''s addaption, ''Series/PowerRangersNinjaStorm'', which would have added a female dark yellow ranger to the Thunder Rangers so that there would be two female rangers and the two ranger teams would both have three members.
** Aditionally, the monsters in the second season of ''Akibaranger'' are Sailor Earths for the monsters of the various official Sentai series, being designed in their style and following their ThemeNaming. When three new members are added to a group of monsters that were named based on the days of the weak, this has the consequence of changing reality so there are ten days in a week.
** It is also speculated that in the reality where the Akibarangers replaced the Dairangers, since [=KibaRanger=] became their fourth member there would have been a fifth member called [=ARanger=], but no information is given about what [=ARanger=] would have looked like.
** ''Series/KaizokuSentaiGokaiger'' has the heroes transforming into past Rangers and gaining access to their powers. In addition to the idea mentioned above (inventing new colors like Gokai White), one fairly popular fan art came up with the idea of Gokai Killer, an EvilCounterpart who could change into Ranger-like enemies like [[Series/ChoudenshiBioman Bio-Hunter Silva]], [[Series/HyakujuuSentaiGaoranger Duke Org Rouki]], and [[Series/GoGoSentaiBoukenger Yaiba of the Darkness]].
** In the thirtieth anniversary movie of ''Super Sentai'' a special ranger called [=AkaRed=] who is the embodiment of all red rangers appears, and has since reappeared once every five years for anniversary celebrations. This has lead to speculation that there are other rangers like him who each embody a different ranger color and would be his teammates. During one of his later appearances he confirms that other rangers like him do exist but the blue member of his team is called [=AkaBlue=], not [=AoBlue=], though this happened in a non-canon miniseries so this might not be true.
** ''Series/PowerRangersDinoCharge'' is the first season without a yellow ranger, which means there are plenty of fics out there where someone finds the missing yellow energem and fills that gap.
** One of the unadapted sentai teams that showed up in ''Super Megaforce'' were the Super Sonic Rangers, who were based on ''Series/ChikyuuSentaiFiveman''. A Power Rangers comic book reveals the backstory of these team. The team included an original Sixth Ranger, Super Sonic Green, who became a SixthRangerTraitor, and destroyed the team and then became an original {{Psycho Ranger|s}}, Psycho Green.
* There are several teams in ''Series/StargateSG1'' that have been mentioned but never seen, leaving a lot of wiggle-room for fans. This one especially is ''really'' easy, as not only is Stargate Command just a US Government agency instead of some weird group of Destined Ones, "SG-1" itself is just a serial designation. Want a full roster of [=OC=]s? No problem, welcome to SG-7. Making it even easier is the fact that there are at least 9 SG teams in canon from the very first episode, up to at least 25 by the 10th season, with the audience getting to see what SG-1 is doing 99% of the time, with the occasional appearance to SG-2, [[SemperFi SG-3]] or SG-4 members. That's at least 100 potential characters. Add to that the fact that the teams are at least somewhat specialized (to say nothing of the Russian team, with a new one most likely being formed after SG-4 was wiped out), and you've got even more to play with. And that's not even counting the people who are almost certainly going to add SG-0 as a secret black ops unit that's better than SG-1 but who nobody knows about.
** With the upcoming ''Stargate'' [=MMO=], it seems likely that players will get to take their SG-Whatevers into the virtual plane. Watch as clans of avatars take on even the toughest of Goa'uld! Of course, video games are generally all [[TheChosenOne about]] [[TheUnchosenOne that]].
** The Goa'uld themselves. Even with the necessity of excluding the Norse pantheon, there's a vast number of mythological deities who were never used in canon. That's a lot to pick from if a fanfic writer wants an OC villain for their OC characters to confront. And with regard to the Norse pantheon, only a handful of the Asgard actually made appearances in canon.
* The same thing happens with ''Series/{{Torchwood}}'', for which the main characters for series 1-3 worked for "Torchwood 3" -- though canon gives explicit designations for 1, and 2, 4 has vanished and is easily brought back for fanfic purposes, and it's not entirely ridiculous to imagine there's Torchwood 5, 6, e, -90423, or what have you. [[spoiler:By ''Children of Earth'', however, it seems that all Torchwoods had been shut down, leaving only a remnant successor with no permanent base [[Series/TorchwoodMiracleDay two years later]]]]. It used to be that you could at least insist Torchwood was solely based in Britain. Following the introduction of Torchwood India in the audio drama "Golden Age", it's quite reasonable to assume there are branches all over the former British Empire, as Torchwood was founded by UsefulNotes/QueenVictoria. Audio drama "The Dollhouse" extends it even further, as it introduces the first branch based outside the Victorian Empire, Torchwood Los Angeles.
* Common are ''Franchise/StarTrek'' fanfics about Starfleet, since we don't even know how many ships there are. At an absolute minimum there must be hundreds.[[note]]WordOfGod from Ron Moore specifies a 30,000 ship fleet as of ''Series/StarTrekDeepSpaceNine''.[[/note]] There are many ships that the main heroes cross paths with for one episode, and it's easy to crew them with [=OCs=].
** It's also possible to do it with ships, as they have themes. Need a new [=DS9=] runabout? Think of a river! Need a new ship the same class as the local version of the ''Enterprise?'' Think of a modern battleship!
** This is also possible with military and crime stories in a contemporary setting like ''Series/{{JAG}}'', ''Series/{{NCIS}}'' & ''Series/NCISLosAngeles''.
** This is done in the ''Literature/StarTrekNovelVerse'', in which the ''Titan'', Riker's command as of the end of ''Film/StarTrekNemesis'', is a ''Luna''-class starship, and each starship in that class is named after a moon...thus giving endless FanFic opportunities there. Nor does it necessarily have to be a moon from our solar system; for example, the names of two Bajoran moons are known. Likewise the ''Literature/StarTrekDestiny'' series establishes that there are at least seven ''Vesta''-class ships, four of which are named after four of the seven hills of Rome (meaning Palatine, Viminal, and Caelian are still open).
* ''Franchise/KamenRider'', especially in the Heisei era, has the potential in spades, especially with some series that leave the possibility open or even pointedly declare that it could happen.
** There's a general rule of thumb for all Kamen Riders: Unless stated otherwise, the Rider Belts can work for ''anyone''. Almost all the Kamen Rider shows have shown at least two people donning the same belt, with Faiz being the most memorable example, as all three main belts had a go at changing hands every so often.
** ''[[Series/KamenRiderKuuga Kuuga]]'' averts this somewhat. Yuusuke was the only rider in the show, but outside of the show, be it sequels or [[AllThereInTheManual stories related to the show]], there have been at least four other Kuugas. Two of which are from alternate universes, one of which now has his belt in Yuusuke's possession, and the last one, the one where the Sailor Earth potential kicks in, found a prototype belt.
** ''[[Series/KamenRiderAgito Agito]]'' explicitly says that all humans have the potential to become Agito, and even if they don't, there's always a G3 style suit lurking around. In fact, whatever happened to G1 and G2? The S.I.C. toyline actually makes use of this, by having a Lord find and fuse with the G1 suit, which had been in storage in the police department's basement with other prototype weapons.
** ''[[Series/KamenRiderRyuki Ryuki]]'' had this in spades, the existence of Abyss (see below) adding even more to it, as it was possible that any of the massive number of Mirror Monsters could become an Advent Beast for a new Rider. There was even a bit of teasing about this via WhatCouldHaveBeen, with a piece of official art showing Kamen Rider Bleu, which is what one of the rider's friends would have looked like had he contracted [=GuldThunder=] (a ''Fenghuang''-themed Mirror Monster) rather than reject the offer.
** ''[[Series/KamenRiderFaiz Faiz]]'':
*** It had five riders taking five Greek Letters, leaving eighteen more. There was also a stageshow which featured Kamen Rider Alpha, Beta, and Gamma. The one downside is that, for the most part, [[spoiler:the wearer of the Driver has to be an Orphnoch. But that's okay, more potential to Sailor Earth it.]]
*** [[spoiler: Or, you could just be a human with a lot of Orphnoch DNA. Even then, Delta was implied to be usable by normal humans.]] The movie also introduces a means of giving normal humans a way of using the Kaixa gear, but at the cost of destroying the gear itself.
*** An official artbook depicts three unused Rider Gears: Neo-Alpha, Seeda (theta), and Pyron (pi). Neo-Alpha is fairly standard, but Seeda is designed for groups like police and emergency workers while Pyron is a civilian suit intended for sports and recreation.
** ''[[Series/KamenRiderBlade Blade]]'' is the only one outside of ''Kuuga'' to mostly avert this, as all four suits [[spoiler:and the Joker]] of its {{Playing Card Motif|s}} are already taken. The Movie Riders had to share a motif, an artificially created card called Kerberos, so there's where the "mostly" comes in. It's possible to have riders based off artificially created Undead/Cards.
** ''[[Series/KamenRiderHibiki Hibiki]]'' also has opportunity, giving existing character Akira the ability to transform into Kamen Rider Amaki, and other side characters becoming Oni. And there is more than one Takeshi branch and they date all the way back to Feudal Japan.
** [[Series/KamenRiderKabuto ZECT]] was constantly producing new Zecters. All one needs to do is think of an insect.
** ''[[Series/KamenRiderDenO Den-O]]'''s Imagin are based off Fairy Tales, so it's possible for one to make one based off an unused fairy tale. Kamen Riders in that setting are mostly made by bonding an Imagin to the suit, so you can also plop a pre-existing Imagin to make a new Kamen Rider. The Imagin Sieg was supposedly based on the story of ''Theatre/SwanLake'', which actually had a black swan EvilTwin named Oderjean to the protagonist, white swan Odette -- hence, [[http://i14.photobucket.com/albums/a323/aaronhong/Den-O%20Expanded%20Universe/KRDenOClawForm2.png this pic of Sieg's Evil Twin.]]
** ''[[Series/KamenRiderKiva Kiva]]'' has tons of lore waiting to be fleshed out, like the First Kivat. The official materials mention 13 Demon Races, of which we only see about half. The others are specifically named (including fantasy staples like Mermaids, Yeti, and Goblins), but aside from vague details, the door is left wide open.
** ''Series/KamenRiderDecade'':
*** Interestingly, the series gained a canon Sailor Earth in the form of Kamata/Kamen Rider Abyss, an original character made for ''Series/KamenRiderDecade'' who uses Mirror Monsters that were seen but not contracted in ''Ryuki''. [[spoiler:And for extra fun, he's '''also''' a Sailor Earth for ''Series/KamenRiderBlade'', being the Paradoxa Undead, which was named but never shown.]]
*** Also, ''Decade'' has Kamen Rider Kivala, empowered by a small, female Kivat-like bat-critter from the World of Kiva. She didn't ''operate'' in the World of Kiva, [[spoiler: being Natsumi and all]], but she's what a Sailor Earth looks like in canon. The Kiva story of ''S.I.C. Hero Saga'' seized this opportunity by giving Kivala a Kiva-canon partner, Megumi Aso.
*** There's also a plethora of Kamen Rider Decade/Diend clones out there that could grab up some remaining motifs, like a rider who can assume all the second riders' forms, etc.
*** With ''Zi-O'' establishing that the Decade riders now have cards corresponding to every rider up to Zi-O, there's still the open question of what the later riders' Final Form Rides would look like.
** ''[[Series/KamenRiderDouble Double]]'' is super easy, as nearly any Gaia Memory (and thus, any rider or dopant) can be made out of ''[[SerialEscalation any noun]]''.
** ''[[Series/KamenRiderOOO OOO]]'' had three Black Core Medals which were not used by Eiji. Several fan-arts created what would happen if Eiji used them for a combo. It's also very easy to make up entirely new sets of Core Medals: Just choose three animals that fit a theme. Rarely there are fan-created Greeed or even Kamen Riders ([[Film/KamenRiderXKamenRiderFourzeAndOOOMovieWarMegaMax Maybe both]]) to go along with new medal sets. As for full-fledged Rider powers, that's simple; since the Kogami Foundation made their own Riders (Birth and Poseidon) in-canon after studying Medals, and ''Movie War Megamax'' shows them planning on creating new Core Medals, fanfic writers are more than free to do the same.
*** Toei actually engaged in this themselves in 2018 with the release of the Complete Selection Modification[[note]]A series of high-end Kamen Rider prop replicas aimed at adult consumers[[/note]] version of [[TransformationTrinket the OOO Driver]]. All those unused Combos mentioned above (the Black Core Medals, Poseidon's Medals, and Kougami's Medals from ''Megamax'') were given [[http://bandai-a.akamaihd.net/bc/images/net-s_tokushu/20171211_oit_set_04.jpg official costume designs]] and transformation jingles.
** ''[[Series/KamenRiderFourze Fourze]]'' is perhaps the only Heisei era rider that has little to no exploitable template like the other Riders do, since the only three riders seen in the show are the main rider, the secondary rider (which is based on a different sort of powerset than Fourze's), and a movie-exclusive rider who cloned herself off Fourze.
** ''[[Series/KamenRiderWizard Wizard]]'' spells out what needs to be done to gain magical powers: someone needs to have magical potential in the first place, hit a DespairEventHorizon and cause that latent magic to form a monster called a Phantom, and then regain and hold onto hope quickly before the Phantom takes over your body and kills you, leaving it SealedInsideAPersonShapedCan. After that, there's just the matter of getting the belt and rings to go with it, which usually came from the White Wizard in-series. Or you can do what Kamen Rider Beast did and obtain a belt with a Phantom pre-sealed in it or bypass the entire thing by [[spoiler:making an artificial Phantom and implanting it inside you]]. In any case, one of the major bits is to choose a mythological creature to base your Phantom on, as that usually influences a character's Rider form or their SuperMode.
** ''[[Series/KamenRiderGaim Gaim]]'' manages to set up a formula right as it premieres.
*** Take a fruit/nut (e.g. Orange), take a kind of warrior (e.g. Samurai) and mash them together to make a Gaim Rider. There was originally a problem of ''how'' they get their hands on a Sengoku Driver, but midway through the series they started being mass-produced (if not distributed yet). Genesis Drivers are harder to obtain, as all of them are made and used by the villains, though at least two were handed down to Sengoku Driver users to act as upgrades. [[spoiler:Though if you wanna make a Rider, best make them before the end of Gaim, since they spelled out that the Lockseeds and Drivers have all but been destroyed save for two, though the Sengoku and Genesis Drivers are easy to reproduce and Lockseeds have been shown to be artificially made or be handed to by literal gods, and in one of the post-finale specials, there are remnants of Yggdrasil handing out Drivers and Lockseeds still]]. Specifically, there's Gaim's Jinber Arms; while Lemon, Cherry, and Peach variants were seen in the show, just using the official Lockseeds there's also potential for Jinber Melon, Matsubokkuri, and Dragonfruit (though the design of the suit and the action figures would seem to indicate that only Melon could even theoretically happen, the Lockseed toys still have sounds for Jinber Matsubokkuri and Dragonfruit).
** ''[[Series/KamenRiderDrive Drive]]'' has a pretty easy motif: vehicles. The main rider's based off a car, the second rider's based off a bike, and TheRival's based off a vehicle that's been modified. Not to mention that there's a lot of copying going around (the monsters can copy people and research notes have been used to make copies) and thus, you can easily have an EvilKnockoff running around.
** ''[[Series/KamenRiderGhost Ghost]]'' has an extremely easy motif: Dead people. Just pick a deceased person from history and you've got a power up.
** ''[[Series/KamenRiderExAid Ex-Aid]]'' zig-zags this trope. On one hand, the [[TransformationTrinket "Gashat"]] game cartridges are based on various video game genres, which makes new ones relatively easy to imagine -- just pick a video game genre (e.g. Platformer, Adventure), and imagine a name for the gashat; then, come up with the rider design and name. Or hey, just pick one of any number of real-life video games to base your character on; the show itself has some canon examples like ''VideoGame/PacMan''. On the other hand, the creation of Gashats and the number of Gamer Drivers that use them are both tightly controlled -- it's a plot point in the show when a Driver is damaged or stolen, as replacements can't be found easily. It's possible to bribe or blackmail the guy who makes them, but only if he sees you as a potential UnwittingPawn. You also have to be immunized against a deadly virus to use them safely.
** ''[[Series/KamenRiderBuild Build]]'' has an easy system for its power ups. Just pick something organic and something inorganic and there you go. [[spoiler:Then. if you want to have to involve the canon origins of the Best Match, justify why said inorganic can kill the organic.]]
** ''[[Series/KamenRiderZiO Zi-O]]'' has a blank cheque akin to Decade, but with the added caveat of [[EvilCounterpart Another Riders]], monstrous versions of the original Riders. Almost every main Heisei era Rider is accounted for, but only one or two extra Riders being made into Another Rider.
** ''[[Series/KamenRiderZeroOne Zero-One]]'' did some self-indulging by establishing that almost every Progrise Key can be used in any of the thirteen {{transformation trinket}}s. Designs have shown what'd happen if Zero-One were to use common Progrise Keys beyond his own set, but some take it beyond by making new Progrise Keys, which is easy to do given that one needs to think of an ability and an animal.
** ''[[Series/KamenRiderSaber Saber]]'' splurges on possibilities. The main Rider's belt uses up to three books at once, each categorized as "[[MythicalMotifs God Beast]]", "[[AnimalMotifs Animals]]", and "[[FairytaleMotifs Stories]]". On top of that, there are other Riders who use [[{{BFS}} different]] [[DualWielding ki]][[FuumaShuriken nds]] of [[SwissArmyWeapon swords]]. Throw in the fact that they also have ElementalPowers and you have a recipe for a plethora of Riders and forms.
** Monsters in the Kamen Rider franchise are easier to make. Especially with the Heisei era Kamen Riders, in which one can just select an animal motif that wasn't used before in that show. There are a few exceptions (like the Worms having only insect motifs, and rarely crustaceans, the Imajins, Zodiarts, and Phantoms needing to be based off a fable, constellation or mythological creature respectively), but the largest exception is, again, Blade, in which all 52 monsters are accounted for, though not all of them have appeared in the show, like the Stag Undead. Another large exception is Kamen Rider Drive, in which their 108 monsters are all accounted for, having at least one appearance in show (though they can get around the count via artificially made Roidmudes), though most of them are reduced to {{mook}} status, which means you could easily flesh them out and give them their own forms. However, it's easy in Double, where one just needs to think of a noun, and bam, instant Dopant.
** Some Rider series also make it easy for new forms to be created, especially with the later Riders with the exaggeration of MerchandiseDriven {{Transformation Trinket}}s.
*** Kuuga? His forms all came to be because Yuusuke was thinking "I need to be able to do X!" and when it got ''really'' desperate, his suit turns a new color, gains a power... [[MultiformBalance and loses one]]. To come up with new forms for him, you only need to think of a color that hasn't been used. (Red, white, blue, green, purple, black, and now gold -- Decade does it again! -- are taken. ''Anything else goes.'' You can also give "Rising" upgrades to your new forms, and give "Amazing" upgrades to new ''and old'' forms -- if there's Amazing Mighty, why ''not'' Amazing Titan? ''[[SerialEscalation Amazing Ultimate]]?'')
*** Den-O? Just add another Imagin, original or existing.
*** Double? You don't even have to invent new memories from whole cloth. What if Philip and Shotaro used another Rider's Gaia Memories? Or even Dopant Memories? Nazca and Skull are pretty popular choices for those [[spoiler:and Accel is even teased in the show, having Shroud's intention being to fuse Accel and Double's powers together]]. Canonically speaking, however, the non-existence of alternate Fang combos was explained by the Double novel, where it's mentioned that Shotaro's compatibility with the Joker Memory lets him put a leash on Fang's berserker tendencies; any other combo would result in Double becoming uncontrollable. However, in the ''Fuuto Detectives'' manga, [=FangTrigger=] does get used.
*** OOO? Core Medals can come in any animal motif, and the show even has created several that fall outside of the 21 Core Medals.
*** Also, Fourze introduces new Astro Switches via the "Hey, look what I whipped up today!" method, so new attachments for him can be easily introduced. However, there's a catch - it's established that there are only 40 Switches, all of which are accounted for, and the others are either usable by TheRival (Meteor and Meteor Storm Switches), abnormalities (Super Rocket and Super Drill Switches), or toys with little to no purpose in the show (Rider Switches).
*** Same with Wizard, except for rings and that there's no limit.
* Used to be common to insert a new survivor into ''Series/{{Lost}}''. In fact, the ''show itself'' inserted two entirely new crash survivors into the plot during season 3, linking them to several significant events in their sole flashback. Not so common after season 5, which [[spoiler:killed off every survivor that wasn't a main character, Rose, or Bernard.]]
* ''Series/CuteyHoneyTheLive'' has three girls based on three suits of cards. You can easily come up with a new one to represent clubs. In fact, the ''two other protagonists'' are a canon example of this: Honey's always had heart designs, but interpreting it as the ''suit'' hearts and coming up with diamond and spade girls with the same power is new.
* While this didn't really work during the show's run, the ''Series/BuffyTheVampireSlayer'' finale created hundreds of Slayers around the world. As a bonus, Slayers are always teenage girls (except for those who manage to make it to their twenties), and as MostFanficWritersAreGirls...
** Even before then, the show itself introduced a second "Chosen One" through LoopholeAbuse in the second season (Buffy drowned but was revived by CPR; that brief death activated her successor early), and with Faith basically off the show's canvas from season 4 to season 7, there's three years of canon where she's easily killed off and replace with an OC as required.
** ''Series/{{Angel}}'' firmly established that the Slayer being the sole warrior for humanity was a load of poppycock, with numerous individuals and organisations working against (and for) "vampires, demons and the forces of darkness", creating massive fanfiction potential.
* With the introduction of a Magic School in ''Series/{{Charmed|1998}}'' Season 6 this opened up mountains of possibilities for fanfic writers to create teenage witches who fight demons. Using additional Elders, Avatars and other such beings is quite easy too since only a handful of them received names on the show. Also due to the show's FantasyKitchenSink nature, plenty of fanfics introduce foes based on mythological creatures the show didn't use -- a German "Season 9" fanfic used Avalon, the Gorgons and the djinn for example.
** The canonical inclusion of a half dozen Halliwell descendants in the finale (who are basically blank templates) and the existence of time travel in-universe lend themselves to this, though the bulk of this type of fanfic focuses on Chris and Wyatt, the two descendants who canonically ''did'' travel back in time at various points to help the Charmed Ones.
* Happens many ways in ''Series/DoctorWho'' fics:
** Time Lords are established in canon as having multiple lives with individual personalities and appearances. Any Time Lord who has appeared in canon, including major characters like the Doctor, can effortlessly become an original character by regenerating them. Some examples of this:
*** During the Wilderness Years, future Doctors were quite fashionable. Some ''canonical'' examples include the Ninth Doctor played by Creator/RichardEGrant, the Ninth Doctor played by Creator/RowanAtkinson, the Doctor played by Creator/NicholasBriggs, the Doctor from the ''Literature/TimeHunter'' novella series who smokes and wears muttonchops, the Doctor used in some Short Trips stories who has an aging apolitical hippie aesthetic (wearing a camel coat and lots of pachouli), and the Eighth Doctor Virgin tried to create before the TV Movie came along, who would've been "played" by David Troughton. And those are just official and semi-official examples -- the fandom took it in even madder directions.
*** Coming up with original future Doctors, or alternative incarnations, based on actors the writer likes (or [[WhatCouldHaveBeen nearly got the role but never did]]) is a popular pastime. Big Finish's ''AudioPlay/DoctorWhoUnbound'' series was a series of one-shot audio dramas featuring various "national treasure"-type British actors having their turn at playing the Doctor.
*** Former showrunner Creator/RussellTDavies got in on the future Doctor thing in his [[Literature/DoctorWhoNovelisations novelisation]] of "Rose", introducing two Doctors somewhere after Thirteen -- one a tall, bald black woman wielding a flaming sword, the other an [[AmbiguousGender androgynous]] child in a hi-tech wheelchair with a robot dog.
*** In New series fics the introduction of the Chameleon Arch allows for any amount of Time Lord survivors hiding in the local populace.
*** The Master has even more scope for reinvention than the Doctor, to an almost limitless extent. He is stated to already be on his final incarnation by the time we first meet him as Roger Delgado, meaning ''twelve'' entire selves are unaccounted for on TV -- even if you choose to include the War Chief as one of his previous lives, as [[FanWank many people like to]], even if you include Big Finish's James Dreyfus Master, and even if you take seriously the implications that Missy is the first female incarnation of the Master, there's still a lot of room for invention. Even the Alex Macqueen Master used in the Big Finish audios is from the Master's second cycle of lives -- and we don't know how many lives deep s/he is in his/her second cycle[[note]]at least five (the Macqueen Master, the Jacobi Master, the Simm Master, Missy, and [[spoiler:the Dhawan Master]]), possibly six, if you count the Titan Comics incarnation[[/note]], or even whether it's the same length as the first (Rassilon in "Hell Bent" asks the Doctor how many regenerations they gave him, suggesting they're not bound to the old thirteen-lives limit any more). On top of ''this'', the final Master of the first cycle incorporates all the on-screen Masters seen throughout the Classic series and TV Movie, as that incarnation got around his inability to regenerate by stealing bodies (after being a [[{{Lich}} rotting corpse]] for a while), something he had no real practical limit to doing; the body the Master is in when he is executed by the Daleks at the beginning of the TV Movie was probably intended to be the body he took from Tremas, but, since the scene uses a very obvious FakeShemp instead of the usual Anthony Ainley, it ends up being ambiguous.
*** Romana had two on-screen incarnations. The first of these is heavily implied to be her first, and her second is suggested to be the one she fought the Time War in, heavily limiting her scope for reinvention, but official ExpandedUniverse material nevertheless has used multiple Third Romanas, particularly the one used in the ''Literature/EighthDoctorAdventures'' ([[ComicBookFantasyCasting based on]] Louise Brooks) and the one used in ''AudioPlay/{{Gallifrey}}'' played by Creator/JulietLandau. She's also unaccounted for in the New series as of yet even after the restoration of the Time Lords, except that she is no longer President...
** Since there is a non-canon human version of the Doctor played by Creator/PeterCushing, it's very common for fans to conceptualise a corresponding version of the Master played by Cushing's old Film/HammerHorror collaborator Creator/ChristopherLee. Due to the Cushing Doctor being ExiledFromContinuity (except for the short story "The House on Oldark Moor", which features several Hammer elements, but not this) this hasn't shown up in any official material yet...
** Several incarnations of the Doctor have been based on other people, with unexplained {{Criminal Doppelganger}}s and unremarked-upon recurring casting appearing in the Classic series a couple of times, and the New series coming up with clever internal explanations for YouLookFamiliar. This naturally means it's possible to have doubles of any of the existing Doctors show up, with {{Actor Allusion}}s of Doctors who played historical figures in other roles being especially common (particularly Creator/DavidTennant's version of Casanova, who often gets paired up with Rose). The fact that Creator/TomBaker's most famous casting before the Doctor was playing UsefulNotes/RasputinTheMadMonk has come up in a couple of books and audio dramas.
** In Classic series fics the Doctor would run into any amount of former classmates and Time Lord renegades who nicked their own TARDIS and legged it, semi-justified as it often happened in canon with the Rani, the Master, Drax, the Monk, etc.
** In fics for both eras the Doctor would land the TARDIS and pick up a totally-not-a-self-insert-at-all new companion (semi-justified, as the Doctor has almost certainly had more companions than the ones on-screen).
** For the vast majority of episodes, the only regulars are the Doctor and their one-to-three companions, featuring otherwise entirely new casts. Fanfiction can and has easily followed this formula.
** A lot of Time Lord [=OCs=] tend to have [=TARDISes=] that look just like the Doctor's police box shape, despite the reason for that being a broken chameleon circuit, working [=TARDISes=] being able to camouflage into whatever environment they materialize in. Other popular variants are the red London telephone booths or the red police boxes [[http://i244.photobucket.com/albums/gg26/robertpool/polisboxred.jpg like the ones that were in Glasgow.]] Red London buses are also fairly common, with Franchise/IrisWildthyme and the televised story "Planet of the Dead" both featuring Doctor surrogates with space Routemasters.
** The existence of a Black Guardian of Darkness and Chaos and a White Guardian of Light in Time was presented on screen as thoroughly dualist[[note]](see especially [[Recap/DoctorWhoS16E1TheRibosOperation "The Ribos Operation"]], [[Recap/DoctorWhoS16E6TheArmageddonFactor "The Armageddon Factor"]], and [[Recap/DoctorWhoS20E5Enlightenment "Enlightenment"]])[[/note]], but the "Guardian of X" formula nonetheless opened the way for other Guardians manifesting or protecting various facets of reality. Eventually this concept made its way into Extended Universe canon as a "six-fold god" that also included [[Recap/DoctorWhoS3E7TheCelestialToymaker the Celestial Toymaker]] as the Crystal Guardian, plus an Azure Guardian of the Quantum Realm, a Silver Guardian of Space and Matter, etc. Other writers scornful of this development jokingly proposed increasingly ridiculous additional Guardians, including a Jolly Green Guardian of Frozen Food, an Ochre Guardian of Puffins, etc.
* ''Series/{{Glee}}'':
** Many writers have yet to realize that adding a thirteenth member to New Directions throws off number balances, as there is usually an even split between boys and girls ([[SixthRanger Jesse]] didn't help that lesson sink in much either, even taking into account that his stay was temporary). As seasons pass, more members are canonically included.
** Thanks to ''Series/TheGleeProject'', many fanfic writers can cast contenders that didn't win as their [=OCs=], which more often than not are usually just the contestant with a different name (sometimes not even that) and slightly more [[GuyOnGuyIsHot hetero]][[GirlOnGirlIsHot flexible]].
* A common occurrence in the ''Series/{{Supernatural}}'' fandom is to create one or more new hunters, often a set of sisters. In the Supernatural universe, this isn't impossible, since hunters exist across the world. While some people create interesting additions to the universe, most are blatant self-inserts, especially because if these characters are female, the boys seem to fall for them by the end.
* Every now and then, ''Series/CriminalMinds'' will mention other, unseen [[TheProfiler BAU]] teams. One of them actually was showcased in the Season 5 episode "The Fight", which became the team for the short-lived spinoff ''Series/CriminalMindsSuspectBehavior''. Another was the JTF-12 team-featured as the targeted victims of the Ian Doyle arc of Season 6--of terrorist profilers that Emily Prentiss was a part of before joining the BAU. And the number of agents in the BAU isn't hard-coded, meaning creators could create another agent to join the team. Care must be taken to ensure the new agent fits in with the team and everyone has their proper roles story-wise, as the [[LoadsAndLoadsOfCharacters cadre of characters]] can get confusing for the audience if handled improperly.
* There are said to be 127 Elements in ''Series/SapphireAndSteel'', of whom four appear in the televised canon and two more in audio adventures. This leaves ample opportunity for fan writers; they need only pick the name of an element, gemstone or alloy that hasn't appeared in the show, and endow them with appropriate characteristics and powers.
* Being a prison drama, all you really need for an original character is a crime for them to have committed, but the ''Series/{{Oz}}'' equivalent of Sailor Earth is usually the first or only woman in Em. City (bonus if she's allowed because one or more of the other prisoners promises to protect her, and was wrongfully convicted, whether because she's actually innocent, or because she murdered a rapist. Bonus points if the other prisoners agree to protect her ''because'' they think she shouldn't have been found guilty.
* Wesen are pretty easy to add to the ''Series/{{Grimm}}'' canon. Pick an animal or a mythical creature, tack on a vaguely-related Germanic name and you're all set. New Grimms are even simpler, since anyone with a recently-deceased relative could discover they are one.
* ''Series/TwentyFour'' fans have it pretty simple: since there are so many CTU agents rotating in and out of the series through the show's run, simply have your CTU OC be on assignment somewhere else, which is why they're just meeting Jack Bauer or one of the others for the first time now. As the show has confirmed that there are other branches of CTU outside Los Angeles and even had Jack working with the New York one in the eighth season, this isn't too much of a stretch.
* The most common way to parody ''Series/TheRealHousewives'' is "The Real Housewives of [city where the writer lives that hasn't been given its own series]," where each cast member represents a different local stereotype played UpToEleven. Bonus points if it's a traditionally blue-collar city like UsefulNotes/{{Boston}} or UsefulNotes/{{Pittsburgh}} and the ladies are as trashy as can be.
* Fanfic authors for ''Series/UnnaturalHistory'' enjoy pairing up the already hinted Maggie[=/=]Jasper relationship, and writing in an OC (usually very well-travelled as well) to act as a Love Interest to Henry...when they're not writing Henry[=/=]Jasper.
* ''Series/UltramanRB'' has two variations. You can either go for:
** a) The R/B Crystals allow Rosso and Blu to augment themselves with different elements. Toy-wise, only four elements are available (Taro/Fire, Ginga/Water, Tiga/Wind and Victory/Ground), so you can use any other element and make a Fan Fic variant of elemental forms (eg. X/Lightning can turn Rosso into a green-colored lightning form).
** or b), if the user is not an Ultraman, it will transform into a variation of its respective Ultraman, just like [[CorruptCorporateExecutive Makoto Aizen]] using the Crystal of Series/UltramanOrb to become Ultraman Orb Dark. The result would be another copy of the Ultraman in R/B Crystal altered to reflect their user.
* Coming up with an OC for ''Series/CaptainScarletAndTheMysterons'' is pretty easy -- just pick a colour to give your captain. And since there are many colours, the possibilities are endless.
* There's enough wiggle room in ''Series/StrangerThings'' for one to create a new character who was experimented on by Hawkins Labs. 8 and 11 appear on the show, with 3 and 6 appearing in a tie-in comic, but that leaves another seven super-powered individuals who could potentially exist and meet the rest of the Party.
* Golden-Road.net, a fansite for ''Series/ThePriceIsRight'', is usually rife with people submitting their own original ideas for pricing games. When GSN's message board was active, they had members creating what they thought were improved versions of existing or once existing shows ("Password Ultra," for example) or TPIR pricing games.

[[folder:Music]]
* Neither Earth nor Pluto appear in Gustav Holst's ''Planets Suite;'' Pluto hadn't been discovered yet [[note]]and when it was discovered, Holst [[CreatorBacklash was so sick of]] ''[[CreatorBacklash The Planets]]'' [[CreatorBacklash upstaging his other work]] he didn't want to create it[[/note]], and Earth was, from Holst's astrological perspective, insignificant. Some amateur composers have created music to fill in these two gaps.
* For original rap groups in ''Music/HypnosisMic'' fics, all one needs to do is pick a Tokyo ward or popular Japanese city not covered by the series, give it three oddballs themed around the place, and throw them into the ring.
* Following Music/SiIvaGunner's ''King for Another Day'' event (a tournament where viewers vote for their favorite contestants, and the winner gets an entire day's worth of video game remixes themed around them) has inspired fans to come up with their own contestants. All you have to do is pick any fictional character and come up with a list of the types of music they'd be associated with (which includes music from the character's source material, but also music from media from the same genre or creator, or which is thematically appropriate for the character. Oh, and some contestants are teams, so another source of inspiration is to group up multiple characters with a common theme and come up with a clever name for the team.

[[folder:Mythology and Folklore]]
* Myth/KingArthur's Knights of the Round Table basically consist of a handful of characters who were in the original Welsh stories, plus a significant accretion of these type of characters, many of whom have been around for long enough that it's hard to imagine the stories without them. The most notable of these is Lancelot, who Creator/ChretienDeTroyes basically invented (links to an earlier Welsh figure are at best extremely tenuous).
* It's ''very'' easy to just create new Merry Men to follow Myth/RobinHood, and writers have been doing so for literal centuries.

[[folder:Pro Wrestling]]
* The most common plot trope in wrestling fics in the last few years is the introduction of a new WWE Diva (or in some very rare occasions, a new male wrestler). Understandable as there are always wrestlers coming and going. Either the girl is a legitimate fighter trying to be the second coming of Chyna and bring credibility back to the Divas division, or she's there to be the romance object of a male wrestler (the members of the Shield have been very popular targets lately). Often, these new wrestlers are the children or younger sisters of an current star.
** Sometimes, they vary the formula by having the new girl be a makeup artist, wardrobe girl, or a member of the tech crew.
* ''Kane'' was technically a Sailor Earth, as for awhile the WWE was desperately trying to find someone outside of Hulk Hogan, Randy Savage, or the Ultimate Warrior for The Undertaker to feud with for years after turning him face. ''Very'' few worked. Mankind became a counterpart character seemingly by pure serendipity. Kane was based on the early name for the Undertaker himself, given a backstory, and the two would go at it for years afterwards.
* One could argue that any long running character in any promotion who suddenly gains a rival who is somehow tied to that character's past is technically a Sailor Earth, regardless of whether that character is an ally or adversary. This has most recently been seen being utilized in ''Wrestling/LuchaUnderground'', who introduced Dante Fox, who would become an on again/off again rival for Killshot.

[[folder:Roleplay]]
* In addition to characters drawn directly from canon and fully-original characters from player-created themes, ''Roleplay/MahouMUSH'' provides the option to create original characters for canon themes. The ''Anime/MagicalGirlLyricalNanoha'' and ''Anime/HappinessChargePrettyCure'' casts especially boast a large number of original members due to how easy it is to explain new characters obtaining a Device or a [=PreCard=]. (The Administrivia/TropeNaming franchise has much fewer original cast members, although it does have a few -- none of them Sailors.)
* It's pretty easy to make a Nomad in ''Roleplay/AGameOfGods'' -= just pick a Greek Letter and a color, and voila, one Nomad.
* ''Roleplay/SuburbanSenshi'', given that the above-mentioned Sailor Moon and Doctor Who are part of the setting, has this in spades. Just for an example, there are Satellite Senshi based on each of Sol's planets that have moons.

[[folder:Tabletop Games]]
* This trope is ubiquitous in tabletop role playing games. Simply put, it is quite likely that regardless of genre or conventions, you are making a character who belongs to a pattern or group or class which is found throughout the gameworld. There are two main ways to do this: there could be classes (with or without levels), or there could be fictional organizations, clans, nations, and tribes the players affiliate with. (Both are frequently used together.)
A list of this would include almost every RPG that isn't an indie odd duck like ''TabletopGame/{{Fiasco}}''.
** An obvious example from ''TabletopGame/{{Dungeons And Dragons}}'', ''TabletopGame/{{Pathfinder}}'', and ''TabletopGame/{{Starfinder}}'': the class-and-level system gives your character the mechanics similar to the training and style of the rest of the setting. Additionally, every setting for any of those games comes chock full of nations, churches, organizations, trade guilds, monstrous hordes, secret societies, empires, armies, mercenary companies, and more that could serve to fill out the "fluffy" side of a player's brand-new Sailor Earth.
* This is outright encouraged by ''TabletopGame/{{Warhammer 40000}}''. Want to make up your own Space Marine chapter? There's canonically a thousand of them, and only a hundred or so have been so much as mentioned in canon, so go on ahead -- it's even perfectly valid to imitate an existing army due to the way successor chapters are created. There are also two Primarchs whose identities and abilities are unknown, seemingly for this trope. Similarly, there are a million worlds in the Imperium that your homebrew Imperial Guard regiment could originate from, the Eldar are so secretive that a previously unheard-of Craftworld suddenly appearing wouldn't be out of place, and the Tau are always settling new Septs. And so forth for Dark Eldar Kabals, Tyranid Hive Fleets, Ork tribes, Necron Tomb Worlds, Chaos Space Marine warbands... there's always far more of them than are ever actually detailed, and there's no shortage of players willing to make a neglected bit of background their own.
** The Chaos Codex takes this concept UpToEleven. Not only can you invent your own renegade chapter, you can also mix and match various legions and chapters into one army, with the justification that they are all united under one banner for some cause or another. This was originally the concept for the Red Corsairs, before they had their combat doctrine retconned.
** One of the biggest reasons why the 5th-6th edition ''Codex: Space Marines'' fluff by Matt Ward was hated was because it discouraged this, claiming that any chapter that wasn't just like the Ultramarines was bad.
** Matt Ward also, ironically, gave the Necrons more character by retconning their backstory so that each individual Tomb World had more characterization to it rather than just having a different color scheme. Previously all were controlled by the C'tans and had little free will, meaning that, apart from the paintjob, they were more or less identical (although that was sort of the point).
* Similarly, the same is encouraged to a lesser extent in TabletopGame/BattleTech. Major House regiments and Clan formations have been detailed in canon only in their basic composition (X number of mechs, Y number of Battle Armor, Z number of Aerospace Fighters, etc), allowing for easy insertion of a fan-created team. Also, Catalyst flat-out encourages players to make up their own new mercenary units, militia groups, pirates and other formations.
* ''TabletopGame/{{Exalted}}'' made room for not one, but ''two'' separate Sailor Earth Exalt types in their 2e Alchemicals splatbook. Not only did they open the possibility of Exalted with a natural affinity for [[PowerCrystal Adamant]], they also said that the Abyssal Exalted are [[TheUnchosenOne a mistake]] and not intended, leaving it open for a new Exalt type who has a "true" affinity to [[PoweredByAForsakenChild Soulsteel]]. These two types are only mentioned as vague possibilities -- nothing to suggest what they should be, if they exist. It was suggested in Dreams of the First Age that slain Incarnae existed once, and their Exalted went mad and were wiped from existence; this is one potential explanation of the above. However, given the source and given that it is generally considered to be quite feasible -- if far from easy -- to take on one's almighty divine patron and ''[[DidYouJustPunchOutCthulhu win]]'', the fan base has reacted to this idea with little approval.
** Perhaps a better idea would be to have the concepts they attuned to be one of the casualties of She Who Lives In Her Name's [[CosmicRetcon Three Spheres Cataclysm]]. These lost shards can only attune to people who embody, say, Flarg, but since no one can Flarg, these Shards are sadly not able to Exalt their chosen.
** On the Terrestrial side, while canonical Dragon-Blooded can only be aspected to the five Gaian elements (the Western four, plus wood), it's a common hobby to try to make Dragons of the five Underworld elements (ash, bone, pyre flame, blood and void) or the six Autochthonian elements (crystal, lightning, metal, steam, oil, smoke).
** Also for the Abyssals, the sourcebook says there are thirteen Deathlords, but only nine of them are described and given stats. This is explicitly so that Storytellers can create their own Deathlords.
** Introduced in 3e, the Exigents are the chosen of minor gods (there being gods of ''[[OddJobGods everything]]'' in Creation) who prayed to the Unconquered Sun for the permission to make their own Exalted when their domain was threatened, and used the divine fire of the Exigence they got if the Unconquered Sun approved (or if they stole it somehow), with the Exigence magnifying the god's own power in the chosen. This takes a lot out of a god though -- one sample Exigent got her powers from the god of a group of fields, who disappeared entirely after empowering her. Apparently the game designers were specifically invoking this when including them, as they wanted a way for players to introduce any Exalted they wanted without having to worry about adding a new group of the Princes of Earth into the game.
** If you ''do'' want to introduce a new type of Exalted, 3e has you covered there as well, since it introduces new Exalted like the Liminals and Getimians alongside the established types. (Admittedly, the big obstacle for fans in introducing new Exalted is coming up with a new charmset for them, which's never been an easy task.)
** 3e also introduces three [[LooseCanon optional Exalted]] for fans to flesh out: the corrupted, mind-eating Hearteaters, the haunted Umbral Exalted, and the reality-warping Dream-Souled. WordOfGod is that the Hearteaters are the Adamant-affinity Exalted -- it's not related to what they are, but to what they were before they fell.
** The Spoken, an extinct 3e Exalted type that lived undersea, open up possibilities beyond that of their existence: firstly, they're the first known non-human Exalted, previous editions having limited all forms of Exaltation to humanity, and secondly they confirm it is indeed possible for an Exalt type to be eliminated (from what's known of them, they were created Exalted, so it'd be entirely possible for something to happen that wiped them out and prevented more from being created).
** First Edition's ''Games of Divinity'' established at least 23 Primordials were imprisoned in Malfeas as Yozis, if not more, of which 15 have been recorded over the course of the game to date, leaving at least 8 for fan writeups. The number of Primordials who were killed and became Neverborn is unknown, leaving them up for grabs too. The number of Primordials who simply never participated in Creation, or left before the Primordial War, is also unknown. Then you have Second Edition's Infernal Charm Triumphant Howl of the Devil-Tiger, which allows the Infernal Exalted to become Primordials themselves. Basically, there are a ''lot'' of ways to introduce a new Primordial.
** Linked to the above in Second Edition was coming up with Charm sets for known Yozis for Infernals to access. This doesn't apply for Third Edition's Infernals, as essentially their entire setup is different, and they don't require drawing up an entire Yozi's Charmset to have Charms like a particular Yozi's.
** The Five Maidens are named for the classical planets (Mercury, Venus, Mars, Jupiter and Saturn), and some fans have taken the opportunity to postulate the existence of Maidens named for planets discovered later, helped by the books suggesting there might be additional Maidens.
** While we're on the Maidens, one of the possibilities 2e's Sidereal splatbook proposed for the identity of the Convention on Oversight was the Maidens' imprisoned ''brother'' Nox, an Incarna on par with his sisters. He became the jumping-off point for a popular fansplat, the Nocturnal Exalted.
* ''TabletopGame/{{Traveller}}'' has systems to generate new sectors of worlds and design new starships. The game has also designated the Foreven sector, right next door to the popular Spinward Marches sector, as a "GM's Preserve". No official material will ever be published about it beyond the star positions and a few worlds with minor details. Game Masters are encouraged to make up whatever they want to occupy that space.
* Since every {{Splat}} in the ''TabletopGame/NewWorldOfDarkness'' can have [[PrestigeClass more-specialized splats]] (Bloodlines in ''TabletopGame/VampireTheRequiem'', Lodges in ''TabletopGame/WerewolfTheForsaken'', Legacies in ''TabletopGame/MageTheAwakening'', etc.), it was painfully easy to crank out a new collection of Bloodlines, Legacies, etc., every couple of months. One book was even a collection of fan-created bloodlines.
* The TabletopGame/OldWorldOfDarkness usually includes some form of lost group. In ''[[TabletopGame/WerewolfTheApocalypse Werewolf]]'' it's the White Howlers, Croatan, and Bunyip; ''[[TabletopGame/VampireTheMasquerade Vampire]]'' has the Cappadocians, and in ''TabletopGame/ArsMagica'', something of a predecessor to ''[[TabletopGame/MageTheAscension Mage]]'' before its Dark Ages book came out, it was House Diedne, all mentioned but not present in the setting. It's a Sailor Earth player's field day. There's also the rules for creating new bloodlines in ''Vampire'', the different "lesser" Mage factions, the Siberakh werewolves (Silver Fang/Wendigo hybrids) and all the other werebeast species (cats, snakes, spiders, etc.), and so forth.
* A popular fan activity for both Worlds of Darkness has been coming up with additional splats to go alongside the official ones, such as ''TabletopGame/ZombieTheCoil'' (and parody splat ''TabletopGame/SenshiTheMerchandising'') for the OWOD and ''TabletopGame/GeniusTheTransgression'', ''TabletopGame/PrincessTheHopeful'' and ''TabletopGame/LeviathanTheTempest'' for the NWOD.
* In a crossover with literature, it seems like almost every group of ''TabletopGame/TheDresdenFiles'' RPG has an Autumn Knight. Not spring, always Autumn. Additionally, in the series there are three main vampire courts, the Black Court, the Red Court, and the White Court. A Jade Court has been mentioned in passing, and Billy brings up the possibility of there being different colored courts.
* ''TabletopGame/{{Scion}}'' is a game where AllMythsAreTrue, allowing fans to do their own writeups for gods and pantheons not covered in canon as potential Scion parents.
* ''TabletopGame/BattleTech'' has entire sourcebooks based on famous in-universe units and provides a metric ton of one-off short bios for various minor characters in the setting. Fans have alternately elevated certain characters to MemeticBadass status, put their own spin on minor characters, or written their own characters into existing units. Save for exceptionally out-of-place examples (no, no Inner Sphere mercenary unit aside from Wolf's Dragoons is known to have a Clan Omni before 3050) most fans tend to accept it at it comes. Alternatively, if you want to create your own Battlemech, there's entire design programs for that, as well as many stories of lost prototypes and one-off modifications to justify its inclusion in the setting.
* TheMultiverse of ''TabletopGame/MagicTheGathering'' is a very big place, with a wide assortment of planes, races and cultures. As such, creating a Planeswalker, species, or even an entire plane that can fit into canon is possible. The only exceptions are Phyrexians (who can't have a Planeswalker's Spark), undead, or beings made of mana like Angels or Demons.

[[folder:Toys]]
* ''Toys/{{Bionicle}}'' has plenty of humanoid species where only one or two named characters exist, and in order to expand on the main Toa cast all you need to do is choose any of the ElementalPowers, add a MaskOfPower and a weapon with optional attribute (especially since WordOfGod has it that there are dozens, if not hundreds, of Toa who don't feature in the main story). Or, you could try your hand with the numerous Dark Hunters, which are already a mixed bag of various species, powers and motives. The same applies for everybody in the ''Bionicle'' canon.
* For ''Toys/HeroFactory'', the successor line to ''Bionicle'', Franchise/{{LEGO}} created the Hero Recon Team. In-universe, the Recon Team is an intelligence force keeping tabs on the locations of villains. Out-of-universe, it's a program that lets fans create their own in-canon original characters and [[MerchandiseDriven buy toy versions of them]].
** Sadly, you can no longer purchase the figures. It is now simply a watered down creation tool, like the designer software.
* ''Toys/MonsterHigh'' is littered with fan characters. All one has to do is think of a famous monster, then come up with their offspring's profile. The trouble is, fans have a hard time telling appropriate uncanonical monsters (like, say, selkies or harpies) from more figurative monsters (like [[Franchise/{{Saw}} Jigsaw]] or ''[[Franchise/HannibalLecter Hannibal freaking Lecter]]'')...
* ''Toys/EverAfterHigh'':
** Most common examples are original characters for famous fairy tales that don't have canon ''EAH'' characters (especially ones with Disney versions). ''[[Literature/AlicesAdventuresInWonderland Alice in Wonderland]]'' original characters also pop up frequently due to several canon characters, as are ones for ''Literature/TheWonderfulWizardOfOz''. There are also [=OCs=] for more obscure fairy tales by Brothers Grimm, Hans Christian Andersen, and Charles Perrault, and even a few original characters for stories by more obscure fairy tale writers such as Madame d'Aulnoy and Andrew Lang.
** Disney-based [=OCs=] run rampant, and they are ''despised'' by much of the fandom, especially when the character designs closely resemble the Disney character. The worst offender has been ''WesternAnimation/{{Frozen|2013}}'' -- daughters of Elsa have popped up frequently. Other offenders include characters based on ''WesternAnimation/{{Pocahontas}}'', ''WesternAnimation/{{Tangled}}'', and ''WesternAnimation/{{Brave}}''.
** Among the plethora of fan characters are plenty based on darker fairy tales, generally created by members of the PeripheryDemographic.
** As the series has a broad definition of the term "fairy tale" [[note]]to date, aside of actual fairy tales, there are children who hail from folktales, fables, nursery rhymes, [[Theatre/SwanLake ballets]], [[Myth/ClassicalMythology Greek myth]], and even ''[[Theatre/KingLear a Shakespearean tragedy]]'', though that last case is currently exclusive to the book continuity[[/note]], it's very easy to push the boundaries with [=OCs=] while still staying true to the theme. You don't see too many fans introducing, say, the son or daughter of [[Myth/NativeAmericanMythology Coyote]], but it seems that just about anything is fair game in a franchise that gives you the likes of Myth/PaulBunyan's daughter or the daughter of a Joker Card. (Yes, as in [[PlayingCardMotifs the actual playing card]].)
** Some people take this to [[UpToEleven ridiculous extremes]] by suggesting that ''every'' story in the universe is a part of Ever After High's endless cycle and creating characters to match. For example, [[https://unmaskedagain.tumblr.com/post/618509910834102272/raven-leonard-queen-based-on-my-biodad-au-of this]] AU fic has the Evil Queen marry (and have Raven with) her generation's [[Literature/TheSagaOfDarrenShan Steve "Leopard" Leonard]], and a character tries to cover up an unexpected TeenPregnancy by lying that she's this generation's Series/JaneTheVirgin (with other characters dismissing the idea she could be Film/{{Juno}}).
* The original Toys/LEGODinoAttack line was simply about four guys fighting mutant dinosaurs. ''Roleplay/DinoAttackRPG'' added a full 237 additional agents, and that's just for the Dino Attack team itself. Other areas that lent themselves well to original characters included Toys/LEGOAlphaTeam, Toys/LEGOAgents, Toys/LEGOPirates, and more, with each theme also getting its own slew of [=OCs=] in its respective {{Play By Post Game|s}}.
* There's more than one fanmade Earth character for ''Toys/MilkyWayAndTheGalaxyGirls'', as that's the only planet in the Solar System that hasn't been anthropomorphized.
* ''Franchise/MyLittlePony'' has LoadsAndLoadsOfCharacters already, so a few more wouldn't make a big splash. Most G1-G3 fanworks revolve around [=OC=] ponies. Many were {{Winged Unicorn}}s, which wouldn't appear until G4 (''Friendship is Magic'').

[[folder:Video Games]]
* ''Franchise/{{Pokemon}}'':
** Fanfics involve aspiring Trainers just starting out on their journeys... and written in a way that makes the canon human characters look like incompetent chumps. On the other hand, that isn't difficult to achieve, as writing characters with ''sense'' puts them miles above the canon cast, or at least [[IdiotHero Ash]]. With the introduction of Trainer customization in [[VideoGame/PokemonXAndY Generation VI]] (thus meaning the {{Player Character}}s [[AuthorAvatar can now resemble the actual player]]), these types of stories have only become more prevalent. Bonus points if the trainer begins his/her journey with a Pokémon that's not a regional starter, usually an Eevee or Pseudo-Legendary.
** There's also an infinite number of newly introduced Team Rocket members. Those with a little more creativity just invent their own "Team Whatever" instead. Given that a new "Team Whatever" (or more than one, in some cases) is created in canon for every new region, this isn't surprising.
** Pokémon themselves are very easy for people to create. A few of them are creative enough, while most of them are not. A fan favourite would be made-up Eeveelutions. In one notable case, [[HilariousInHindsight fans came up with Leafeon, right down to the name, far before it was introduced in canon]]. One site somehow managed to come up with not only the name [[VideoGame/PokemonBlackAndWhite Team Plasma]], but nearly the same GOAL they had... in 2008. [[http://pokemonanrui.proboards.com/index.cgi Site here.]]
** As of Gen VI, numerous Pokémon have been given Mega Evolutions. There are literally hundreds of possible Mega Evolutions for existing Pokémon that don't already exist outside of fandom.
** [[VideoGame/PokemonSunAndMoon Generation VII]] introduced the concept of regional species variations with different appearances and types, which opened the floodgates for an effectively limitless amount of fan creations. Take an existing Pokémon, add a type or change its typing entirely, alter the design to match, and presto!
*** Even before regional variants were introduced, making breed variations of Pokémon based on different habitats or real life-species was common; for example, Bulbasaur with different species of flowers on their backs, or Houndoom based on different breeds of dogs.
** Another popular fan art topic is variations where a Pokémon whose father was a different species than the mother would take on different physical characteristics, ranging from different color pallets to changed physical characteristics.
** Creating a new region isn't entirely difficult. All one needs to do to create a convincing region is to take an existing country, or just a particular area of one, and add arbitrary routes and towns that follow a particular ThemeNaming.
** [[VideoGame/PokemonSwordAndShield Generation VIII]] introduces Dracozolt, Dracovish, Arctozolt and Arctovish, all prehistoric Pokémon restored from incorrectly mishmashed fossils. Creating more fossil mishmashes, or what the proper forms of these Pokémon should look like, is incredibly popular among Fakemon artists.
* ''Franchise/SonicTheHedgehog'':
** Countless numbers of new Freedom Fighters in ''Sonic the Hedgehog'' fanfiction, even though it isn't in a concept in the games. This is easier in fanfic concerning [[ComicBook/SonicTheHedgehogArchieComics the Archie comic series]], as there are any number of unnamed Freedom Fighter groups to work with.
** Boy, when they played ''VideoGame/SonicChronicles'', they'd probably have been shaking with rage or thinking "Oh, s/he came from this dimension where all the echidnas are." (Remember Shade?)
** Heck, many Sonic fan characters [[InNameOnly have nothing to do with the series at all]].
** There are plenty of never-before-seen hedgehogs who carry around an ''eighth'' Chaos Emerald running around.
** More than a few fan characters [[VideoGame/SonicAdventure2 were created by Professor Robotnik]] [[VideoGame/ShadowTheHedgehog on the ARK]] as "backup ultimate lifeforms."
** The official Sonic Twitter even posted [[https://twitter.com/sonic_hedgehog/status/726090715885756416 a chart to let you make your own Sonic name.]]
** With the announcement that ''VideoGame/SonicForces'' would allow players to create their own character, the possibilities for fan character artists and fanfiction writers has multiplied a million fold.
* ''Franchise/MegaMan'':
** The original ''VideoGame/{{Mega Man|Classic}}'' series easily allows for new Robot Masters or other new robot characters, who have [[ThemeNaming musical pun names]]. The ''VideoGame/MegaManX'' series simply uses animal (and, less commonly, plant) names to get the same result.
*** New [[VideoGame/MegaManZero Mutos Reploids]] and [[VideoGame/MegaManZX Pseudoroids]], by comparison, are considerably rarer, despite the implication that the former are quite abundant as protectors of the humans living in Neo Arcadia and/or elite soldiers of the [[EliteFour Four Guardians]]. While an assortment of animal- and plant-based characters like their predecessors, several Mutos Reploids have more of mythological slant to their designs than the majority of the non-humanoid Reploids in ''X'' [[labelnote:(for example...)]][[VideoGame/MegaManZero1 Anubis Necromancess, Asura Basura, Aztec Falcon, Hanumachine, Maha Ganeshariff]], [[VideoGame/MegaManZero2 Hyleg Ourobockle, Phoenix Magnion]], [[VideoGame/MegaManZero3 Childre Inarabitta, Cubit Foxtar]], [[VideoGame/MegaManZero4 Fenri Lunaedge, Mino Magnus, Noble Mandrago, Pegasolta Eclair, Popla Cocapetri, Sol Titanion, Tech Kraken]][[/labelnote]] though with much looser naming conventions as well; compare [[VideoGame/MegaManZero1 Blizzack Staggroff]] or [[VideoGame/MegaManZero2 Panter Flauclaws]] to '''[[VideoGame/MegaManZero3 Glacier Le Cactank]]'''. Meanwhile, Pseudoroids are more simply named (Name the Descriptionroid), with the caveat that the first letter of the Pseudoroid's name in ''ZX'' matches the Biometal fragment they carry (e.g. '''H'''ivolt the Raptoroid has half of Model H, '''L'''urerre the Abysroid has half of Model L). The Pseudoroids of ''ZX Advent'', who instead possess pieces of Model W, have no such restrictions (e.g. Chronoforce the Xiphosuroid, Vulturon the Condoroid, Queenbee the Hymenopteroid).
** In a similar vein, new scientists tend to come up, thanks to the series having so few of them (Drs. Light, Wily and Cossack). Occasionally, some of them do follow Cossack's [[ThemeNaming musical naming theme]] or even Light and Wily's [[NamedAfterSomeoneFamous famous intellectual first name theme]]. This is made fairly easy as many Robot Masters (such as in ''[[VideoGame/MegaMan6 6]]'', ''[[VideoGame/MegaMan7 7]]'', ''[[VideoGame/MegaMan8 8]]'', ''[[VideoGame/MegaMan10 10]]'', and ''[[VideoGame/MegaMan11 11]]'') were built by other, unnamed creators before Wily reprogrammed them, intentionally or, as in ''10'', inadvertently.
** There's also characters who are either the "real" last creations of Light or Wily, or prototypes of X or Zero, and were also sealed away in a capsule until discovered, some of which tend to have caused the "Cataclysm," the by-now {{Jossed}} Fanon theory that got rid of the Classic series characters.
** It's also popular in the Classic series to do this with [[AloofOlderBrother Proto]] [[AloofAlly Man]], whose [[MysteriousProtector infrequent]] [[BigDamnHeroes appearances]] [[TheStationsOfTheCanon in the canon]] mean there's plenty of spaces for fanfic writers to fill in for him.
** In ''VideoGame/MegaManX'' fan works, new characters are most often created as Maverick Hunters, like the canon protagonists. And since X is part of the 17th Unit, that frees up at least 16 other units of indeterminate size for fan usage--or at least it ''would have'' if [[VideoGame/MegaManX1 the]] [[VideoGame/MegaManX2 first]] [[VideoGame/MegaManX3 four]] [[VideoGame/MegaManX4 games]], [[AllThereInTheScript their instruction manuals]], and [[AllThereInTheManual supplemental materials]] didn't name seven of those units [[note]]4th Land Unit, 6th Armada, 7th Airborne Unit, 8th Armored Unit, 9th Special/Ranger Unit, 13th Polar Region Unit, 14th Special Unit[[/note]] along with a 0th Special Unit Zero commands after the events of ''X2''. The exact number of Hunters that comprised each unit prior to their post-[[VideoGame/MegaManX5 Eurasia]] disbandment is still unknown, as the only members seen outside of X and Zero defect and join Sigma's Maverick rebellion.
*** Since X and Zero are the leaders of the 17th and 00th units respectively, it's also common to create new characters to make up these units and show them functioning as teams. And ever since ''[[VideoGame/MegaManXCommandMission Command Mission]]'' showed that the Maverick Hunters have multiple ''headquarters'', like the Far East HQ shown in the game, opens up even ''more'' opportunities for other units.
** ''[[VideoGame/MegaManBattleNetwork Battle Network]]'' isn't hard to do this with either, being as there are several Classic Robot Masters and other robots that went unused by the end of the series, while ''Network Transmission'', ''[[VideoGame/MegaManBattleNetwork5TeamColonelAndTeamProtoMan 5]]'', and ''[[VideoGame/MegaManBattleNetwork6CybeastGregarAndCybeastFalzar 6]]'' bring in Zero, Colonel, and Iris--opening up possibilities for more ''X'' series-based [[{{Expy}} Expies]]. That's not even counting the possibility of random officials and/or other [=NetBattlers=] and their Navis made up wholesale, or giving an operator to [[KillAllHumans Bass]]. This can also work in reverse, as both ''Battle Network'' (''[[Anime/MegaManNTWarrior NT Warrior]]'' included) and ''[[VideoGame/MegaManStarForce Star Force]]'' have introduced [=NetNavis=] who do not have a canon Robot Master counterpart in the original series. On top of this, one Navi (Ring.EXE from ''[[GaidenGame Battle Chip Challenge]]'') is [[DistaffCounterpart the opposite gender]] of the Robot Master they're based on (Ring ''Man'' of ''[[VideoGame/MegaMan4 MM4]]''), opening up yet another door. As the ''[[VideoGame/MegaManLegends Legends]]'' series demonstrates, it doesn't stop there either: at least one Navi is influenced by a ''Legends'' character [[note]]Glyde.EXE, based on Glyde from ''[=MML2=]''[[/note]] and no less than four other characters have cross-series counterparts between ''Battle Network'' and ''Legends'' [[note]]Shu and her brothers Appo and Dah (''Legends 2'') > Shuko Kido and her brothers Atsu and Ty (''[=BN4=]: Blue Moon'' and ''[=BN6=]: Falzar''); Yaito of Pokte Village (''Legends 2'') > Yai Ayanokoji; additionally, Dr. Wily has another counterpart in the form of Wily, the Uptown boat house owner in ''Legends''[[/note]].
** Most ''VideoGame/MegaManZX'' [=OCs=] tend to be a character with a DoomedHometown discovering a Biometal that's based on other ''Mega Man'' characters, if not Model O. As the ''[[VideoGame/MegaManZero Zero]]'' series doesn't offer too many candidates to base a Biometal on beyond [[VideoGame/MegaManZero2 Elpizo]] and [[VideoGame/MegaManZero4 Craft]], fans tend to turn to the original and ''X'' series for inspiration.
* ''Franchise/KingdomHearts'':
** New Keyblades get handed out like lollipops in the ''KH'' fanfic 'verse, so Sora and Company start running into new worlds and new Keyblade masters with such alarming frequency that you have to wonder how the original worlds were even lost in the first place. However, the series states that [[WorldSundering once]] there ''were'' thousands of Keyblade wielders, and [[UniquenessDecay more do keep popping up]], so there's precedence for this.
** Some fanfics of ''Kingdom Hearts'' may actually show an ''entirely'' new Organization surfacing from all that was ever left of the old one. Considering the "Twenty Years later, a new disaster causes a group of people to lose their hearts and create Nobodies" situation is, in theory, highly possible. [[spoiler:This is entirely canon. ''[[VideoGame/KingdomHearts3DDreamDropDistance Dream Drop Distance]]'' states Master Xehanort is reviving Organization XIII using himself as the leader and various incarnations of himself and other beings corrupted by him as the members, with this new Organization serving as the main villains of ''VideoGame/KingdomHeartsIII''.]]
** It used to be fairly common in fics to see a character being introduced as [[OneExtraMember the fourteenth member of Organization XIII]]. Such characters became fairly easy to name as well, as members of the Organization's names are [[SignificantAnagram anagrams of their original names]] with [[LetXBeTheUnknown an "X"]] thrown in somewhere. Such fics were often mocked, considering they're called Organization ''Thirteen''. But then ''VideoGame/KingdomHearts358DaysOver2'' came out, a midquel which revealed the Organization had actually ''had'' a fourteenth member, and {{deconstruct|ion}}ed the entire concept.
** Chances are you'll find new types of Heartless and Nobodies in fanfics. Given that most of the Nobodies are based on a ''Franchise/FinalFantasy'' job class in name and abilities, creating new types is fairly simple. Besides, it is strongly suggested that there were five more classes of Nobodies that were never seen. Discounting the Twilight Thorn and Gummi Ship enemies, ten types of Nobodies were in ''VideoGame/KingdomHeartsII'': two common types (Dusks and Creepers) and one type of minion for each of the eight Organization members still alive at the beginning of the game. There is no logical reason why the five who were killed [[VideoGame/KingdomHeartsChainOfMemories at Castle Oblivion]] wouldn't have had their own minions. ''VideoGame/KingdomHeartsIII'' would eventually reveal two of the "missing" types: Reaper (belonging to [[spoiler:Marluxia]]) and Ninja (belonging to [[spoiler:Larxene]]). The other three remain unaccounted for, even with [[spoiler:Vexen ([[TheMole sort of]]) showing up as a reserve member for the True Organization]].
* ''VideoGame/RatchetAndClank'' is so loosely written in canon with any number of worlds and characters that he can encounter in any given game that it's a given that you'll have to invent a couple characters. But any OC that pops up as a Lombax is an automatic Sailor Earth!
* In ''VideoGame/{{Portal}}'' fics, there's no effort needed to come up with a background for an OC, what with the thousands of test subjects, scientists, and robots who work at Aperture. Having them survive the events of the second game is a bit trickier, but still manageable. It's not hard to imagine someone other than Doug Rattman escaping and laying low in that facility or staying asleep in some forgotten cryogenic chamber (it's completely like Aperture to lose someone like this). It was also popular for [=OCs=] to come from [[spoiler: those humans you find in the Cooperative campaign, until the DLC revealed that [=GLaDOS=] killed them all]]. Then there are all those other alternate dimensions from the Perpetual Testing Initiative DLC...
* As noted in General, it's trivially easy to add a "baddest of the badass" [[CoolSpaceship new ship]] in any game or series based in space, particularly when there's such a potentially huge war zone where only relatively small slivers of it have been revealed, like in the ''VideoGame/WingCommander'' or ''Franchise/StarWars'' game universes.
* ''Franchise/{{Halo}}'':
** In the franchise's early days, less than half of the original 30 or so [[SuperSoldier Spartan-IIs]] were named. This made creating a new Spartan character as easy as picking a first name and a three-digit number, as long as you didn't expect people to accept your Spartan surviving [[EverybodysDeadDave the Fall of Reach]] -- virtually every survivor of that battle is canonically accounted for. Eventually, most of the Spartan-[=IIs=] were given names, which you'd think would mean the end of this trope. However, this has been balanced out by the reveal that some of the 45 or so Spartan-II trainees who had allegedly "washed out" did actually later become full Spartan-[=IIs=] themselves; when combined with media also revealing that not every Spartan-II was even ''at'' Reach when it fell, this still leaves plenty of room for Spartan-II [=OCs=].
** An even more fruitful source of fan-made Spartans is the Spartan-[=IIIs=], hundreds of which were produced; Gamma Company is a particularly popular source, as there seems to have been at least 300 of them left when the war ended. ''Literature/HaloEvolutions'' and ''VideoGame/HaloReach'' added to this by revealing that a number of Alpha and Beta Company [=Spartan-IIIs=] were secretly transferred to more elite units like Noble Team, which meant that they weren't killed on suicide missions by their early teens like all but two of the other Alpha and Beta [=IIIs=]. In fact, nowadays you're more likely to come across a Spartan-III OC rather than a Spartan-II one. It could even be argued that ''Literature/HaloGhostsOfOnyx'' introduced the [=IIIs=] specifically with the intention of allowing more canon Spartan-centric stories to be written.
** And now we have the Spartan-[=IVs=]; not only are there hundreds of them, but they're all adult volunteers who come from virtually every branch of the UNSC military. The creative potential is endless.
** There's also a surprising aversion; while ''ARG/ILoveBees'' claimed that there were ''multiple'' classes of Spartan-[=IIs=], subsequent canon has mostly ignored this, and the fans have mostly followed suit (though there are a few exceptions).
* ''Franchise/TouhouProject'':
** In canon, {{youkai}} apparently outnumber humans by a fair margin. If the sheer diversity of ''those'' in Japanese mythology isn't enough fodder for the fans, races like the Celestials, the Yama and the Kappa only have one named representative ''each'', allowing fans free rein to make their own. Of course, the franchise has the unique distinction of being largely {{Fanon}} anyway.
** Why limit ''Touhou'' [=OCs=] to ''Japanese'' mythology? Canonically, the vampires, psychically-produced poltergeists, resident CuteWitch, and fairies all have strong Western influences, and there [[EpilepticTrees may or may not]] be a Chinese dragon in the mix as well.
** This isn't even limited to youkai. Aside from Keine, Akyuu and Kosuzu none of the residents of the Human Village are known (and the first two of those aren't exactly human anyway), and it's canon that humans from the Outside find themselves in Gensoukyou on a semi-regular basis. The latter in particular is incredibly fertile ground for {{Self Insert Fic}}s.
** It's also notable that Touhou characters often have absolutely [[SuperpowerLottery absurd powers]], making it paradise for someone who wants to create a superpowerful character without abusing canon too much. [[PersonOfMassDestruction "Destruction of anything and everything"]] and [[RealityWarper "manipulation of boundaries"]] are legit powers. Honestly, the more ridiculous your character's power is, the better. Bonus points if it sounds innocuous at first but turns out to have ludicrous applications.
** Some of the fan-produced characters have acquired such a popularity that they might as well be canon. Notably Mitori Kawashiro, the sister of the Kappa girl Nitori, whose power is to prohibit anything (in good ''Touhou'' fashion, this is difficult to wrap your head around and potentially absurdly broken). Mitori has her own fanmade theme and appears in a fanmade game.
** Another relatively popular fan character is the Sendai Hakurei no Miko ("The Previous Generation Hakurei Shrine Maiden"). Originally a ''VideoGame/{{MUGEN}}'' Touhou character who was notable for being a pure close-range physical fighter (even when compared to Hong Meiling) among the cast of long range projectile fighters, artists and writers picked her up and fleshed her out as a no-nonsense shrine maiden who prefered to beat her opponents to a pulp with her own fists, as a result sporting a modified Miko outfit with a LeotardOfPower that shows off [[CoveredInScars her scar-covered body]]. Her relation to Reimu varies, from mother to a distant ancestor, or just an unrelated woman who previously held the position of the Hakurei Shrine Maiden.
* ''Franchise/{{Persona}}'' fanfics will probably involve someone else learning to use a Persona. Original stories are pretty common, especially ones that aren't set in Japan. [[note]]Throughout the entire series so far, only ''one'' major character, [[VideoGame/Persona2 Lisa Silverman]], isn't ethnically Japanese, and she had been raised there her entire life anyway.[[/note]] Or another member of [[VideoGame/Persona3 SEES]]. Or an employee of [[VideoGame/{{Persona1}} SEBEC]]. Or another member of [[VideoGame/Persona2 the Masked Circle]] or who survived [[VideoGame/Persona4 the fight in the TV]]. Heck, even an extra member for [[VideoGame/Persona5 The Phantom Thieves of Hearts]]. As for new Personas, just pick [[TarotMotifs a card from the major arcana]], a mythological/historical figure, and an assortment of powers. Bonus points for a [[OurMonstersAreWeird bizarre appearance]].
* ''Franchise/FireEmblem'' is naturally rife with this, as all of the games are war stories. If it doesn't involve adding an original character into the army, it's usually a prequel or sequel telling about barely-told events and histories, with [[VideoGame/FireEmblemTheBlazingBlade Renault's past]] or [[VideoGame/FireEmblemPathOfRadiance anything regarding the Branded]] being very popular subjects. And since [[VideoGame/FireEmblemAwakening the 3DS]] [[VideoGame/FireEmblemFates installments]] ([[VideoGame/FireEmblemGaiden remakes notwithstanding]]) have [[PlayerCharacter character avatars]] and the [[TimeTravel Outrealm]] [[TheMultiverse Gate]], there's even more fertile ground, with EpilepticTrees abound.
* ''Franchise/TheLegendOfZelda'' fanfic writers frequently invoke this trope:
** Remember the UrbanLegendOfZelda that there's actually a fourth [[MacGuffin Triforce]], which balances and completes the other three? This (very unlikely) theory is often taken as premise for fanfiction and along comes a fourth golden goddess ''and'' a fourth Triforce-bearer, usually female, SoBeautifulItsACurse and related to Link in some way. Or the fourth Triforce goes to an AuthorAvatar, who was [[TrappedInTVLand "sucked into the game,"]] another very popular premise in the world of ''Zelda'' fanfiction. For a ''"good"'' example of this, see ''FanFic/MyInnerLife''.
** There's also "Kasuto" in ''[[VideoGame/TheLegendOfZeldaOcarinaOfTime Ocarina of Time]]''. To elaborate, every town in ''VideoGame/{{Zelda II|TheAdventureOfLink}}'' had a character in ''Ocarina'' named after it, with the exception of Kasuto. This has occasionally overlapped with the fourth Triforce bit.
** On the subject of the fourth goddess bit, it turns out in ''[[VideoGame/TheLegendOfZeldaSkywardSword Skyward Sword]]'' that there ''is'' a fourth goddess. Of sorts, anyway. When the golden goddesses of old departed from the world they created, they entrusted the Triforce to a goddess named Hylia for safekeeping. However, while Hylia is a revered and powerful deity, she is depicted as being of a lesser status compared to the likes of Din, Nayru, and Farore.
** Strangely, very few authors take the most obvious path for introducing a new Triforce holder. Canonically, Ganon is not the person meant to get the Triforce of Power in the event that it is split by an unbalanced heart; he keeps getting Power because he's nearly always responsible for the Triforce splitting in the first place and that piece is the one that embodies his desires. Canon implicitly includes a third chosen one who would complete a PowerTrio with Link and Zelda, but is prevented from doing so by Ganon's repeated thefts of his or her intended Triforce piece. Since this individual has never been identified in the games themselves, they are perfect OriginalCharacter fodder, but very few fan authors take advantage of it.
* ''VideoGame/TeamFortress2'' [=OCs=] tend to come in the following flavors:
** Each [class] is simply one of many who serve in that role, and while their general appearance and personality tends to fit the archetype of that class, they have their unique quirks. (The most famous of this type is ''Webcomic/CuantaVida'', though in that comic the occasional character has an "inappropriate" personality that is either PlayedForLaughs or PlayedForDrama.)
** A female version of the class, either as part of an all-female squad rival to Red/Blue or on the squad as the first female whatever (or one of the occasional female whatever), with the 1960s sensibilities of their potential teammates are either entirely ignored or exaggerated to the point of HeManWomanHater.
** The (currently nonexistent) tenth class or some other type of RED/BLU/Mann Co. staff not present in the game but implied to exist as a vast network of operatives in the supplementary comics. (Notably, the Administrator started life as such a character before she became AscendedFanon, and Grey and Olivia Mann can be seen as parodies of such character types.)
* This is very common in ''VideoGame/Left4Dead'' fanfic, as many writers create a new Special Infected which makes the Tank look like a Muscular Chipmunk, or adding a 'survivor' who caught the Green Flu only to gain all the superpowers and none of the flesh-hungering side effects (the ''only'' precedent for this sort of thing in-canon is that the playable Survivors can take absurd amounts of damage -- at least below Expert difficulty -- and are themselves carrying TheVirus, of which there has been no official correlation). Alternatives include fleshing out the unseen characters of "Chicago Ted" or Ellis' buddy "Keith", since there is literally nothing canon revealed about either of them, other than that the former is apparently "king of the zombies" and the latter [[NighInvulnerability has already survived several absurd predicaments]] ''before'' said virus was introduced.
* ''Franchise/SuperMarioBros'' is subject to this, due to how little several settings or groups are featured or elaborated upon, mostly Bowser's troops. Specific examples include:
** Sarasaland. The Mushroom King. Beanbean Kingdom. The Shroomers. More plumbers. Worlds 1 through 8. The Yoshis. Subcon. It's really too easy. The world building is there, we're just not given all of it.
** It's common for someone to create a whole team of ''VideoGame/PaperMario'' partners. Simply dress up some of the series signature mooks (Goombas, Koopas, Boos, maybe throw in a Toad or Yoshi or original creature in there), make sure they have the ability to explode, jump gaps, disappear, etc., and a new team is set.
** It is given some elaboration in ''VideoGame/YoshisIsland DS'', which states that there are a total of seven people as powerful as Mario and Luigi, and they're all named. That doesn't stop anyone.
** Creating a SixthRanger for the [[VideoGame/SuperMarioRPG Axem Ranger]] to follow the [[Franchise/SuperSentai pattern they are]] [[Franchise/PowerRangers a parody of]] is also common. Usually Blue; Purple isn't unheard of, though. In one example, [[SixthRangerTraitor the Axem Blue turned out to be Geno]].
* It's extremely easy to make new copy abilities for ''Franchise/{{Kirby}}'', given how each canon installment adds new copy abilities that either become staples of the franchise or become one-shot abilities.
* It's easy to add anyone into the ''Franchise/SilentHill'' Universe without major canon issues, so you can expect that a lot of those people are going to be self-insert/wish fulfillment characters.
* ''Franchise/DragonAge''
** ''Very'' easy to do in ''VideoGame/DragonAgeOrigins''. Despite the fact that the box says the main character is among the last Grey Wardens, Alistair mentions that this is only true in Ferelden, the game's setting. Speaking to him brings up the mention that there are Grey Wardens all over the world and in neighbouring countries -- a Sailor Earth could simply be from another part of the world. ''Ridiculously'' easy to do for an ElsewhereFic. Indeed, the expansion pack, ''[[VideoGame/DragonAgeOriginsAwakening Awakening]]'', uses this very setup -- if you choose to start a new character rather than import the hero from ''Origins'', they will be a senior Warden from Orlais sent to help replenish the ranks of the Grey Wardens in Ferelden.
** A blink-and-you'll-miss-it InUniverse [[InvokedTrope invocation]] occurs in ''VideoGame/DragonAgeInquisition''. A major part of the setting's lore is [[RuleOfSeven seven]] Old Gods who take the form of High Dragons. A constellation seen early in the game mentions that it was depicted as a dragon even in [[TheMagocracy Ancient Tevinter]], which is very inconsistent with that period's iconography practices; why would Tevinter devote a constellation to dragons in general when they worshipped seven specific dragons? This led to a scholar suggesting that the Draconis constellation originally represented an eighth Old God that was stricken from the record. The implications of this is a subject of debate in the fandom.
* In ''VideoGame/{{Borderlands}}'', a Sailor Earth could simply be another vaulthunter like the four playable characters, complete with a new gadget, power or physical ability. Better yet, it could be an entire team of four new vaulthunters, as they always seem to travel in groups of four. Bonus points if one member is one of the 5-6 other "Sirens" like Lilith and Maya.
** Other possibilities involve creating new characters tied to the prolific weapon manufactures found in game, or creating new weapon manufacturers entirely (though this is a little more convoluted--the gear creation system on which ''VideoGame/{{Borderlands 2}}'' and ''VideoGame/BorderlandsThePreSequel'' is based has a number of very specific rules to follow.)
* ''VideoGame/MetalGear'' has the three Snakes: Solid, Liquid, and Solidus. The absence of the most obvious third entry in the [[ThemeNaming matter-based naming cycle]], Gas Snake, makes him an easy choice for this. Plasma Snake would be a somewhat close second. However, Solidus Snake fills the theme roll of Gas Snake. [[note]]Solidus is a chemical term for the line on a pressure/temperature diagram that marks the phase transition between a solid and liquid.[[/note]] [[Webcomic/TheLastDaysOfFoxhound Bose-Einstein Condensate Snake, however, has not had much support.]]
* ''Franchise/MassEffect''
** The general concept of Council Spectres alone is ripe for fan-made characters. Outside of Shepard, Nihlus, Saren, Tela Vasir, Jondum Bao, and [[spoiler:either Kaidan Alenko or Ashley Williams, depending on who you let live in the first game]], the Spectres in general have been ''barely'' given any attention in games or in the ExpandedUniverse, with the exception of [[AscendedMeme Blasto, the first Hanar Spectre]].
** The various merc groups and even C-Sec employees offer more options for this trope, too.
* Fan characters in both ''Franchise/SpyroTheDragon'' canons are popular, ranging from simply other dragons to another survivor of Spyro and Cynder's Year of the Dragon. Other popular topics are a Wind Guardian or a replacement for [[spoiler:Ignitus]], as well as Purple Dragons between Malefor and Spyro.
* ''VideoGame/DissidiaFinalFantasy'' is an IntercontinuityCrossover bringing together thirty ''Franchise/FinalFantasy'' characters from all over the series to fight on behalf of the gods Cosmos and Chaos. ''Dissidia'' and its prequel ''Dissidia 012'' explain these wars occur as a cycle--when one side loses they get their memories of the battle erased, and are revived to fight again. The two games cover the 12th and 13th cycles, and the 13th one of the last. That leaves Cycles 1-11 unseen, with no real information on who was fighting in them, for which side, and what happened that they didn't make it to future cycles. As a result it's common for fanfiction to be set in one of those earlier cycles with new characters drawn into the war, and from there you can take the story anywhere you want it to go.
* A very easy way to make a ''Franchise/MortalKombat'' fan [[XtremeKoolLetterz kharakter]] would be to take a kolor that ''hasn't'' been used by a ninja yet, and make your very own HighlyVisibleNinja for that kolor.
* ''VideoGame/{{Doom}}'' gives plenty of wiggle room for new varieties of hellspawn from [[FanNickname Doomworld]], as well as loads of [[FanSequel custom-made]] [[MissionPackSequel megawads]]. In the case of the former, though (possible via Dehacked or by using features of [[GameMod a certain few sourceports]]), it is possible to create [[PaletteSwap recolored enemies]], [[UndergroundMonkey completely different versions]] ([[GoddamnedBats In most cases, either more annoying]] or [[DemonicSpiders far more lethal]]) versions of weaker enemies. The Zombieman/Shotgunner in particular has been reskinned to carry just about every weapon the player can wield. Certain monsters, such as the [[MascotMook Cacodemon]] or any of the [[DegradedBoss UDoom endboss enemies]] have quite a few variants of them, to say the least. However, there are also a handful of ''actual'' original DOOM monsters out there.
* The ''VideoGame/PhantasyStar'' series (prior to the ''Online'' games, anyway) has the Espers, and the Hunters: Espers are a race of magical, reclusive people with magical abilities who all come from the same Mansion, Hunters are monster-slaying bounty hunters who operate out of a Guild. There's also the Lutz lineage; Rune is the Fifth Generation Lutz, which means there were three others before him, and presumably, whoever comes after him will be Sixth. All original characters for the series fall into one of those three camps.
* One of the races in the ''Literature/LandOfOz'' series are the phanfasms, creatures who have human bodies but the heads of various animals. In the flash game ''VideoGame/EmeraldCityConfidential'', one of the characters is revealed to be a double agent for the phanfasms. The main character, Petra, is confused because he looks completely human. He points out that phanfasms have animal heads, and humans are animals, are they not? [[spoiler: He was wrong, he was a human raised by the phanfasms. But he raised an interesting point that's similar to this trope]].
* It's common in some ''VideoGame/ValkyrieProfile'' fan circles to introduce other Valkyries, usually taken directly from Norse Mythology. Brunhilde is particularly popular. This is in spite of the fact that there are canonically only three due to being combined with the Norns and being a very literal FreudianTrio. Despite this, ''[[VideoGame/ValkyrieProfile2Silmeria Silmeria]]'' did introduce a possible mechanism for other Valkyries to be introduced, not that fans take advantage of it.
* When it comes to suggestions for ''VideoGame/BloonsTowerDefense'', the most common "new bloon rank" suggestion given is a new MOAB class bloon containing 4 of the current highest-ranked bloon. For reference, the BAD is the current strongest bloon.
* ''VideoGame/CookieClicker'' has various suggestions fall under this.
** As of April 2014, element related building suggestions are common, despite the fact we have Antimatter Condensers and Prisms. Double if they are described as "condensers", "converters", or any word of the like. However, as of May 2014, they thankfully died out.
** There are many "new best building" ideas on the forums, but it is slightly justified because of the fact it's one of the more obvious suggestions to make.
* An in-game example: in ''VideoGame/Disgaea2CursedMemories'', Rozalin becomes outraged that the Prism Rangers only have five colors represented, not seven, and after beating them demands that they fill the missing positions (which does finally happen in a special map later on).
** ''Franchise/{{Disgaea}}'' fanfics that center on either generic units or original characters can be easily written, as there are stated to be a countless number of Netherworlds. For the generic units, they can also have personalities that wildly differ from the norm, as Reincarnation is a mechanic in the series.
* A widely underused example in ''VideoGame/TheKingOfFighters'' comes from the moderately obscure ''EX'' titles, [[AlternateContinuity which branch off from]] ''KOF [='97=]'' in place of the NESTS Chronicles that began in ''[='99=]''. Over the course of the two games, players are introduced to the members of the Ten Sacred Treasures (based on the debatably historical artifacts of the same name reportedly housed in Isonokami Shrine). ''EX'' marks the debut of Moe Habana, with the sequel bringing in Reiji Oogami, Jun Kagami, Miu Kurosaki, and Sinobu Amou, but only Moe, Reiji, and Sinobu have their treasures revealed. Strangely, the members of the Three Sacred Treasures (Kyo Kusanagi, Iori Yagami, and Chizuru Kagura) are counted among the Ten's ranks despite possessing [[PublicDomainArtifact the Imperial Regalia of Japan/Treasures of Amaterasu]], which are theorized by some to be the inspiration for the Ten Sacred Treasures due to overall similarities between the two legends. Presumably, if the ''EX'' story wasn't LeftHanging, the remaining two members would have made an appearance, and the oddity mentioned above means there actually should be ''five'' unseen characters.
* A good number of ''VideoGame/NintendoWars'' fanfics involve a new Commanding Officer joining one of the nations to help them in battle, with his or her own day-to-day ability(s) and CO Powers. Some fanfics may also put their [=OCs=] in a brand new nation, with a name following the usual nation naming trend of a colour, followed by a celestial object.
* It's become quite popular to think up new animatronic characters for ''VideoGame/FiveNightsAtFreddys''. Basically you just need to think of an animal, give them a cute-sounding name (canonically they are all [[AlliterativeName alliterative with their species, or last name if they have one]], but this isn't always followed with fan characters), and make them into a creepy anthropomorphic robot. Optionally, they could also be given their own musical instrument to play in the band, or some other specialized role at the pizza place. Some people try to justify their characters' absence in the original game by giving them backstories involving being taken out of active use; others have gone so far as to make up an entirely new restaurant competing with Freddy's for their characters to inhabit. As later games in the series have introduced different variations on the existing characters ("toy", "withered", "phantom", "nightmare", "funtime", and "scrap"), fans have often given such variations to their own characters.
* It's fairly easy to make your own ''VideoGame/HollowKnight'' Vessel OC. Just create a unique mask shape, give a color for the cloak, and lastly a brief backstory [[spoiler:on how they managed to escape The Abyss.]] Most fanfictions involving OC Vessels have them either being [[HeroOfAnotherStory a hero of another story]], interacting with the other [=NPCs=] around Hallownest or even appearing in other kingdoms.
* ''VideoGame/{{Undertale}}'':
** While ''VideoGame/{{Undertale}}'' [=OCs=] can theoretically look like anything, given the diversity shown by the game's own [=NPCs=], the ThemeNaming displayed by Sans and Papyrus [[spoiler:(and supposedly Gaster)]] has led many people to specifically make new skeleton characters named after the fonts in which they speak, with personalities usually based on the appearance of said fonts.
** The fact that you're only introduced to a fraction of the Royal Guards had to the creation of [=OCs=] that happens to be part of said royal guard, such as "Red," the star of a [[https://www.reddit.com/r/Undertale/comments/3x5uw2/hi_i_made_thorough_undertale_tribute_game/ certain fan game.]]
** Another trend is to make [=OCs=] based on the other humans Asgore killed, or humans with their own original virtues.
* The initial cast of ''VideoGame/KanColle'' featured girls who were [[AnthropomorphicPersonification the spirits of warships]] that were part of the Imperial Japanese Navy. Naturally, fan works tended to take advantage of this by adding shipgirls from other countries' naval forces, particularly [[UsefulNotes/WorldWarII the U.S. Navy]] (''FanFic/PacificWorldWarIIUsNavyShipgirls'' being one such). The game's gradually started adding its own foreign shipgirls, but even so, there's still a huge number of potential shipgirls available for fans.
* Oddly enough, ''VideoGame/MechWarrior 4 Mercenaries'' is predicated on this entire trope; the player takes on the role of Spectre, a [[DeadpanSnarker smart-assed]] mercenary captain, whose player-created independent unit is sponsored by (and effectively part of) one of the four most popular mercenary units in the Inner Sphere: the Kell Hounds, Wolf's Dragoons, the Gray Death Legion, and the Northwind Highlanders. Not only does this collectively make their company Sixth Rangers to these famous units, they also get to participate the Fed-Com Civil War and can even be involved in some of the more dramatic/climactic moments of the war.
* Alex only reads chapters from the ''Tome of VideoGame/EternalDarkness'' that her grandfather thought to hide away for her in preparation to fight Pious, and the book is still quite thick; given that the conflict has been going on for two millennia, involving people from any number of walks of life, it's quite easy to craft a chapter of your own, especially if you choose to [[AlternateHistory weave it into historical events]]. And since [[spoiler:Mantorok's goals upon his victory over all three Ancients are unknown, and there's at least one more Ancient out there]], the story can [[TheEndOrIsIt definitely progress]] [[DontCelebrateJustYet past Alex's time]].
* ''VideoGame/ToukenRanbu'' fans often do come up with their own fan designs for [[AnthropomorphicPersonification sword boys]] of swords that haven't been introduced yet, and there are even people who have made sword boy designs for famous European swords [[http://trouble-san.deviantart.com/art/Seiken-Ranbu-Excalibur-559061620 such as]] [[Myth/KingArthur Excalibur]] or fictional swords such as [[Anime/RurouniKenshin Kenshin Himura]]'s unnamed Sakabatou.
* ''VideoGame/{{Tattletail}}'' fan characters have become pretty popular. Given that the Tattletails are apparently a highly successful toyline that already comes in multiple colors, including some not encountered in the game, it's easy to justify coming up with new varieties and color schemes for them.
* It's remarkably easy to create your own ''VideoGame/{{Pikmin}}''. Just pick a color that hasn't been made official yet, give it some unique body feature no other Pikmin has, give it any power or immunity you want, and you're all set.
* The ''VideoGame/BendyAndTheInkMachine'' fandom has tons of cartoon {{Original Character}}s who are meant to be Bendy's co-stars. Often they are humanoid cartoons, {{Funny Animal}}s, or [[OurAngelsAreDifferent angels]] (the latter being HilariousInHindsight as Chapter 2 introduces Alice Angel). Seeing as the only rule is "make them look like a toon from the 20s/30s," it's easy to come up with your own character.
* ''VideoGame/AnimalCrossing'' [=OCs=] aren't too uncommon, though most fans prefer to work with the range of LoadsAndLoadsOfCharacters already given. Just make a brightly-colored FunnyAnimal and give them a quirky personality.
* ''VideoGame/EnsembleStars'' {{Original Character}}s tend to fall under two categories:
** A new producer, usually female. Oddly, even though the producer course and co-ed aren't supposed to open up until ''next'' year, they're usually in the year the game takes place in. Just pick which unit you want them to produce for and you're good to go.
** An idol or an entire unit that has not been seen yet. Makes sense -- at the time of writing, we've only seen about 30-40 Yumenosaki students and two Reimei students.
* ''VideoGame/{{Cuphead}}'' [=OCs=] mostly consist of nondescript humanoid characters whose head is a vessel that can contain liquid, like the two main characters. However, anything that would fit in a 30's cartoon is a viable OC, like ''VideoGame/BendyAndTheInkMachine''.
* ''VideoGame/{{Splatoon}}'' [=OCs=] mostly follow a basic pattern: A new inkling is in town, they start out messing around in the turf battles, then they do the events of Hero Mode and save the day. Falling in love with one of the Squid Sisters or Off The Hook (mainly Marina) members is optional, but it still happens a lot.
* ''VideoGame/ThemsFightinHerds'' makes it easy to come up with your own Key Seeker: just choose an ungulate species. You can even create entire ''tribes'' of [=OCs=] by picking a species that hasn't been represented yet (which includes mythical creatures) and giving them [[GangOfHats a defining trait]] based off AnimalStereotypes.
* ''VideoGame/YokaiWatch'':
** New yokai characters are easy to make. Just look up a {{youkai}} that hasn't been used, make it LighterAndSofter, and you have a new character. Heck, you don't even have to use a youkai. Supernatural and mythological creatures in general, no matter the country of origin, work.
** Original Yo-kai Watch owners appear in quite a few fan-works. Have an average Joe come across a mysterious watch, have them try it on, and suddenly they can see yokai.
* ''VideoGame/DetroitBecomeHuman'':
** Creating an original android model is fairly easy: pick 2 letters to begin, then a hundred number (100, 200, 300, etc.) to end. Give them a monochrome uniform, the triangle and armband, the LED, and an intended purpose, and that covers it. One could also just use a model that exists in-game--whether they look different than others of the same kind is up to the creator.
** Alternatively, it's common for original characters to serve in the DPD, as very few officers are seen or named.
* ''VideoGame/{{Fallout}}'':
** The RPG design of the series means it's very common to see the canon protagonist ([[VideoGame/Fallout1 the Vault Dweller]], [[VideoGame/Fallout3 the Lone Wanderer]], etc) as [=OCs=]. Another common fic premise is to have someone's protag from another game in the series visit a different game's setting (such as [[VideoGame/FalloutNewVegas Courier 6]] deciding to relocate to [[VideoGame/Fallout4 the Commonwealth]]).
** Excluding canon protagonists, [[VideoGame/FalloutNewVegas Couriers 1-3 and 5]] are ripe for the picking (Courier 6 is the protagonist, and Courier 4 can be found dead outside a shop in Primm).
** If one wants to make a vault dweller (or even design a new vault), there are at least 118 (excluding test or display vaults) in canon and we only know the purpose of around 32 of them. Just pick a geographic location unclaimed by a main series game (New York, New Orleans, the PNW, Texas, and the Midwest are all viable candidates), choose a plausible experiment that isn't too deadly or psychosis-causing, and you've got a vault!
* ''VideoGame/FTLFasterThanLight'' features several factions using [[SpecialEffectBranding spacecraft with characteristic aesthetics]], giving aspiring {{game mod}}ders something to base their own spaceship classes on.
* Making a ''VideoGame/ShovelKnight'' character is as simple as making a human[[AmbiguouslyHuman (oid)]] character, putting them in a face-concealing protective gear and naming them "<theme> Knight".
* ''VideoGame/{{Warframe}}'' saw new warframes being added [[PerpetualBeta over the years of its development]], so it should be no surprise fans keep making up their own warframes. Some of them (such as [[DragonKnight Chroma]]) actually ended up added to the game itself!
* ''Franchise/AssassinsCreed'' defines itself by exploring the memories of an entire family line using Animus technology, something that anyone can do as long as they have access to one. It's fairly easy to write a character on either side of the Assassin-Templar war with a lengthy -- and plot relevant -- family history, especially as, after ''VideoGame/AssassinsCreedII'', both sides have their own Animus platforms. In fact, in the multiplayer for ''VideoGame/AssassinsCreedBrotherhood'' through ''[[VideoGame/AssassinsCreedIVBlackFlag Black Flag]]'', the players are explicitly modern-era Templar initiates learning real-world assassination skills from the Bleeding Effect, the same way that series protagonist Desmond did.
** As the series is meant to take place in the real world, and primarily features two covert organizations with plentiful numbers of operatives from all walks of life, a writer could easily use ''their own ancestors'' as a [[RealPersonFic real life]] OCStandIn during the respective historical era they lived in.
* ''VideoGame/MarySkelterNightmares'':
** Even though it being forgotten makes OC Blood Maidens pretty unlikely, it's actually quite easy to make one. They're all based on characters from fairytales. It's not just Brothers Grimm fairytales either thanks to Kaguya (based on ''The Tale of the Bamboo Cutter''), and they aren't limited by being female either, as Hameln is based on the male titular character of ''Literature/ThePiedPiperOfHamelin''. The only thing that's difficult is using a character from an already used fable, as Red Riding Hood's Blood Skelter references the Big Bad Wolf and Alice's bow in both Massacre AND Blood Skelter looks like rabbit ears (possibly like the White Rabbit). We also already know that others before the game existed, so just make them one of those... though that would mean they died before the game's events.
*** That is no longer an issue due to ''[[GrandFinale Mary Skelter Finale]]'', which introduces Charlotte and Mary, 2 Blood Maidens that were always at Dawn... but somehow managed to escape being noticed by Professor Tohjima.
** Blood Youths like Jack are also possible, and the limitations are the same minus Blood Skelter extra references, but there's also how Jack is the ONLY Blood Youth in the entire franchise.
*** Once again, ''Finale'' makes that a non-issue by introducing Juu.
** There are multiple Jails too, as teased in the original and used in the sequel, so it would also be possible to make other Blood Teams. Whether they're an ''2''-style FamilyOfChoice or another group that was brought together by some follower of Snark is all the writer's decision to make.
** ''Mary Skelter Finale'' also introduces a new faction of Blood Maidens known as Genocide Pink. Just give them an ''2''-style white-on-black outfit, use blue instead of the Blood Team's pink, and change the FairyTale name to one themed after a CruelAndUnusualDeath, and voila! New member! ...though once again, you may need to kill them off before the events of the game.
* ''VideoGame/CodeVein'''s character creator makes it easy to design your own OC. Each character has their own unique Blood Code that gives them special powers ([[spoiler:even the player character, who has the unique power to [[PowerCopying copy other Revenants' Blood Codes]], later gets a Blood Code, Queenslayer, that is specifically theirs]]), so it's easy to make up your own by choosing one or more weapon types the Code is specialized in, what types of Gifts it has, and naming it after either an RPG class or a deity that isn't already covered by the canon Blood Codes.
* ''VideoGame/TransformersWarForCybertron'' and ''VideoGame/TransformersFallOfCybertron'' have this in their multiplayer modes, where players are encouraged to assemble their own character from a variety of premade parts within a given class (so tank parts for warriors, car parts for scouts, etc) and go into large-scale battles with this new Transformer. As a lot of existing character model parts from the single-player campaign were reused, you ''could'' assemble an existing character such as Optimus Prime or Megatron and go into battle using their look and color scheme, but High Moon Studios understood that fans of this franchise would want to make their own characters and therefore made it an option in their games.
* ''VideoGame/TwistedWonderland'': The blank slate nature of the player character makes it ridiculously easy to put one's OC in their place. It's also easy to make some new students at either Night Raven College or another school (like the never-seen Royal Sword Academy): just take a Disney villain or an item associated with them and turn them into a {{bishonen}} with a fancy name.
* ''Soul Edge'', the first entry of the ''VideoGame/SoulSeries'' introduced series mainstay Sophitia Alexandra, one of [[TheChosenMany 24 holy warriors]] tasked with destroying the titular EvilWeapon by [[Myth/ClassicalMythology Hephaestus]]. Only one other holy warrior has been seen since, with the following game, ''Soulcalibur'', bringing in Aeon Calcos aka [[WasOnceAMan Lizardman]]. [[note]]Who was presumably the 14th holy warrior sent out by the Greek god of the forge, given that the divine weapon given to him is called the Xi Sword. Comparatively, Sophitia possesses the Ω Sword, suggesting she was the 24th and last of these warriors.[[/note]] This leaves a whopping 22 characters unaccounted for, though few fans have ever touched upon the subject--possibly because of Aeon's pitiable fate and the fact that Sophitia mostly succeeds in her mission during her first journey, either making the remaining holy warriors DoomedByCanon or rendering their quests [[AllForNothing pointless]]. Then along came ''VideoGame/SoulcaliburV'', where it's revealed (via [[AllThereInTheManual supplemental materials]]) that Hephaestus has sent out another group of holy warriors, whose objectives are destroying Soul Edge (again) and slaying a certain Lizardman himself on account on Aeon being bestowed with CannibalismSuperpower by Ares (who Hephaestus most certainly does ''not'' want to obtain Soul Edge). The identity of these new holy warriors? The custom characters who face Aeon in a Destined Battle during Arcade Mode.
* ''VideoGame/GalaxyAngel'' is rife with possibilities, as four of the six universes with intact civilizations have their gatekeepers as their only known residents. Angels, ships, Emblem Frames, villains, planets; you name it, you can create it.
** It's not even limited to the four unexplored universes, as Fanfic/KhaosOmega and another author (who actually ''inspired'' Khaos in the first place) have both implemented new Emblem Frames that a male crewmember unexpectedly finds himself compatible with (and both even end up romantically involved with one of their team's female Angels - Khaos did it in NEUE (the second trilogy's main universe) and the other author did it in EDEN).
* ''VideoGame/{{Bugsnax}}'' [=OCs=] come in two flavors; the Grumpuses and the Bugsnax themselves. Making a Grumpus OC is as simple as picking a fur color, a couple of identifying features like hair or accessories, and a few nonsese words for a name. As for Bugsnax, there are plenty of foods available to be made into faux-insects.

[[folder:Visual Novels]]
* This isn't too hard for the ''Franchise/AceAttorney'' series. You just need to think of a PunnyName for your new lawyer/police detective/murder victim/suspect/etc and give them a few personality quirks. Also, ''[[VisualNovel/PhoenixWrightAceAttorneyDualDestinies Dual Destinies]]'' asserts the trend name for lawyers of the Wright Anything Agency: Myth-inspired first name, legal term-inspired surname, a suit color, and if you're going the extra mile, a weird hair shape. For everyone else, a visual motif doesn't hurt. Fan-works also ''love'' creating new past unsolved cases, following the canon naming scheme of "Letter Letter-Number Incident." This fits very well seeing as canon keeps adding more of these with each game.
* In ''Franchise/{{Danganronpa}}'' it's incredibly easy to make a new Ultimate Student: all you have to do is give them a talent that hasn’t appeared in the series yet (though duplicates sometimes exist in canon), a [[AnimeHair weird hairstyle]], and a couple of personality quirks. There's already [[https://www.deviantart.com/star-driver567/art/Dangan-Ronpa-ID-Card-Template-440756735 a template in the franchise]] for information on each student, making fan-made characters even easier to describe. Since the only recurring element from each entry in the franchise is the presence of [[BigBad Monokuma]] [[spoiler:and Junko Enoshima]], entire killing games can be made from a cast of [=OCs=]. So many of these types of stories have been made that [[FanNickname the fandom even has a name for them]]- Fanganronpa.
** Since the Ultimate students attend Hope's Peak Academy and only a handful of classes have been shown in canon, fanfic authors can create classes full of original characters forced to murder each other by Monokuma.
** Ultimate talents don't even have to be all-encompassing: [[Characters/DanganronpaV3FemaleStudents Kaede Akamatsu]] is the Ultimate Pianist even though [[Characters/Danganronpa2FemaleStudents Ibuki Miuda]] is the Ultimate Musician, since Ibuki focuses mainly on rock music. So for example, if you want your original character to be the Ultimate Dancer even though [[Characters/Danganronpa2FemaleStudents Hiyoko Saioniji]] is already the Ultimate Traditional Dancer, it's allowed if you make your OC's talent be based around modern dancing instead.
** Some Fanganronpas have a new mascot instead of Monokuma, such as a bird or monkey version. Canon supports this, as long as the mascot has their name start with "Mono."
** If you want to make your OC a child instead of a teenager, they exist in canon too! The naming scheme is "Lil' Ultimate" and then whatever class they're talented in.
** On the other side of the scale, "Ex-Ultimate" students are also common for creating college-aged or adult alumni of the academy.
* In ''VisualNovel/FateStayNight'' by [[Franchise/{{Nasuverse}} Type Moon]]:
** The First and Second Grail Wars have been COMPLETELY blank for Masters and Servants, as well as only 2 Servants named and 2 more mentioned for the Third Grail War with 0 Masters. Some fan stories have filled in their events, commonly stuffing the first one with purely Japanese spirits. Some even add in new classes based on a few throwaway lines.
** There have been [[Literature/FateStrangeFake Grail]] [[LightNovel/FateApocrypha Wa]][[VideoGame/FateExtra rs]] outside of the Fuyuki one, meaning one can set a story in an all-new Grail War. Creating a Servant is quite simple: find a legendary figure and make Noble Phantasms based off the most notable artifacts and events in said legend's life. For example, ''LightNovel/FateApocrypha'' does this with two sets of 7 masters with 7 servants '''and''' a member of a new servant class called Ruler whose function is that of a referee and judge. ''Apocrypha'' furthermore has ''Variant'' [[CrypticBackgroundReference Holy Grail Wars taking place all over the world]], which any mage can participate in any time with references to a "golden age of Hassans" when Masters directly targeted each other, conflicts in Greece stalling out due to the scramble to get the best heroes first, and even an InUniverse [[TheWikiRule wiki]] to consult!
** Hell, they don't even need to be legendary figures. Some people have used UsefulNotes/SimoHayha as an Assassin, or Creator/AudieMurphy as a Berserker. While these two are very notable people, they're not "legendary" in the manner of King Arthur or Cú Chulainn, and thus, [[FlameWar debates]] over whether they ''should'' be Servants tend to flare up, ''especially'' if they bring up the WordOfGod regarding whether Servants can be based off people from the 20th century on (the issue [[https://www.reddit.com/r/grandorder/comments/88yqgs/translation_of_roundtable_talk_kinoko_nasu_fate/ as far as Nasu is concerned]] being that contemporary figures are extensively documented, where he likes making liberal interpretations of comparatively brief information).[[note]]Most Servants born after 1900 so far have been original to the Nasuverse... aside from Anastasia in ''Fate/Grand Order'' and [[spoiler:Voyager in ''Fate/Requiem'']].[[/note]]
** Got a particularly weird Servant idea? Not a problem. Even across the official Franchise/{{Fate series}}, the Servant roster has included [[BeethovenWasAnAlienSpy legendary figures who had much stranger lives than history recorded, or proved to be much stranger beings than believed]], legendary figures who've undergone surprising post-mortem transformations, versions of legendary figures from {{alternate timeline}}s, {{anthropomorphic personification}}s, fictional characters who turn out to have been real, and characters who even in this 'verse are supposed to be fictional.
** And as ''VideoGame/FateGrandOrder'' demonstrates, you don't even need to have a Grail War, or stick to its limits on Servants, as it features a single Master calling on hundreds of Servants to assist them in saving humanity, including the various Extra classes from across the Fate series -- Avenger from ''VisualNovel/FateHollowAtaraxia'', Ruler from ''LightNovel/FateApocrypha'', Moon Cancer and Alter Ego from the ''VideoGame/FateExtra'' series, and Foreigner, an ''FGO''-original class.
** Thanks to ''LightNovel/FateApocrypha'''s introduction of Pseudo-Servants (and further expansion from ''Grand Order'' and ''Lord El-Melloi II Case Files'', such as naming the idea and adding the related Demi-Servants), even established canon characters in the Fateverse have no excuse not to become Servants one way or another. As long as a connection between the legendary figure and their host character can be made, the sky's the limit.
* ''VisualNovel/{{Tsukihime}}'' has a sort of most-wanted list of bad guys, the 27 Ancestors of the Dead Apostles. Several of these are still unrevealed, making it easy to introduce a new villain as one of them.
* A ''VisualNovel/HatofulBoyfriend'' OC is easy to create, as the series takes place at a school. Adding a new character who attends St Pigeonation's is as easy as getting a stock photo of a bird and designing a human form for them (along with whatever ridiculous and/or tragic backstory the author feels they require). Members of the Hawk or Dove Parties aren't quite as common but still feasible.
[[/folder]]

[[folder:Web Animation]]
* ''Machinima/RedVsBlue'': There's fifty Freelancers (one for every American state -- and less than half were revealed [[note]]12 during the first ten seasons; and that's before Season 14 introduced "The Triplets", and 15 had nine dead ones in a WaxMuseumMorgue[[/note]]) and potentially a whole Greek alphabet's worth of AIs, so new Freelancers and AIs are ''extremely'' common.
* ''WebAnimation/{{RWBY}}''. Creator/MontyOum came up with [[https://twitter.com/montyoum/status/406894139746172928 rules on how to name original characters:]]
** The ExtranormalInstitute setting and color-coded characters open a lot of room for Sailor Earths. Just pick a color, give the character an outrageous (and often impractical) looking outfit, an equally outrageous and complex weapon, a Semblance (a special power unique to the character) and you're done. For the furries out there, you can also make your character a Faunus by adding one and ''only'' one animal part to your character[[note]]so you can't have both [[LittleBitBeastly animal ears and a tail]], although some people just ignore that rule[[/note]], which may or may not come with additional powers such as SuperSenses, WolverineClaws, {{flight}}, or [[BewareMyStingerTail venom]].
** The FunWithAcronyms team naming the ExtranormalInstitute practices is used to create entire four-person teams of characters as well and they don't even have to spell out the team name in question (e.g. the title itself.)
* ''WebAnimation/BattleForDreamIsland'' {{Original Character}}s, known more generally as object show [=OCs=], are rather simple to create: choose an object, and... that's it. Optionally add an "-y" to the end of the object's name.
* ''WebAnimation/HazbinHotel'' [=OCs=] are ridiculously common. Just create a humanoid character, give them a reason to be in Hell and have them land at the hotel for whatever reason.
[[/folder]]

[[folder:Web Comics]]
* As one might guess from the title, the ''Webcomic/SailorSun'' webcomic makes full use of this trope even though it should not be confused with the trope itself.
* ''[[http://www.sailorranko.com/ Sailor Ranko]]'', another webcomic based on ''Franchise/SailorMoon'' fanfiction, in this case a well-known FukuFic series that uses the Sailor Earth trope to shoehorn ''Manga/RanmaOneHalf'' characters into ''Sailor Moon''.
* Prematurely shot dead by ''Webcomic/{{Periodus}}'', after the creator claimed that now someone could make a fic about Oxygen, and a commenter threw out a several-sentence parody.
* ''Webcomic/{{Homestuck}}'':
** The webcomic revolves around sessions of a special computer game called Sburb. It's not uncommon for fans to invent their own characters who order and receive the beta in the mail, particularly on the Forum Adventures section of the forums.
** It's implied that the four canonical kids are the only ones left, given that there seem not to be more "exiles" and the kids' meteors are by far the biggest ones (presumably marking them for the only session that actually gets in). It's implied that nobody else who actually received the game actually got into the medium because they [[PlotInducedStupidity couldn't figure out how to get into the Medium]], which is portrayed in canon as a fairly simple process. [[MisaimedFandom This of course is totally ignored by fan-adventure writers.]]
** It's only [[http://www.mspaintadventures.com/?s=6&p=002776 Dave and Jade's meteors]] that dwarf all the others; [[http://www.mspaintadventures.com/?s=6&p=002774 Rose's twin meteors]] are pretty average-sized, and John's isn't given the same examination but is probably even smaller. The kids' Sburb session breaks a lot of the rules anyways, so having unusually gigantic meteors for half its players could be part of that anomaly. Also, given that they have the ''entire planet Earth'' to be exiles in, it's not that implausible that the groups of exiles corresponding to the main and the Sailor Earth sessions just haven't crossed paths. (Given how much predestination figures in the plot, it could be quite reasonably {{Hand Wave}}d as the exiles for each session being drawn to each other and only each other.)
** There's no excuse, however, for the multitude of fan troll sessions -- the twelve canon trolls are explicitly the only ones who will ever play Sburb (or rather Sgrub) because their version was coded by a few of their own players, not released by a company like on Earth. The most canon-friendly fan sessions are the ones that invent entirely new species for the players to be, which are in themselves an example of this trope given how similar they tend to be to the trolls -- most fan-created species have their own romance system, calendar, family structure, and equivalent of bedding [[FollowTheLeader because the trolls were different in these fields]].
** [[BadassBystander fedoraFreak]]. Text messages on Dad's phone reveal that one of his acquaintances (actually their neighbor) actually entered and survived in another instance of the Medium and presumably reached God Tier, since the last correspondence with him has him dying on a Quest Bed. That certainly provides a whole load of precedent.
** Such a plot was actually used as an AlternateRealityGame-like [[http://members.shaw.ca/aknowlan/forapocalypse2.html explanation]] for upgrading the fandom's [[strike:forums]] [[InsistentTerminology fora]] software.
** A popular subset is making a {{Crossover}} - characters from another work play Sburb while chatting between each other. Sometimes, the author deliberately doesn't reveal what is the crossed-over verse, challenging the reader to guess what it is from the characters' [[OnlineAlias chumhandles]] and conversations.
** Related to this trope, the author [[http://mspandrew.tumblr.com/post/12680094125/answers has joked]] that every fan troll is canon. Even the bad ones.
** Though it overlaps with EpilepticTrees, the hypothetical [[http://www.mspaintadventures.com/?s=6&p=006044 (well, formerly hypothetical)]] thirteenth Troll falls into this. Note that the actual thirteenth troll turned out to be an in-universe [[AscendedFanboy Ascended Fangirl]], and is practically an avatar for ''Homestuck'' fandom. In other words...[[StealthPun a fan troll]]. And then she turned out not be a troll, but a new species ... which has its own romance system, family structure and equivalent of bedding. No word on the calendar yet.
** One of the "God-Tier" rewards for the Homestuck adventure game kickstarter was pledging ''ten thousand dollars'' to the game, in order for the person's fantroll to make a cameo appearance (note that the person would have to pay a ''hundred'' thousand for their fantroll to survive beyond the first panel) in-story, which only two people paid for. This, along with the way time and space works in Homestuck essentially have given a proper justification for fantroll or OC kids sessions (they could be thought of as existing within their own universes and timelines, such as the one described in the flashback with the aforementioned cameos).
* A webcomic known as ''Bishoujo Senshi Sailor Earth'' exists, using an already existing character (Naru) as Sailor Earth. However, she was not a part of the original Sailor Senshi team/group of friends and is added based on an answer the creator gave to fans about using Naru as Sailor Earth should she ever be needed.
* Because ''Webcomic/{{Drowtales}}'' has an on-site RP section this is very common, though there are [[http://forums.drowtales.com/viewtopic.php?f=82&t=12195#p494389 very]] [[http://forums.drowtales.com/viewtopic.php?f=82&t=12195#p494391 specific rules]] about how created characters can be related to canon characters, and a few characters have actually shown up [[AscendedFanfic in the main story as cameos]].
* The sadly-unfinished ''Webcomic/ZeldaComic'' introduced a new, GreaterScopeVillain who was a fallen Sage named Kasuto, in honor of the only town in ''VideoGame/ZeldaIITheAdventureOfLink'' that didn't have a name already attached to a Sage.
[[/folder]]

[[folder:Web Original]]
* Many fans of WebVideo/{{Jreg}} have created new characters based on RealLife or fictitious ideologies not depicted in his videos.
[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/AdventureTime'' has a large cast of [Noun] [Royalty]s, especially [[GratuitousPrincess princesses]], so it's not that hard to invent a new one. Oddly, the most popular kind of OC seems to be an Ice Prince(ss), who is generally either the child or niece/nephew of [[AnIcePerson the Ice King]] (which makes little sense given what we know about him in canon). Long-lost relatives of [[EmperorScientist Princess Bubblegum]] and other humans (sometimes serving as love interests for Finn to fill the void left following his break-up with Flame Princess) are also fairly common.
* ''WesternAnimation/AvatarTheLastAirbender'':
** The cartoon finishes on something of a cliffer. Though this was expanded upon later in the SequelSeries ''WesternAnimation/TheLegendOfKorra'', there are many fics that attempt to write a ''Book 4: Air'' (which would make sense, considering how much the show focused on the four elements).
** There are tales about a ''previous'' Avatar: Pretty easy to do, since we don't know how may Avatars there have been and we only know the names of nine of them: Aang, Korra, the five Avatars immediately preceding Aang (Roku, Kyoshi, Kuruk, Yangchen, and Szeto), Salai (a historical Avatar mentioned in passing in ''Literature/TheRiseOfKyoshi'') and the first Avatar, Wan.
** Another variation is a story about the complete learning cycle of a later Avatar, anywhere from directly after Aang or Korra to an Avatar in a modernized setting. Very rarely it inverts the concepts and has an Avatar living in a futuristic space age.
* The same setup as ''Anime/OjamajoDoremi'' goes for ''WesternAnimation/TheBackyardigans'', but it's for the purpose of increasing the cast. Also, the Backyardigans have the same theme colors as the five main Ojamajos.
* Want to create an original character for ''WesternAnimation/BuzzLightyearOfStarCommand''? All you have to do is decide if you want them to be human or alien and whether or not you want them to be a Space Ranger. Simple.
* ''WesternAnimation/CaptainPlanet'' -- only five of the continents (Africa, North America, South America, Europe and Asia) are represented in canon, so it's not hard to create Planeteers who come from Australia, Oceania, maybe even Antarctica, Central America and Western Europe, as Linka represents Eastern Europe. Just give them a new element, and there you go.
* ''WesternAnimation/ChipNDaleRescueRangers'' fanfics often feature {{Original Character}}s who just happen to also be crime-fighting rodent vigilantes who end up teaming up with the Rangers to solve some big case, normally joining the team in the process. Less common are rival crime-fighting groups, though these do pop up occasionally (more often in official comic spinoffs than in fanfics). It seems to be the goal of many fanfic writers to eventually add more and more characters to the Rangers, to the point that, for every nonvillainous character on the show (and some villainous ones), there is probably a fanfic somewhere where they join the team (Foxglove, Tammy, and occasionally Sparky are the most common targets of this). Add to this all the AuthorAvatar characters who have joined the team, and the roster probably numbers in the dozens, if not hundreds.
* All characters in ''WesternAnimation/{{Chowder}}'' are named after food, so Chowder {{Original Character}}s tend to follow this pattern.
* Shoehorning new Lyoko Warriors into the group in ''WesternAnimation/CodeLyoko'' fic is all too common, as they are in a whole school full of potential new warriors, and they have endless need for new help.
* It's not hard to have [=OCs=] for ''WesternAnimation/CodenameKidsNextDoor''. Just pick a number. Or become a member of the Safety Patrol. Or be delightfullized. Be CrazyAwesome as a child or teenage character. Make some sort of villain (just come up with a concept you dreaded as a kid).
* ''WesternAnimation/Foot2Rue'' -- we never see Tag's mom, Eloise's male relatives, Samira's brothers and sisters, Lil Dragon's dad or Jeremy's younger half siblings, so there's plenty of OC potential there.
* ''WesternAnimation/FostersHomeForImaginaryFriends'' FanFic tend to introduce new imaginary Friends moving into the home. And move into the same room as Bloo despite him already having three roommates. It's even worse when the author decides, for some weird reason, that Bloo should fall in love with this Sailor Earth character. Bloo has never ever shown any affection for female creatures, except for Frankie. That was once, when he saw her in a dress for the first time, and his affection was limited to chanting "She's hot!"
* ''WesternAnimation/InvaderZim'' is prone to acquiring new Invaders. Or Tallest, if you're feeling ambitious. The creator explicitly mentioned this on the DVDCommentary, saying he would enjoy going to the homes of the little kids who believe they're "Invader Tom" or "Invader Sally" and wrecking their dreams by noting they weren't at the Great Assigning (every Invader, even those that didn't appear, are accounted for). Note that these new Invaders, or any other Irken [=OCs=], almost inevitably wind up going to Earth and ending up in Ms. Bitters' class. Which seems awfully familiar to anyone who watched the "Tak" episode. Also, an alarmingly high portion of these new Irkens have blue eyes -- which is explicitly stated to be impossible in-universe.
* The [[LoadsAndLoadsOfCharacters sheer amount of characters]] in the later seasons of ''WesternAnimation/JusticeLeague Unlimited'' make it easy for anyone and everyone to enter their [[OriginalCharacter OC]] into the League with absolutely no disruption of canon at all.
* To create a [[GangOfHats Mute group]] for ''WesternAnimation/KipoAndTheAgeOfWonderbeasts'', just pick an animal species to [[FunnyAnimal anthropomorphize]] and give them some sort of theme and an associated style of music.
* Considering the masses of characters in the ''WesternAnimation/LegionOfSuperheroes'', slipping in a hitherto-unseen OC who recently got transferred to the main team (aka, the relevant team) is easily done. Alternatively, you could just add a character who only appeared in the comics.
* With Stitch from ''WesternAnimation/LiloAndStitch'' being Experiment 626, fans had approximately 625 remaining experiments to come up with for themselves. However, ''[[WesternAnimation/LiloAndStitchTheSeries The Series]]'' (as well as some tie-in comics published in ''Magazine/DisneyAdventures'' and the ''Anime/{{Stitch}}'' anime made some time later) showed some of these experiments and ''The Series''[='=] [[WesternAnimation/LeroyAndStitch finale movie]] listed [[Characters/LiloAndStitchExperiments all 625 of the other experiments]] made prior to Stitch in the credits. All that has done was make giving your fan-made experiment a name and number unnecessary now. Even then, fans often tend to ignore the admittedly bland or ridiculous names for the unseen experiments in favor of just going with whatever they want for their "experiment-sonas"/"Stitch-sonas".
* ''WesternAnimation/TheLoudHouse'': A number of {{Original Character}}s are more siblings, cousins, or [[FanCreatedOffspring children]] of the pre-existing Louds that are shoehorned into the already full household. Naturally they have names starting with the letter "L".
* ''WesternAnimation/MiraculousLadybug'':
** Writers are often ''required'' by the plot to create {{Original Character}}s to be akumatized. Unusually, this functions to keep the story more focused on Ladybug and Chat Noir, as akumatizing any existing characters would require more narrative focus than just having a random person show up for a plot-mandated fight.
** The Miraculous holders. Fanartists tend to either invent brand new miraculouses and Kwamis, based on varied animals, and their holders; or to represent the people who could have the non-used jewels seen in the credits: the fox, the peacock, the bee, and the turtle. [[spoiler: Or at least non-used in season one. Since then, it's been revealed that the turtle, the fox, the bee, and the peacock holders are respectively Master Fu and Nino, Alya, Chloe, and Mayura.]] The episode "Sapotis" also reveals the existence of an additional ''dozen'' Miraculous beyond the main seven, corresponding to the animals of the EasternZodiac. [[spoiler:And then the episode "Feast" revealed that there are more miraculous boxes than the one that contains the nineteen known ones, and it's implied there's a lion miraculous among them.]]
** The American special reveals that there is a Miraculous set based on Native American culture, with Jess gaining the Eagle Miraculous, and WordOfGod revealing the identites of the others. It's not too hard for a fanfiction writer to come up with holders for those Miracuoluses.
* ''WesternAnimation/{{Mixels}}'' has a lot of fan-created tribes based on different themes and elements. Most of the time, they contain female members. Interestingly, for this series LEGO actually ''encourages'' the fans to create their own works with the Mixel sets, thanks to their FusionDance gimmick.
* It's pretty easy to create a fan-character for ''WesternAnimation/{{Trollz}}'', due to the RockThemeNaming. Emerald is a particularly popular choice, as green isn't on the color spectrum the girls have.
* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'':
** The series has inspired fanfics not only about the "Seventh Element of Harmony", but {{Evil Counterpart}}s to the Elements (Generosity vs. Selfishness/Greed/Avarice, Laughter vs. Despair, etc.), usually known collectively as the Elements of Discord. Note a bogus Season 2 episode list that got widely circulated and believed included an episode about the Seventh Element of Harmony.
** Trixie making a HeelFaceTurn and becoming the Seventh Element is quite common.
** In a bit of irony, canon would eventually have Sunset Shimmer add a seventh color to the rainbow generated by the Elements when defeating the Dazzlings, which naturally added fuel to the fire. It's since been explained that hers is Empathy, and that it's not officially one of the Elements.
** Fan favorite Derpy Hooves is often depicted as hanging out with and interacting with the Mane Six. Her fanon-established daughter Dinky is similarly often included with the Cutie Mark Crusaders (despite having been repeatedly depicted with a cutie mark, although it keeps changing).
** Besides, as it is a world inhabited by what's deemed to be MANY Ponies, one simply needs a name and a cutie mark... you would not be hard pressed to find a brony with a Pony OC.
** To a much lesser extent, the idea of other "[[CelestialBody Astral Beasts]]", which was started off with the Ursa Major and Ursa Minor, and quite obviously based on other [[StellarName constellations]].
** There's also a common trend for fans with Pegasus [=OCs=] to make them members of the Wonderbolts. In the show itself, there's about 12-15 members of the main team, with Spitfire and Soarin' being the most prominent and a few others like Fleetfoot and Misty Fly also having recurring appearances. That doesn't even take into account how many members of the reserves and cadets-in-training there are.
* ''WesternAnimation/OKKOLetsBeHeroes'': Since the world is full of [[FantasyKitchenSink fantastical people]], such as [[OurMermaidsAreDifferent mermaids]], [[OurGhostsAreDifferent ghosts]], [[OurWerewolvesAreDifferent werewolves]], etc., and chock full of villains and heroes, it's quite easy to make your own character. The creators of this show even [[https://ok-ko.tumblr.com/post/161861408154/official-pow-card-template-for-your-ok-ko-oc-one made an official template for OCs.]]
* Since there are only three official ''[[WesternAnimation/ThePowerpuffGirls Powerpuff Girls]]'' around, in came a rainstorm of PPG [[OriginalCharacter OC]]s, mostly being Powerpuffs for any other color besides pink, blue and green. When it's not the rest of the rainbow, it's just a new-and-improved Bunny brought BackFromTheDead and beautified, or sometimes it's the introduction of new Rowdyruff Boys (usually in stories where the original ones had a HeelFaceTurn). One of the most well-known Powerpuff Sailor Earths around is Bell, the white Powerpuff from the ''Webcomic/PowerpuffGirlsDoujinshi'' by Bleedman. Even then, she's an antagonist.
* ''WesternAnimation/{{Recess}}'' always has the possibility for "The New Kid", or any other of the nameless kids (or their nicknames) present on the playground. It wouldn't be that hard for something like "The Slide Climbing kid" or "The Video Game Kid".
* Many ''WesternAnimation/RoadRovers'' fans loved creating their own, by simply picking a breed, gender, nationality, and maybe superpower.
* There are an insane amount of ''WesternAnimation/SouthPark'' fanfics that involve a new kid (usually female) moving to town and becoming friends with the four main boys. If the character is a girl, as is the case with 99% of these stories, a romantic relationship is guaranteed, with Kyle being the most popular boy to pair her with.
** Interestingly, the official video game ''VideoGame/SouthParkTheStickOfTruth'' opens with this plot (minus any romance).
* ''WesternAnimation/StevenUniverse'', which involves a race of [[NinjaPirateZombieRobot magical alien]] [[SiliconBasedLife crystal people]] called Gems, quickly gave rise to "gemsonas"--pick a kind of gem or stone for the name and design a character, given them a personalized weapon (scythes are famous for this), and you're good to go. Naturally, this only became more popular after the middle of season one, when new Gems began to appear on the show itself. While canonically the Gems are [[OneGenderRace all female]] (excepting the title character, who's a HalfHumanHybrid), gemsonas match a fan's preference. The problem arises however, when one considers the limited amount of crystals/minerals out there. While there's a few hundred regular gemstones, and a few hundred more uncommon, though readily pronounceable ones to pick from, there's a good 2000 or so unlikely to be used[[note]]It helps that the show itself bounces between introducing popular gems like aquamarine and more obscure ones like carnelian[[/note]]. Not too many would settle for a Gemsona named Akhtenskite, for instance. Thus, the inevitable OneSteveLimit (pun not intended) is bound to crop up. Lampshaded in a fan animation [[https://www.youtube.com/watch?v=KJbkylxnTsw here]].
** However, the show itself has multiple characters with the same gems -- there's been multiple Rubies and Pearls shown, for example. They're not all main characters, obviously, but this is one case where you could have more than one character based off the same thing and still have it fit into canon.
** Since FusionDance is also a big part of the series, it's not uncommon for people to create multiple gemsonas ''and'' fusions of their characters. Making up fusions for combinations of the main characters that haven't been seen yet is another favored topic.
* Another fandom that makes this easy is the ''WesternAnimation/StormHawks'' fandom. All you need is to either pick a pre-existing species (Merbs are the most common in fanfiction) and pick the name of a bird. Most of these also tend to be a love interest for Stork, of all people...
* Every version of ''WesternAnimation/StrawberryShortcake'' also allows the creation of infinite Sailor Earths. The characters are named for food. Limitless, eh?
* ''WesternAnimation/TeenTitans'' fandom contains PLENTY of fics where a new girl or boy (far more rare) shows up in Jump City with powers and joins up as the [[SixthRanger sixth Titan]].
** Plenty of these new Titans seem to indeed be Terra clones, in that they're either working for or related directly to Slade. OriginalCharacter apprentices were a dime a dozen for quite a while.
** The series ends on a very open-ended note, leaving that opportunity wide to the masses to make something of the sort.
** Another popular route to take when creating Teen Titans [=OCs=] is to make a Titans North or Titans South (or a Titans Whatever-country-or-continent-suits-the-story's-purposes), using Titans East as both justification and inspiration. This way, an entire team of new characters can be made without interfering with canon too much. Yet another option is to add a [[SixthRanger sixth Titan]] to Titans East (some might not even consider them a "sixth" member, claiming that Mas and Menos count as one Titan) to pair them off with Speedy or Aqualad. And of course, it's perfectly reasonable and very popular to simply create new [=OCs=] that are Honorary Titans, residing wherever they want and tied down only to a duo at most. And that's just when it comes to creating heroes. Villains and neutral characters are popular among creators too; after all, what fun is a new hero without a new archenemy to wipe the floor with? So in all honesty, Teen Titans is among the easiest fandoms to create characters for, no matter how the creator decides to pull it off.
* The abundance of British locomotive types has made making original characters for ''WesternAnimation/ThomasTheTankEngine'' extremely easy. Road vehicles, boats, planes, humans, even non-British locomotives are also no-brainers, to the point that foreign locomotives like Hank, Bash, Dash and Ferdinand (USA), Flora (Ireland), Hiro (Japan), and Millie (France) are canon.
* Comes up from time to time in ''WesternAnimation/ThunderCats'' fanfiction, both for the OS and the [[WesternAnimation/ThunderCats2011 reboot]]. There are many cat species not used in the show for writers to choose from. Add in how the reboot expanded on the species of the other animal races, and there are even more possibilities.
* The ''WesternAnimation/TotalDrama'' series, by virtue of having its contestants based on teen and elimination game stereotypes, is particularly suited to such knockoffs:
** Remakes of the first season often have one or two new characters join the canon cast. If there is only one, it will usually be an AuthorAvatar.
** Stories set in new seasons tend to use ostensibly original characters that have [[SuspiciouslySimilarSubstitute remarkably similar characteristics]] to the canon cast. This is easily--sometimes explicitly--justified with the conceit that the in-universe producers are screening for certain types, and [[Administrivia/TropesAreTools has the benefit]] of freeing the writer from having to acknowledge canon relationships, for example.
** More audacious fics such as ''[[Fanfic/TotalDramaComebackSeries Total Drama Battlegrounds]]'' may introduce a whole new cast of stereotypes while keeping the original cast as well.
* ''Franchise/{{Transformers}}'' makes this even easier, even if you don't take a [[MerchandiseDriven toy that never got to the screen]] or one of the base characters not already in that reboot, and characterise it for yourself. Pick a cool alt for your OriginalCharacter (thanks to Hasbro, even Triple Changers are allowed now) and a name that fits the "CodeName as real name" motif (there's freaking name generators out there), and you're [[StealthPun ready to roll out]]. You don't even need to say ''why'' they're there, because they're there for the same reason everyone else is there -- there's a war, dammit! This is okay because Hasbro uses the same method for inventing their own toy-only characters -- and their not-toy-only characters -- and the writers of the various cartoons, comics, and other fiction use it for their [[ToylessToylineCharacter non-toy characters]]. It's one of the few fandoms where the "Sailor Earth" approach is not only acceptable, but accepted as standard operating procedure.
** ''WesternAnimation/BeastWars'' has the question of the unrecovered stasis pods, which leads to the uniquely FandomSpecificPlot of Beast Warriors continuing the fight on other continents (to explain characters with non-African beast modes), or long after the show ended (some of the comics operated on this concept).
** ''Anime/TransformersCybertron'' has the various themed Planets with their Cyber Keys as a core concept. Some fans have taken to creating their own Planets with various potential factions and alternate modes represented--popular ones include 'sky worlds,' typically a WorldInTheSky that favors aerial alternate modes, and 'water worlds' for aquatic modes.
* ''WesternAnimation/{{Tugs}}'' revolves around two fleets of tugs. To introduce a new character, all that's needed is for one of the fleet's captains to suggest that they need another tug because there's too much work, or (in the case of the Z-Stacks) to make them more evenly matched against the Star Tugs. The series also suggests there are lots of other tugs, and there are plenty of locations in and around the port that we haven't seen yet. And then there's the many background characters that were never developed during the series run.
* ''WesternAnimation/WinxClub'' allows the creation of infinite Sailor Earths, as each planet of the Magic Dimension can have as many Guardian Fairies as needed, not counting the [[DarkMagicalGirl Witches]] nor the [[KnightInShiningArmor Specialists]]. And even when the show has its own share of fanfics, its visual and fashion-centered approach prompts the fandom to create new fairies with their own [[http://janekim.deviantart.com/art/Jane-Kim-Enchantix-92522705 outfits]] and their [[https://www.youtube.com/watch?v=lh9yI57pqSY&feature=related own]] [[https://www.youtube.com/watch?v=FZBttzyyEG0 transformations]]. And yes, there is such a thing as [[http://waliafairy.piczo.com/?cr=3 Sailor Enchantix]] and [[http://novascorpion.deviantart.com/art/Enchantix-Moon-68652046 Enchantix Moon]].
* ''WesternAnimation/{{WITCH}}'' being similar to ''Franchise/SailorMoon'' (five girls chosen to be [[MagicalGirlWarrior Magical Girl Warriors]] as part of an ancient tradition) gives plenty of fodder for entire teams of original characters with [[FunWithAcronyms team names made of the first initials of the characters]] in fanfics and fanart. There is even a fan-created electronic paper doll makers so users can create a Guardian [[http://hapuriainen.deviantart.com/art/W-i-t-c-h-guardian-maker-167755079 here]].
* ''WesternAnimation/XiaolinShowdown'' gets this a lot too, though the fanfics seem to be split evenly between making a new kid show up, or making Jack a Xiaolin monk as well. As with the ''Anime/DigimonFrontier'' example above, this always involves making a "new element". The most common choices are metal, plants/flowers, and on occasion, [[WhatKindOfLamePowerIsHeartAnyway Heart.]] The follow-up series, ''WesternAnimation/XiaolinChronicles'', does exactly this by introducing Ping Pong, the Xiaolin Dragon of Wood.
* Because of how common it is for ''WesternAnimation/XMenEvolution'' fans to create Original Characters, some people have advertised stories where the basic premise is 'Create your own OC for my new OC group of Students'. Bringing in characters who only appeared in the comics is also popular.
[[/folder]]

** Some fanfics of ''Kingdom Hearts'' may actually show an ''entirely'' new Organization surfacing from all that was ever left of the old one. Considering the "Twenty Years later, a new disaster causes a group of people to lose their hearts and create Nobodies" situation is, in theory, highly possible. [[spoiler:This is entirely canon. ''[[VideoGame/KingdomHearts3DDreamDropDistance Dream Drop Distance]]'' states Master Xehanort is reviving Organization XIII using himself as the leader and various incarnations of himself and other beings corrupted by him as the members.]]
** It used to be fairly common in fics to see a character being introduced as the fourteenth member of Organization XIII. Such characters became fairly easy to name as well, as members of the Organization's names are anagrams of their original names with an "X" thrown in somewhere. Such fics were often mocked, considering they're called Organization ''Thirteen''. But then ''VideoGame/KingdomHearts358DaysOver2'' came out, a midquel which revealed the Organization had actually ''had'' a fourteenth member, and {{deconstruct|ion}}ed the entire concept.
** Chances are you'll find new types of Heartless and Nobodies in fanfics. Given that most of the Nobodies are based on a ''Franchise/FinalFantasy'' job class in name and abilities, creating new types is fairly simple. Besides, it is strongly suggested that there were five more classes of Nobodies that were never seen. Discounting the Twilight Thorn and Gummi Ship enemies, ten types of Nobodies were in ''VideoGame/KingdomHeartsII'': two common types (Dusks and Creepers) and one type of minion for each of the eight Organization members still alive at the beginning of the game. There is no logical reason why the five who were killed [[VideoGame/KingdomHeartsChainOfMemories at Castle Oblivion]] wouldn't have had their own minions. ''VideoGame/KingdomHeartsIII'' would eventually reveal two of the "missing" types: Reaper (belonging to [[spoiler:Marluxia]]) and Ninja (belonging to [[spoiler:Larxene]]). The other three remain unaccounted for, even with [[spoiler:both Demyx and Vexen ([[TheMole sort of]]) showing up as backup members for the True Organization]].

* The initial cast of ''VideoGame/KantaiCollection'' featured girls who were [[AnthropomorphicPersonification the spirits of warships]] that were part of the Imperial Japanese Navy. Naturally, fan works tended to take advantage of this by adding shipgirls from other countries' naval forces, particularly [[UsefulNotes/WorldWarII the U.S. Navy]] (''FanFic/PacificWorldWarIIUsNavyShipgirls'' being one such). The game's gradually started adding its own foreign shipgirls, but even so, there's still a huge number of potential shipgirls available for fans.

** Ultimate talents don't even have to be all encompassing: [[Characters/DanganronpaV3FemaleStudents Kaede Akamatsu]] is the Ultimate Pianist even though [[Characters/Danganronpa2FemaleStudents Ibuki Miuda]] is the Ultimate Musician, since Ibuki focuses mainly on rock music. So for example, if you want your original character to be the Ultimate Dancer even though [[Characters/Danganronpa2FemaleStudents Hiyoko Saioniji]] is already the Ultimate Traditional Dancer, it's allowed if you make your OC's talent be based around modern dancing instead.

* ''WesternAnimation/{{Nine}}'':
** Fans tend to create their own stitchpunks with numbers of 10 and higher. Which may or may not totally defeat their original purpose, or maybe the fans just imagine themselves to be the scientist's partners who all decided to band together and create an army of stitchpunks for a more likely chance of destroying the machine, or... whatever, my brain hurts.
** Another common practice is creating a stitchpunk named 0, who is almost always a prototype created by the scientist or an elder stitchpunk created alongside 1 and 2.

* ''Film/RealSteel'' introduces a world where boxing is now done between robots. Each robot has a different theme, and many of them are implied to be homemade. All a fanfic writer would need to do is create a robot, and give it a BackStory. The film and additional material related to it give many facts for {{Worldbuilding}} as well; for example, robot boxing originated in Japan.

* There are quite a few ''Franchise/{{Ghostbusters}}'' franchises within the United States and worldwide, many of whom do charity events, fundraisers, and the like.

* ''Film/PacificRim'' has, at the time it takes place, every single [[HumongousMecha Jaeger]] accounted for. However, in the fictional history of TheVerse up to that point there have canonically been many Jaegers, not all of which are named or described, but all of which can be identified by a few key points. They each have a nation of origin (which is not necessarily the same nation of the pilots or its area of operation), and a generation designation from mark one to mark five. Creating one involves picking a nation, a mark, and giving it a word-salad name, and it can probably slip into existing canon easily enough. Same goes for {{Kaiju}} for them to fight, who range in size from category one to category five and often have a Japanese name. In fact, the [[http://www.pacificrimmovie.com/ website]] even had a minigame specifically designed for this: you could mix and match parts from all the existing Jaegers, input a name and nation of origin, and you could make your own fanmade poster for the film.

* Making a ''Film/{{Descendants}}'' character can be ridiculously easy; just pick a Disney Animated Canon character (hero or villain), give them a kid, and give the kid a name similar to that of the character you picked. If you don't want to use a Disney film as your basis, just pick any one of their numerous animated shows. If you're feeling ''really'' ambitious, you could use characters from Disney properties like ''Franchise/StarWars'' or [[Franchise/MarvelCinematicUniverse the MCU!]]
* There are numerous ''Franchise/{{Godzilla}}'' fan works that introduce at least one all-new {{kaiju}}.
* ''Film/BrightBurn'' only has [[spoiler: 3 CorruptedCharacterCopy characters]], but all you gotta do is take a superhero and turn them evil to create an oc.

* ''WesternAnimation/WreckItRalph'':
** Plenty of fans have come up with their own ''Sugar Rush'' racers. All you need to do is make a boy or girl that wears a dessert, confectionery creation or any sort of sweet food themed clothing, and then give him or her a ridiculous name. A bit like ''WesternAnimation/StrawberryShortcake'' but with a CoolCar.
** Don't like racing? Just have the arcade get a new machine added with your favorite game! You can import any naming theme you want that way.

* ''Franchise/{{Transformers}}'' makes this even easier, even if you don't take a [[MerchandiseDriven toy that never got to the screen]] or one of the base characters not already in that reboot, and characterise it for yourself. Pick a cool alt for your OriginalCharacter (thanks to Hasbro, even Triple Changers are allowed now) and a name that fits the "CodeName as real name" motif (there's freaking name generators out there), and you're [[StealthPun ready to roll out]]. You don't even need to say ''why'' they're there, because they're there for the same reason everyone else is there -- there's a war, dammit! This is okay because Hasbro uses the same method for inventing their own toy-only characters -- and their not-toy-only characters -- and the writers of the various cartoons, comics, and other fiction use it for their [[ToylessToylineCharacter non-toy characters]]. It's one of the few fandoms where the "Sailor Earth" approach is not only acceptable, but accepted as standard operating procedure.
** ''WesternAnimation/BeastWars'' has the question of the unrecovered stasis pods, which leads to the uniquely FandomSpecificPlot of Beast Warriors continuing the fight on other continents (to explain characters with non-African beast modes), or long after the show ended (some of the comics operated on this concept).
** ''Anime/TransformersCybertron'' has the various themed Planets with their Cyber Keys as a core concept. Some fans have taken to creating their own Planets with various potential factions and alternate modes represented--popular ones include 'sky worlds,' typically a WorldInTheSky that favors aerial alternate modes, and 'water worlds' for aquatic modes.
* ''WesternAnimation/InvaderZim'' is prone to acquiring new Invaders. Or Tallest, if you're feeling ambitious. The creator explicitly mentioned this on the DVDCommentary, saying he would enjoy going to the homes of the little kids who believe they're "Invader Tom" or "Invader Sally" and wrecking their dreams by noting they weren't at the Great Assigning (every Invader, even those that didn't appear, are accounted for). Note that these new Invaders, or any other Irken [=OCs=], almost inevitably wind up going to Earth and ending up in Ms. Bitters' class. Which seems awfully familiar to anyone who watched the "Tak" episode. Also, an alarmingly high portion of these new Irkens have blue eyes -- which is explicitly stated to be impossible in-universe.

* With Stitch from ''WesternAnimation/LiloAndStitch'' being Experiment 626, fans had approximately 625 remaining experiments to come up with for themselves. However, ''[[WesternAnimation/LiloAndStitchTheSeries The Series]]'' (as well as some tie-in comics published in ''Magazine/DisneyAdventures'' and the ''Anime/{{Stitch}}'' anime made some time later) showed some of these experiments and ''The Series''[='=] [[WesternAnimation/LeroyAndStitch finale movie]] listed [[Characters/LiloAndStitchExperiments all 625 of the other experiments]] made prior to Stitch in the credits. All that has done was make giving your fan-made experiment a name and number unnecessary now. Even then, fans often tend to ignore the admittedly bland or ridiculous names for the unseen experiments in favor of just going with whatever they want for their "experiment-sonas"/"Stitch-sonas".

* Since there are only three official ''[[WesternAnimation/ThePowerpuffGirls Powerpuff Girls]]'' around, in came a rainstorm of PPG [[OriginalCharacter OC]]s, mostly being Powerpuffs for any other color besides pink, blue and green. When it's not the rest of the rainbow, it's just a new-and-improved Bunny brought BackFromTheDead and beautified, or sometimes it's the introduction of new Rowdyruff Boys (usually in stories where the original ones had a HeelFaceTurn). One of the most well-known Powerpuff Sailor Earths around is Bell, the white Powerpuff from the ''Webcomic/PowerpuffGirlsDoujinshi'' by Bleedman. Even then, she's an antagonist.

* Shoehorning new Lyoko Warriors into the group in ''WesternAnimation/CodeLyoko'' fic is all too common, as they are in a whole school full of potential new warriors, and they have endless need for new help.
* ''WesternAnimation/TeenTitans'' fandom contains PLENTY of fics where a new girl or boy (far more rare) shows up in Jump City with powers and joins up as the [[SixthRanger sixth Titan]].
** Plenty of these new Titans seem to indeed be Terra clones, in that they're either working for or related directly to Slade. OriginalCharacter apprentices were a dime a dozen for quite a while.
** The series ends on a very open-ended note, leaving that opportunity wide to the masses to make something of the sort.
** Another popular route to take when creating Teen Titans [=OCs=] is to make a Titans North or Titans South (or a Titans Whatever-country-or-continent-suits-the-story's-purposes), using Titans East as both justification and inspiration. This way, an entire team of new characters can be made without interfering with canon too much. Yet another option is to add a [[SixthRanger sixth Titan]] to Titans East (some might not even consider them a "sixth" member, claiming that Mas and Menos count as one Titan) to pair them off with Speedy or Aqualad. And of course, it's perfectly reasonable and very popular to simply create new [=OCs=] that are Honorary Titans, residing wherever they want and tied down only to a duo at most. And that's just when it comes to creating heroes. Villains and neutral characters are popular among creators too; after all, what fun is a new hero without a new archenemy to wipe the floor with? So in all honesty, Teen Titans is among the easiest fandoms to create characters for, no matter how the creator decides to pull it off.
* ''WesternAnimation/AvatarTheLastAirbender'':
** The cartoon finishes on something of a cliffer. Though this was expanded upon later in the SequelSeries ''WesternAnimation/TheLegendOfKorra'', there are many fics that attempt to write a ''Book 4: Air'' (which would make sense, considering how much the show focused on the four elements).
** There are tales about a ''previous'' Avatar: Pretty easy to do, since we don't know how may Avatars there have been and we only know the names of nine of them: Aang, Korra, the five Avatars immediately preceding Aang (Roku, Kyoshi, Kuruk, Yangchen, and Szeto), Salai (a historical Avatar mentioned in passing in ''Literature/TheRiseOfKyoshi'') and the first Avatar, Wan.
** Another variation is a story about the complete learning cycle of a later Avatar, anywhere from directly after Aang or Korra to an Avatar in a modernized setting. Very rarely it inverts the concepts and has an Avatar living in a futuristic space age.
* ''WesternAnimation/{{Recess}}'' always has the possibility for "The New Kid", or any other of the nameless kids (or their nicknames) present on the playground. It wouldn't be that hard for something like "The Slide Climbing kid" or "The Video Game Kid".
* ''WesternAnimation/WinxClub'' allows the creation of infinite Sailor Earths, as each planet of the Magic Dimension can have as many Guardian Fairies as needed, not counting the [[DarkMagicalGirl Witches]] nor the [[KnightInShiningArmor Specialists]]. And even when the show has its own share of fanfics, its visual and fashion-centered approach prompts the fandom to create new fairies with their own [[http://janekim.deviantart.com/art/Jane-Kim-Enchantix-92522705 outfits]] and their [[https://www.youtube.com/watch?v=lh9yI57pqSY&feature=related own]] [[https://www.youtube.com/watch?v=FZBttzyyEG0 transformations]]. And yes, there is such a thing as [[http://waliafairy.piczo.com/?cr=3 Sailor Enchantix]] and [[http://novascorpion.deviantart.com/art/Enchantix-Moon-68652046 Enchantix Moon]].
* Every version of ''WesternAnimation/StrawberryShortcake'' also allows the creation of infinite Sailor Earths. The characters are named for food. Limitless, eh?
* It's not hard to have [=OCs=] for ''WesternAnimation/CodenameKidsNextDoor''. Just pick a number. Or become a member of the Safety Patrol. Or be delightfullized. Be CrazyAwesome as a child or teenage character. Make some sort of villain (just come up with a concept you dreaded as a kid).
* The ''WesternAnimation/TotalDrama'' series, by virtue of having its contestants based on teen and elimination game stereotypes, is particularly suited to such knockoffs:
** Remakes of the first season often have one or two new characters join the canon cast. If there is only one, it will usually be an AuthorAvatar.
** Stories set in new seasons tend to use ostensibly original characters that have [[SuspiciouslySimilarSubstitute remarkably similar characteristics]] to the canon cast. This is easily--sometimes explicitly--justified with the conceit that the in-universe producers are screening for certain types, and [[Administrivia/TropesAreTools has the benefit]] of freeing the writer from having to acknowledge canon relationships, for example.
** More audacious fics such as ''[[Fanfic/TotalDramaComebackSeries Total Drama Battlegrounds]]'' may introduce a whole new cast of stereotypes while keeping the original cast as well.
* ''WesternAnimation/XiaolinShowdown'' gets this a lot too, though the fanfics seem to be split evenly between making a new kid show up, or making Jack a Xiaolin monk as well. As with the ''Anime/DigimonFrontier'' example above, this always involves making a "new element". The most common choices are metal, plants/flowers, and on occasion, [[WhatKindOfLamePowerIsHeartAnyway Heart.]] The follow-up series, ''WesternAnimation/XiaolinChronicles'', does exactly this by introducing Ping Pong, the Xiaolin Dragon of Wood.
* Many ''WesternAnimation/RoadRovers'' fans loved creating their own, by simply picking a breed, gender, nationality, and maybe superpower.
* Another fandom that makes this easy is the ''WesternAnimation/StormHawks'' fandom. All you need is to either pick a pre-existing species (Merbs are the most common in fanfiction) and pick the name of a bird. Most of these also tend to be a love interest for Stork, of all people...
* ''WesternAnimation/{{Tugs}}'' revolves around two fleets of tugs. To introduce a new character, all that's needed is for one of the fleet's captains to suggest that they need another tug because there's too much work, or (in the case of the Z-Stacks) to make them more evenly matched against the Star Tugs. The series also suggests there are lots of other tugs, and there are plenty of locations in and around the port that we haven't seen yet. And then there's the many background characters that were never developed during the series run.

* Because of how common it is for ''WesternAnimation/XMenEvolution'' fans to create Original Characters, some people have advertised stories where the basic premise is 'Create your own OC for my new OC group of Students'. Bringing in characters who only appeared in the comics is also popular.

* Comes up from time to time in ''WesternAnimation/ThunderCats'' fanfiction, both for the OS and the [[WesternAnimation/ThunderCats2011 reboot]]. There are many cat species not used in the show for writers to choose from. Add in how the reboot expanded on the species of the other animal races, and there are even more possibilities.
* ''WesternAnimation/AdventureTime'' has a large cast of [Noun] [Royalty]s, especially [[GratuitousPrincess princesses]], so it's not that hard to invent a new one. Oddly, the most popular kind of OC seems to be an Ice Prince(ss), who is generally either the child or niece/nephew of [[AnIcePerson the Ice King]] (which makes little sense given what we know about him in canon). Long-lost relatives of [[EmperorScientist Princess Bubblegum]] and other humans (sometimes serving as love interests for Finn to fill the void left following his break-up with Flame Princess) are also fairly common.
* ''WesternAnimation/{{WITCH}}'' being similar to ''Franchise/SailorMoon'' (five girls chosen to be [[MagicalGirlWarrior Magical Girl Warriors]] as part of an ancient tradition) gives plenty of fodder for entire teams of original characters with [[FunWithAcronyms team names made of the first initials of the characters]] in fanfics and fanart. There is even a fan-created electronic paper doll makers so users can create a Guardian [[http://hapuriainen.deviantart.com/art/W-i-t-c-h-guardian-maker-167755079 here]].
* The abundance of British locomotive types has made making original characters for ''WesternAnimation/ThomasTheTankEngine'' extremely easy. Road vehicles, boats, planes, humans, even non-British locomotives are also no-brainers, to the point that foreign locomotives like Hank, Bash, Dash and Ferdinand (USA), Flora (Ireland), Hiro (Japan), and Millie (France) are canon.

* There are an insane amount of ''WesternAnimation/SouthPark'' fanfics that involve a new kid (usually female) moving to town and becoming friends with the four main boys. If the character is a girl, as is the case with 99% of these stories, a romantic relationship is guaranteed, with Kyle being the most popular boy to pair her with.
** Interestingly, the official video game ''VideoGame/SouthParkTheStickOfTruth'' opens with this plot (minus any romance).
* ''WesternAnimation/ChipNDaleRescueRangers'' fanfics often feature {{Original Character}}s who just happen to also be crime-fighting rodent vigilantes who end up teaming up with the Rangers to solve some big case, normally joining the team in the process. Less common are rival crime-fighting groups, though these do pop up occasionally (more often in official comic spinoffs than in fanfics). It seems to be the goal of many fanfic writers to eventually add more and more characters to the Rangers, to the point that, for every nonvillainous character on the show (and some villainous ones), there is probably a fanfic somewhere where they join the team (Foxglove, Tammy, and occasionally Sparky are the most common targets of this). Add to this all the AuthorAvatar characters who have joined the team, and the roster probably numbers in the dozens, if not hundreds.
* ''WesternAnimation/{{Mixels}}'' has a lot of fan-created tribes based on different themes and elements. Most of the time, they contain female members. Interestingly, for this series LEGO actually ''encourages'' the fans to create their own works with the Mixel sets, thanks to their FusionDance gimmick.
* ''WesternAnimation/MiraculousLadybug'':
** Writers are often ''required'' by the plot to create {{Original Character}}s to be akumatized. Unusually, this functions to keep the story more focused on Ladybug and Chat Noir, as akumatizing any existing characters would require more narrative focus than just having a random person show up for a plot-mandated fight.
** The Miraculous holders. Fanartists tend to either invent brand new miraculouses and Kwamis, based on varied animals, and their holders; or to represent the people who could have the non-used jewels seen in the credits: the fox, the peacock, the bee, and the turtle. [[spoiler: Or at least non-used in season one. Since then, it's been revealed that the turtle, the fox, the bee, and the peacock holders are respectively Master Fu and Nino, Alya, Chloe, and Mayura.]] The episode "Sapotis" also reveals the existence of an additional ''dozen'' Miraculous beyond the main seven, corresponding to the animals of the EasternZodiac. [[spoiler:And then the episode "Feast" revealed that there are more miraculous boxes than the one that contains the nineteen known ones, and it's implied there's a lion miraculous among them.]]
** The American special reveals that there is a Miraculous set based on Native American culture, with Jess gaining the Eagle Miraculous, and WordOfGod revealing the identites of the others. It's not too hard for a fanfiction writer to come up with holders for those Miracuoluses.
* It's pretty easy to create a fan-character for ''WesternAnimation/{{Trollz}}'', due to the RockThemeNaming. Emerald is a particularly popular choice, as green isn't on the color spectrum the girls have.
* ''WesternAnimation/CaptainPlanet'' -- only five of the continents (Africa, North America, South America, Europe and Asia) are represented in canon, so it's not hard to create Planeteers who come from Australia, Oceania, maybe even Antarctica, Central America and Western Europe, as Linka represents Eastern Europe. Just give them a new element, and there you go.
* ''WesternAnimation/Foot2Rue'' -- we never see Tag's mom, Eloise's male relatives, Samira's brothers and sisters, Lil Dragon's dad or Jeremy's younger half siblings, so there's plenty of OC potential there.
* Want to create an original character for ''WesternAnimation/BuzzLightyearOfStarCommand''? All you have to do is decide if you want them to be human or alien and whether or not you want them to be a Space Ranger. Simple.
* ''WesternAnimation/TheLoudHouse'': A number of {{Original Character}}s are more siblings, cousins, or [[FanCreatedOffspring children]] of the pre-existing Louds that are shoehorned into the already full household. Naturally they have names starting with the letter "L".
* ''WesternAnimation/OKKOLetsBeHeroes'': Since the world is full of [[FantasyKitchenSink fantastical people]], such as [[OurMermaidsAreDifferent mermaids]], [[OurGhostsAreDifferent ghosts]], [[OurWerewolvesAreDifferent werewolves]], etc., and chock full of villains and heroes, it's quite easy to make your own character. The creators of this show even [[https://ok-ko.tumblr.com/post/161861408154/official-pow-card-template-for-your-ok-ko-oc-one made an official template for OCs.]]
* To create a [[GangOfHats Mute group]] for ''WesternAnimation/KipoAndTheAgeOfWonderbeasts'', just pick an animal species to [[FunnyAnimal anthropomorphize]] and give them some sort of theme and an associated style of music.
* All characters in ''WesternAnimation/{{Chowder}}'' are named after food, so Chowder {{Original Character}}s tend to follow this pattern.

* To create an [[GangOfHats Mute group]] for ''WesternAnimation/KipoAndTheAgeOfWonderbeasts'', just pick an animal species to [[FunnyAnimal anthropomorphize]] and give them some sort of theme and an associated style of music.

* ''WesternAnimation/ChipNDaleRescueRangers'' fanfics often feature original characters who just happen to also be crime-fighting rodent vigilantes who end up teaming up with the Rangers to solve some big case, normally joining the team in the process. Less common are rival crime-fighting groups, though these do pop up occasionally (more often in official comic spinoffs than in fanfics). It seems to be the goal of many fanfic writers to eventually add more and more characters to the Rangers, to the point that, for every nonvillainous character on the show (and some villainous ones), there is probably a fanfic somewhere where they join the team (Foxglove, Tammy, and occasionally Sparky are the most common targets of this). Add to this all the AuthorAvatar characters who have joined the team, and the roster probably numbers in the dozens, if not hundreds.

* All characters in ''WesternAnimation/Chowder'' are named after food, so Chowder fan characters tend to follow this pattern.

So why do Sailor Earths pop up in a given work? Human beings are naturally completionists when it comes to patterns, so if a work feels like an element is missing from it, be it a certain role, personality, skill-set or an actual power, then fans will come in and fill the missing "element". Oftentimes the creators would end up filling that role anyway, leading fans to exclaim IKnewIt or disappointed that [[OutdatedByCanon their predictions have been invalidated]].

So why do Sailor Earths pop up in a given work? Human beings are naturally pattern completionists, so if a work feels like an element is missing from it, be it a certain role, personality, skill-set or an actual power, then fans will come in and fill the missing "element". Oftentimes the creators would end up filling that role anyway, leading fans to exclaim IKnewIt or disappointed that [[OutdatedByCanon their predictions have been invalidated]].

*** Double? You don't even have to invent new memories from whole cloth. What if Philip and Shotaro used another Rider's Gaia Memories? Or even Dopant Memories? Nazca and Skull are pretty popular choices for those [[spoiler:and Accel is even teased in the show, having Shroud's intention being to fuse Accel and Double's powers together]]. Canonically speaking, however, the existence of alternate Fang combos was effectively {{Jossed}} by the Double novel, where it's explained that Shotaro's compatibility with the Joker Memory lets him put a leash on Fang's berserker tendencies; any other combo would result in Double becoming uncontrollable.