->'''Infected Wall-nut:''' Here's an idea! Instead of standing out here and guarding this guy´s house we go IN his house and eat his brains!\\
'''Peashooter:''' Yeah! Yeah! Go in there and eat his bra- wait what?\\
'''Sunflowers:''' Yup, definitely a zombie.\\
'''Infected Wall-nut:''' Oh wow, ok uh, I can so prove I'm not. Just lean over here, and I'll take a little nibble out of your plant-brain.
-->-- Dorkly, ''VideoGame/PlantsVsZombies''

A character, frequently a protagonist, is turned into the very thing he or she has been fighting; a survivor of a ZombieApocalypse may get [[TheVirus bitten by a zombie]], a demon hunter may be [[DemonicPossession possessed]], and so on. Unlike HeWhoFightsMonsters, where the hero metaphorically becomes like the evil he was fighting, this is a literal transformation into an actual monster.

Played straight, implies a FaceHeelTurn (but see below). If the transformation in question isn't generally seen as evil or monstrous, that's more of a ViralTransformation.

Tends to be something of an EndingTrope, since it's more dramatic to have the hero succumb at the end of an epic struggle to fight the zombies/monsters/whatever. If there's no way back, that can make it a DownerEnding. May also be the result of a HeroicSacrifice.

A popular variation of this is for protagonists to have this thrust on them as an EmergencyTransformation,
and/or (attempt to) use HeroicWillpower to avoid the FaceHeelTurn frequently associated with this trope. If that works, the hero can use the powers [[CursedWithAwesome for the cause of good]]. Results of such attempts vary. It is also possible for this to happen to villainous characters. Depending on the villain and the type of transformation in question, results vary -- even more than heroic characters -- but it can then result in a HeelFaceTurn.

The TropeNamer is an infamous bad short fanfiction called ''DoomRepercussionsOfEvil'', where the protagonist, named John, suddenly turns into a Zombie with no explanation whatsoever.

If poorly foreshadowed (as with the trope namer), this can very easily be a ShockingSwerve. When explicitly foreshadowed, the hero was a DoomedProtagonist[[labelnote:*]]no relation to Doom[[/labelnote]]. When it's suddenly revealed that the main character ''was'' a monster all along, that's TomatoInTheMirror. Often happens when the antagonist of the story was TheVirus or TheAssimilator.

'''Examples will contain spoilers!'''
----
!!Examples:

[[foldercontrol]]

[[folder: Anime and Manga]]
* The [[{{Claymore}} Claymores]] who become Awakened Beings definitely qualify. Particularly galling in the case of Ophelia, as she ''really'' hates Awakened Beings, and became a Claymore to fight them. [[spoiler: And Then Cassandra, Hysteria and Roxanne Became Awakened Beings after they were resurrected.]]
* In ''Anime/DigimonSavers'', the main human villain, Kurata, has a great fear of all Digimon and kills a bunch of them in the name of one-sided peace, but then uses their life force to power an even worse villain-type Digimon and become one with it [[MotiveDecay to ultimately take over the world]].
* In ''GensoumadenSaiyuki'', Hakkai slays a thousand demons and his thousandth turns him into a demon, pointy ears and all.
* In ''{{Kakurenbo}}'', the main character wins the game of hide-and-seek by being the last child to be found... and then is given the honor of being the new "it", that is, he becomes a demon himself.
* ''KannazukiNoMiko'': And then Souma was a [[TakenForGranite petrified]] Orochi. He saw it coming, though, and try to use the Orochi powers contaminating his body to make a HeroicSacrifice. He recovers later.
* ''Anime/PuellaMagiMadokaMagica'':
** {{Magical Girl}}s fight monsters known as witches. When defeated, these witches drop a Grief Seed which the magical girls use to cleanse their soul gems, which get gradually darker every time they use their powers or suffer sadness and despair. [[spoiler:What Kyubey doesn't mention is that when the soul gems turns completely black they will turn in a witch. Every magical girl who doesn't die in battle will eventually become a [[EldritchAbomination Witch]], the monsters that the magical girls fight throughout the series, and their Soul Gems become Grief Seeds, thus perpetuating a vicious cycle]]. This is illustrated in Episode 8 when this happens to [[spoiler:Sayaka]].
** [[spoiler: Even before you become a Witch, there is still some opportunity for horror. The Soul Gems in question? [[SoulJar Their name is literal]]. Since your soul is outside your body, that essentially makes you a girly, sparkly [[OurLichesAreDifferent Lich]]. The girls find this out the hard way when Sayaka's soul gem is thrown too far away from her body, causing her to fall over dead until it is returned to her. She then considers herself inhuman and this accelerates her inevitable transformation into a Witch.]]
* In ''SchoolMermaid'', the main character ends up being pulled down into the floor by the very mermaids she was hunting and becomes one herself. And it is strongly implied that her best friend will hunt her down and eat her later.
* In ''ShikabaneHime'', [[spoiler:Ouri turns out to be part Shikabane]].
* In ''{{Shiki}}'', [[spoiler: almost every character ends up as a vampire, including two of the three protagonists]].
* In ''Manga/{{Uzumaki}}'', after the teacher smashes a bunch of human hybrid snail eggs in disgust, he returns a week later a snail man. With a bunch of snail eggs growing on his back.
** In the end, [[spoiler: Kirie and Shuichi become spirals]].
* In ''Manga/AttackOnTitan'', members of the 104th Trainee Corps encounter an Rogue Titan that only attacks other Titans. It's actually [[spoiler: Eren]], as he's able to create and "pilot" a Titan body. [[spoiler: He's not the only one. Reiner, Bertolt, and Annie all turn out to be Titan Shifters sent from somewhere outside the Walls, with the mission to infiltrate the military and exterminate "mankind within the Walls". Eren's transformation changes their mission, with them attempting to kidnap him. Reiner claims they no longer intend to carry out the extermination. Ymir is also a Titan Shifter, but comes from somewhere else, suggesting at least ''two'' separate groups of Titan Shifters outside the Walls.]] The secret experiments [[spoiler:Eren]]'s father was carrying out in his basement may be the reason behind his powers.
* ''Manga/{{Bleach}}: When Ichigo invades Hueco Mundo to rescue Orihime, he repeatedly comes into conflict with Ulquiorra, handling each new fight better than last time. Ulquiorra accuses him of becoming more like a hollow but Ichigo retorts that, to him, it seems like Ulquiorra is becoming more human. Unfortunately for Ichigo, their climactic battle sees Ichigo transform fully into a monstrous hollow and not only rip Ulquiorra's body apart but also stab his friend Uryuu for attempting to restrain his hollowfication blood lust.
* Used to an extent in ''Manga/SoulEater'' as several protagonists (mostly Stein but Maka, Soul, Black Star and Death the Kidd have been subject to this too) get taken over by their own insanity, their infected black blood or just an eldritch abomination that drives them insane
* In ''Manga/DragonBall'' early in the Buu saga, everyone is told that Babidi can take the smallest seed of evil in someones heart and corrupt them to work for him. The people who go into his ship to fight him are a God, Goku and Gohan (who are repeatedly shown to be pure of heart and can ride the flying Nimbus) and Vegeta, who claimed to have become a super saiyan by having a heart of pure evil. It's not hard to guess who ends up selling his mind to Babidi for a chance to fight his rival on equal terms (though interestingly he still retains enough of his will to ignore the other two despite being ordered to kill them too)
* [[spoiler:Furuichi]] in ''XamdLostMemories'', who is of the show's most outspoken human supremacists and someone who deeply loathes the Xam'd, is transformed into a Xam'd halfway through the series. [[spoiler:He commits suicide before his transformation is completed.]]
[[/folder]]

[[folder:Card Games]]
* ''MagicTheGathering'' gives us Karn, a golem created to fight the Phyrexians. But his heart was a Phyrexian stone, normally used for insta-YouHaveFailedMe. This stone contained, like all artifacts of Phyrexian origin, [[FromASingleCell the oil]], which took hold on Mirrodin. Karn [[SubvertedTrope almost gave in]] to the Praetors' whispers.
** The Innistrad Block has a fetish for these, and with good reason, as the story line has nearly all monstruousities coming from mankind. In particular, "church warrior becomes zombie" seems to be very popular.
* Some ''TabletopGame/YuGiOh'' cards have images that tell stories.
** One is the Gagagigo series; it starts as the Gigobyte, who wants to fight monsters... and ends with Gogiga Gagagigo, whose soul has ceased to exist and his body only moves on a drive for power.
** Then there's Warrior Dai Grepher; the first card of his story shows him and other warriors and spellcasters fighting demonic creatures. Then the series goes on and he becomes Dark Lucius. In Sakuretsu Armor, Dark Lucius LV6 can be seen striking down some of the people he fought alongside in that first card.
** Gigobyte starts down the road to [[StartOfDarkness evil soulessness]] by modifying himself to get more power to defeat the [[BigBad Invader of Darkness]]. Since the story is spread over the flavor texts of many cards over a few different expansions, it doesn't come as too much of a surprise. The compiled story is [[http://yugioh.wikia.com/wiki/Card_Trivia:Gagagigo here]] if you're interested.
[[/folder]]

[[folder:Comic Books]]
* The ending of ''ThirtyDaysOfNight'' involves the hero, Eben Oleson, turning himself into a vampire to save his friends. This counts because the vampires invaded to feed, not to create new vampires and the humans (until that point) weren't interested in becoming vampires.
* In the fictional comic book ''Tales of the Black Freighter'', a story within a story from ''Comicbook/{{Watchmen}}'', the protagonist [[spoiler:mistakenly bludgeons his wife almost to death while attempting to save her and his family from undead pirates. The pirates only want him though, and the story ends ambiguously with the protagonist either being killed by the pirates or becoming one. His last words are "I was a horror; amongst horrors must I dwell".]]
* In ''ComicBook/TheSmurfs'' story "The Black Smurfs" (and its AnimatedAdaptation [[WesternAnimation/TheSmurfs counterpart]] "The Purple Smurfs"), Papa Smurf is the only Smurf left in the village after the Black Smurf disease had turned all of his little Smurfs into Black Smurfs (the Smurf analog to zombies). When Papa Smurf rushes to his laboratory to get more tuberose pollen, a Black Smurf disguised as a blue Smurf bites Papa Smurf in the tail and infects him, causing him to turn black as well. [[spoiler:The Smurfs are saved completely by accident; he knocks the vat of pollen over, and it spreads over the village, curing them.]]
[[/folder]]

[[folder:Eastern Animation]]
* At the end of the short ''HisWifeIsAHen'', the husband [[HenpeckedHusband becomes a chicken]].
[[/folder]]

[[folder:Fan Works]]
* This trope is named for the legendary CruelTwistEnding of the fanfic ''FanFic/DoomRepercussionsOfEvil'', wherein John Stalvern, who has spent the story fighting demons, becomes a zombie himself. (Or possibly was a [[TomatoInTheMirror zombie from the beginning]], fooled by Satanic illusions into seeing humans as demons. It's not [[MindScrew totally clear]].)
** [[http://fanfictionredux.ytmnd.com/ Now with dramatic reading -- brought to you by YTMND.]]
** [[http://www.fanfiction.net/s/4067416/1/Doom-Repercussions-of-Evil-Mark-II This]] beautiful piece is a rewritten version that both triples (or something) the length of the original story AND gives it a better feel overall. Still not as good as [[SoBadItsGood the original]], though.
** And then there's [[http://youtu.be/PGkrrT1VtsU?t=6m49s this version]]
** Also a [[http://www.youtube.com/watch?v=08l0DnKBZBo song version.]]
* {{Fanfic/Zombies}} has multiple cases of DecoyProtagonist syndrome. But finally, Princess Peach and Sonic seem to be the BigDamnHeroes of the story [[spoiler: until they both succumb to their infections and devour their allies viciously]].
* ArbyNTheChief: And then, JOHN WAS THE ALIENS!
* In the ''Manga/FullmetalAlchemist'' fangame ''Bluebird's Illusion'', Ed becomes a homunculus in one of the endings.
* In the ''Film/HowToTrainYourDragon'' fic ''[[http://www.fanfiction.net/s/6095775/1/ Cursed]]'', Hiccup [[spoiler: turns into a Night Fury]].
* In ''Grandma Got Bitten By A Vampire'' (a fan sequel to the animated ''WesternAnimation/GrandmaGotRunOverByAReindeer''). Daphne manages to cure her family of vampirism back to normal [[spoiler: only to find that their dog, Doofus, was turned and he promptly attacks and feeds on her. What's more Grandma had made friends with the vampire who bit her and liked being undead (as she was in her twilight years anyway) and thus regained her vampirism. Re-vamping Jake (who was initially against being a vampire) as well. The three decided to keep the secret from the family for the time being and enjoy terrorizing Cityville at night.]]
* In ''FanFic/{{Respect}}'': [[spoiler:This happens in a symbolic sense to [[Anime/SmilePrettyCure Yayoi]], who makes a [[DealWithTheDevil contract]] with [[Anime/PuellaMagiMadokaMagica Kyubey]] in order to stand up to the bullies that torment her. By the end, as Mami points out, she's become a villain, a "bully" herself, and being confronted with this sends her over the DespairEventHorizon. The trope then happens in a ''literal'' sense, as we see that Yayoi has transformed into Izabel, the Artist Witch from episode 10 of Madoka.]]
* ''Fanfic/EakinsHardReset'':
** [[spoiler: In the canon ending, the Elements of Harmony transform almost every changeling into a true pony permanently]].
** [[spoiler: In the alternate ending, Twilight willingly becoming a changeling in order to take over the hive]].
* In ''FanFic/ComingHome'', [[VideoGame/SilentHill2 James]] is trying to get away from Pyramid Head and Vatiel and get out of Silent Hill. In the end, [[spoiler: James is forcibly turned into a HumanoidAbomination and stays in Silent Hill for his father's life to be spared.]]
* In the ''WesternAnimation/PowerpuffGirls'' fanfiction, ''[[http://www.fanfiction.net/s/677859/1/Dead-Air Dead Air]]'' [[spoiler: Bubbles gets bitten in the middle of the story, in the end she turns into a zombie and attacks a sleeping Blossom, killing and eating her]].
* In the LandBeforeTime fanfiction ''Fanfic/TheSevenHunters'' all of the gang are [[spoiler:transformed into sharpteeth]].
[[/folder]]

[[folder:Film]]
* At the end of the ''Film/ThirtyDaysOfNight'' movie, the protagonist has to become a vampire in order to fight off the vampires that have been eating everyone. [[spoiler:He dies very shortly thereafter due to watching the sunrise with his girlfriend (so he'll die and not eat anyone).]]
* This is the whole plot point of BrotherBear. Kenai killing a bear out of sheer vengeance, [[RevengeBeforeReason despite the fact that his brothers death was a]] HeroicSacrifice, is what drives the spirits to [[BalefulPolymorph transform him into a]] [[KarmicTransformation bear]]. He can only get back to normal when he goes back to the mountain and gets his HeelRealization. [[spoiler: He later sees that he [[TearJerker killed Koda's mother]].]]
* A homage to such endings occurs in the 1996 ''Series/TalesFromTheCrypt'' movie, ''Bordello of Blood'' [[spoiler: Rafe saves his love interest, Catherine, from Lilith. Only at the end to find out Lilith managed to bite her in the thigh, conveniently hiding the bite mark from him. Catherine been undead since her rescue and proceeds to bite Rafe once she and him are alone.]]
* At the end of ''Film/{{Candyman}}'' the [[spoiler:heroine becomes a Candywoman]].
* At the end of ''Film/TheChroniclesOfRiddick'', Riddick [[spoiler:kills the Grand Marshall and becomes the new leader of the necromongers]], which was foreshadowed ''very'' strongly early on, [[spoiler:when Riddick is told that the Necromonger way was [[YouKillItYouBoughtIt "You keep what you kill".]]]]
* The ending of the 1970 film ''[[{{Film/CountYorga}} Count Yorga Vampire]]'' [[spoiler: The last survivor Michael manages to go to his girlfriend, Donna, and kill Yorga. After chasing off Yorga's remaining brides (one of which who was friend of theirs) Michael thinks its over. But just as he relaxes, Donna lunges at him, now a vampire herself, and kills him.]]
** A reversal of the kind of ending mentioned above occurs in the 1971 sequel, ''The Return of Count Yorga'', [[spoiler: Hayes manages to get past the vampire brides and confront Yorga. After a fight, Yorga is killed by Cynthia, a girl he was trying to turn. Cynthia hugs Baldwin only to pull away and reveal he's just now turned into a vampire himself. Baldwin promptly goes to bite her and bring Cynthia into the undead ranks he was trying to prevent not moments before.]]
* In the final scene of the movie ''{{Deadgirl}}'' we find out that the main character has become a [[spoiler:[[DoubleStandardRapeSciFi zombie]] [[DudeShesLikeInAComa rapist]]]] despite spending the entire movie trying to dissuade his friends from doing the exact same thing.
* In the ''VideoGame/{{Doom}}'' movie, Reaper is dying and his sister subjects him to the chromosome which had turned everyone else into monsters. [[DeusExMachina Luckily]] (and perhaps subverting this trope) he is among the small percent of humans who ''don't'' turn into monsters when exposed to it and instead become 'angels'.
* Occurs in ''Film/DragonballEvolution'' when Goku turns into the Oozaru, said to be an unstoppable servant of Piccolo, after having spent the movie determined to defeat Oozaru. Only after [[spoiler:killing Roshi]] does he get out of it. This is not the case in the original source material, where the Oozaru is not mentioned until Goku transforms for the first time.
* In the end of Creator/RomanPolanski's 1967 film ''Film/TheFearlessVampireKillers'' (and the subsequent 1997 musical adaptation, ''TanzDerVampire''), [[spoiler:the protagonists rescue the heroine from a pack of blood thirsty vampires, only to have her turn into one and attack the "hero" of the film at the very end.]]
* The [[ReCut Producer's Cut]] of ''Film/HalloweenTheCurseOfMichaelMyers'' ended with Dr. Loomis being marked with the [[TheCorruption Curse of Thorn]] to imply that he would carry on Michael's taint. This was one of many things dropped in the theatrical version, although this one happened because DonaldPleasence died.
** ''Film/Halloween4TheReturnOfMichaelMyers'' had this at the end with the little girl holding Michael's butcher knife, implying that she has become the new killer.
* Occurs in the 1983 film ''Film/HalloweenIIISeasonOfTheWitch''.
* The uber-creepy 1978 film of ''InvasionOfTheBodySnatchers'' ends with Veronica Cartwright's character approaching Donald Sutherland's character (he was the protagonist). As she calls out to him, he wheels around, points at her, and emits an inhuman wail (sort of the Pod People's call to arms).
* [[spoiler:Needy]] becomes part-demon after surviving Jennifer's attack in ''Film/JennifersBody''.
* At the climax of ''Film/TheOmegaMan'', Lisa becomes a part of [[EvilAlbino The Family]].
* ''Film/TheLairOfTheWhiteWorm'' ends with Hugh Grant's character lunging for another member of the cast after having been turned into a vampire.
* In the 1990 remake to ''NightOfTheLivingDead'' Ben is badly wounded by Cooper during the night and as a last resort locks himself in the basement against the zombie horde. When we last see him, the door seems to be holding, but Ben has no supplies and his wound is worsening. When Patricia returns the next day with a group of locals, they eventually manage to open the door to the basement, and encounter the now zombified Ben.
* In ''Film/{{Pumpkinhead}}'', a man summons a spirit of vengeance (the titular Pumpkinhead) after his son is accidentally killed by reckless teenagers. Realizing how screwed up things have become, he tries to stop Pumpkinhead; to do so, he himself must die. At the end of the film the man has to become the next Pumpkinhead.
* All the alternative endings of ''Film/TheRuins'' show the FinalGirl succumbing to the evil [[spoiler:plant spores]] in some way, while it is suggested in the theatrical one.
* Creator/DavidCronenberg's ''Film/{{Shivers}}''...and then Dr. Saint-Luke was Infected. Ironically, David Cronenberg considers this a ''happy'' ending, as he's said the Infected are happy and free of their inhibitions, and at the end they're about to [[spoiler: share their newfound freedom [[UtopiaJustifiesTheMeans with the whole world]]]].
* ''Film/{{Skyline}}'' has [[spoiler:Jarrod's brain installed into an alien, only for his HeroicWillpower to grant him control over that alien instead of just becoming its CPU]].
* ''Franchise/StarWars'': And then the Jedi Anakin Skywalker became the evil Sith Lord, Darth Vader.
* At the ending of ''Film/TheThing1982'', it appears as though the Thing was killed in an explosion. However, Mac and Childs are still around, and it's not revealed whether or not they had been infected, leaving them to wait and see what happens. The most optimistic reading possible is that they both freeze to death.
* In ''{{Timecrimes}}'', Hector gets stabbed in the arm and chased through the forest by a man in a black coat with his head covered by bandages. Then he travels backwards in time an hour, cuts his head, and begins bandaging the cut. Realizing that he's in a StableTimeLoop, Hector completely wraps his head in bandages, then takes a pair of scissors and attacks his past self, deliberately causing the series of events that led to his climbing into the time machine an hour ago.
* Near the end of ''Film/UndeadOrAlive'' Elmer makes the mistake of punching an infectious zombie in the mouth, and almost immediately realizes that he is beginning to turn. While he uses the last few moments before the hunger overwhelms him to attempt to make a Heroic Sacrifice, he succumbs in the end, infecting one companion and convincing him to help devour another.
* At the end of ''Vampire Assassin'', the [[spoiler:protagonist becomes a vampire]].
* In ''Film/VanHelsing'', the Live Action movie, Van Helsing becomes a werewolf to battle Dracula because apparently vampires are weak against werewolves.
* ''Film/TheWolfman2010'' ends with Lawrence dead, but only after having [[TheVirus bitten Aberline]], whose horrorstruck OhCrap look suggests he's just realized the implications.
* A variant occurs in ''Film/{{Underworld}}''. [[spoiler: Decoy BigBad Lucien]] is attempting to turn Michael Corvin into a Vampire/Werewolf hybrid as a means of ending the war between the species while Selene investigates the Lycanths' interest in him and attempts to protect him. He nonetheless succeeds in turning Michael into a werewolf as the first step in the process, and when Selene's Vampire Dad Viktor is awakened and learns of this, he is determined to kill Michael and prevent it. Selene instead completes the process herself to stop Viktor and Michael becomes a hybrid.
* ''Film/{{Carved}}'' has the main character being possessed and becoming the new Kuchisake-onna/Slit-Mouthed Woman.
* In ''Film/TheMidnightMeatTrain'', Leon becomes the new Butcher at the end after he defeats his predecessor.
* Ripley in ''Film/AlienResurrection''. Due to genetic mixing Ripley 8 has inherited a lot of Alien characteristics, and sympathizes with them to a certain extent. This version of Ripley is technically a different character, but the irony has to be appreciated of Ripley becoming so much like the Aliens after she fought them for so long. When she's being brought to the Queen by one of the Aliens after she's captured, she actually hugs the thing ''as if she's finally come home''.
** [[spoiler:Fifield]] in ''Film/{{Prometheus}}''. [[spoiler:The black liquid transforms him into an incredibly strong creature that was nigh-invincible. He wasn't exactly a classic zombie, but since he seems to be pretty much utterly under the control of the infection this still counts]].
* An alternate ending in ''[[Film/FromDuskTillDawn From Dusk Till Dawn 3: The Hangman's Daughter]]'' show one of the protagonists, Creator/AmbroseBierce, telling his tale to a bar patron. When the man doesn't believe his story, Ambrose offers proof...by promptly pulling the man's heart out. The final shot is his eyes changing to a gold color, him gaining fangs and growling inhumanly before he eats the heart.
* ''Film/DistrictNine'' shows in an epilogue that Wikus has fully become a Prawn.
* The [[MonsterMash requisite werewolf]] wrestler in ''Film/MonsterBrawl'' became one after he took vengeance on one who killed his girlfriend, getting infected in the process.
* ''Film/{{Nightbreed}}'': Villainous variation. The hateful serial killer Dr. Decker, who despises everything that isn't him and regarded the Nightbreed as vermin that he wanted to exterminate, becomes a Nightbreed himself in the SequelHook at the end when the priest revives him. Now he's an undead, superpowered serial killer more dangerous than ever.
* At the end of ''Devil's Pass'', the Final Girl and Final Guy try fleeing into the Stargate to escape the creatures. But it turns out the Stargate is the source of the creatures because traveling through it turns you into one. Whoops!
[[/folder]]

[[folder:Literature]]
* ''AbrahamLincolnVampireHunter'' has the twist ending of... well, guess.
* ''AnimalFarm'' ends with [[spoiler:the pigs coming to resemble human farmers so closely that the other animals find it hard to tell them apart from humans--they even begin to walk on two legs, wear human clothes, and carry whips. This is a rather {{Anvilicious}} commentary on how [[FullCircleRevolution many revolutionary leaders become as corrupt and oppressive as the leaders they overthrew, if not more so.]]]]
* In P C Hodgell's ''Literature/ChroniclesOfTheKencyrath'' series, a singer named Ashe is bitten by haunts (ghouls with an infectious bite) during a battle early in the second book but hides her wounds. By the time of the final battle in the book, she is technically dead (but hiding it well and fully in control of herself), and plays a key part in the main protagonist's (Jaime's) survival: Ashe guards Jaime's back while taking wounds that would have killed a living Kencyr many times over. Ashe's motives are unclear but seemed to include dispassionate curiosity.
* ''Literature/{{Goosebumps}}'':
** In ''[[OurWerewolvesAreDifferent The Werewolf of Fever Swamp]]'', [[spoiler: the werewolf bites the hero, passing the curse onto him.]]
** ''Calling All Creeps''. Some reptilian monsters that can turn into human form come to think that the protagonist, a boy bullied by most of his school, is one of them. They have plotted how to transform everyone in school, and then on town, country and world, in Creeps like them and the hero is trying to stop them from feeding everyone the transforming goo. [[spoiler: In the last moment, when he is mocked one more time while trying to stop everyone from eating goo-filled muffins, he is told that he will be the ruler of all Creeps and no longer a target for bullies. The protagonist does a quick FaceHeelTurn, treats everyone to eat the muffins, and eats one himself, becoming the real Creep leader.]]
* In ''Literature/{{Hater}}'' by David Moody, the main character [[spoiler: becomes a Hater about three-quarters of the way into the book, after a prolonged struggle to defend himself and his family from them.]]
* In ''JohnDiesAtTheEnd'', it is revealed in the penultimate chapters of the book that somewhere along the course of the story, [[spoiler: Dave has been replaced with a "monster" version of himself]], becoming the very doppelganger that part of the story's arc has revolved around. Considering the character John [[spoiler: neither dies nor suffers Dave's fate of becoming that which they fought]], this could be a subversion. Especially likely considering the writer is Cracked Editor [[OneofUs David Wong]].
* In ''{{Necroscope}}'', vampirisation happens to the good guys every now and again. Eventually, [[spoiler:Harry Keogh is subject to this as well]].
* In the ''{{Newsflesh}}'' book ''Feed'', [[spoiler: Georgia, the narrator, gets shot up with Kellis-Amberlee virus and turns into a zombie and has to be killed by her brother.]]
* At the end of ''TheSecretsOfTheImmortalNicholasFlamel'' series, [[spoiler: Josh becomes Marethyu, better known as TheGrimReaper.]]
* ''ShinigamiGodOfDeath'' by Django Wexler has the younger of two sisters [[spoiler: bring her mother and her older sister back to life, using the same method the Lightbringer did. Unfortunately, this causes her to be imprisoned as he was.]]
* ''Waves Put Out The Wind'' by the brothers Strugazkiys has a commission that ensures that no SufficientlyAdvancedAliens can improve human history unnoticed. One of the employees gets some hidden superpowers activated while investigating a superhuman organization. [[spoiler: He remains well-intentioned but becomes too inhuman, gradually losing his contact with humanity. All "ludens" (anagram of inhuman in Russian and a reference to "Homo Ludens" - human that plays) have this fate. ]]
* Literature/GalaxyOfFear: City of the Dead has Zak Arranda caught up in the experiments of Doctor Evazam, who had noticed that recently dead bodies on Necropolis sometimes became [[OurZombiesAreDifferent mindless zombies]] after being exposed to boneworms. Evazam found out how to replicate their results, that these zombies followed his orders, and altered results so that the undead might retain some mind and memories. He used mindless zombies to kidnap one of Zak's friends, killed the boy and used that version on him, then had the zombie child help him kidnap Zak, doused him with the formula, and had him BuriedAlive. Later Zak was dug up and found that his friend had enough mind left to help when Zak pleaded with him, but later returned to being a normal corpse along with the other undead after being exposed to an anti-formula. Zak himself was not exposed, and although he resisted any suggestion that he had died during his ordeal and was now a zombie, he was shown spasming uncontrollably as they sometimes did.
* ''Literature/TheShadowOverInnsmouth'' ends with the results of the narrator's genealogical tour of New England. [[spoiler: He has ancestors from Innsmouth... from the Marsh family, to be exact. Which means he's a Deep One hybrid himself.]]
* ''Literature/{{Twilight}}''. Happens to nearly all of the main characters, though for most it was an EmergencyTransformation.
* The hunters of the Immortals in Terry Maggert's [[http://www.amazon.com/Forest-Bull-Fearless-Book-ebook/dp/B00EWCWZEG Fearless series]] become progressively more inhuman the more immortals they kill.
[[/folder]]

[[folder:Live Action TV]]
* ''Series/{{Angel}}'': Gunn is transformed into a vampire sometime between the TV series finale and ''After the Fall''. A ResetButtonEnding restores Gunn to human form - but he retains the memories of the murders he committed as a vampire.
* ''Series/TwinPeaks'' ends on a CliffHanger as Dale Cooper becomes possessed by the very entity he's been fighting throughout the course of the series. Could've been resolved in a third season but... ExecutiveMeddling.
* ''Series/AreYouAfraidOfTheDark'': In "The Tale of the Chameleons", Janice gets turned into a chameleon and drowned in a well, and her EvilTwin plans to do the same to her friend and the rest of her family.
* The ''Series/DoctorWho'' episode "Survival" has this as the major plotpoint.
** Also in "Asylum of the Daleks" where [[spoiler: Oswin was a Dalek the whole time. She was only dreaming she was a human.]]
* ''Series/{{Dollhouse}}'' Season 2. [[spoiler: Paul Ballard spends season one and most of season two trying to break down the dollhouse and free the dolls. But he is then sent into a brain-scarred coma by Alpha and is only saved when Topher rewires his brain with the active protocol and rewrites some part of his brain to work in place of the scarred tissue, effectively turning him into a doll.]]
* Many of the characters in the live action adaption of ''{{Goosebumps}}''. Most episodes follow the books to the letter. But a noticeable deviation is ''Vampire's Breath'': in the book the whole adventure was played straight in which the protagonists spend the whole episode trying to avoid getting bitten and eventually succeed (though one of them takes a substance meant for werewolves). In the TV version however, [[spoiler: the two find out that their whole family are vampires (the one chasing them was actually a relative) and that the siblings have now come of age where their fangs have grown in.]]
* In ''Series/KamenRiderDecade'', this happens to [[spoiler:AU![[Series/KamenRiderHibiki Hibiki]].]] In fact, this trope is a common theme throughout the franchise, although the difference is that they ''were'' the "zombies" in the first place or take the source of their power from the very monsters they fight.
** For a straight example, the earlier titular ''Series/KamenRiderBlade'', [[spoiler: by virtue of overtaxing his use of his [[DangerousForbiddenTechnique King Form]] (which uses the powers of all the [[MonsterOfTheWeek Undead]] he has captured), is already slowly becoming a Joker-type Undead himself.]] In order to prevent [[TheEndOfTheWorldAsWeKnowIt the impending apocalypse a single remaining Joker Undead would cause]], [[spoiler: he chose to [[HeroicSacrifice go through it and transform into an Undead himself]], putting the apocalypse on deadlock.]]
** Also happens in ''Series/KamenRiderOOO'': [[spoiler: Eiji is slowly becoming a Greeed due to the purple Core Medals entering his body. He eventually transforms into a second Dinosaur Greeed after [[BigBad Dr. Maki]] inserts two more purple Medals into him.]]
* How much does Joe of ''TheLostRoom'' love his daughter? Well, after spending all the series [[GottaCatchEmAll trying to find the Object]] to rescue her from a NegativeSpaceWedgie, he [[spoiler: becomes an Object to save her. That's right, he gives up being a human and becomes a sapient, mobile, indestructible and unaging ''thing.'' This is presented as a good thing however, despite the former Object/person/Occupant pretty much hating his existence.]]
* The end of ''Series/{{Supernatural}}'' season three seems to apply to Dean [[spoiler: once he finds out that demons are ex-humans. He also gets tortured enough in hell so that he finally breaks and starts torturing others and enjoying it because it isn't him.]].
** By the end of season four, [[spoiler: this trope applies to Sam. No, Sam,]] you are the demons.
** Used again with [[spoiler: Gordon, who started out as a vampire hunter and is eventually captured and turned by a group of them.]]
** [[spoiler: Bobby Singer has spent decades hunting but is killed in Season 7.]] He comes back as a ghost with the intention of helping Sam and Dean but his desire to get even with the creature that killed him starts to turn him into a full blown poltergeist to the point that he begs them to put him down for good before he kills someone
** Anna, a fallen angel, is against a lot of heaven's more deranged decisions (mostly the ones about armageddon), but after being captured and tortured by them she decides that killing Sam as an infant is the best solution
** Castiel suffers from this in season 8 [[spoiler: after being brainwashed by Naomi to become a mindless solider for her, the very thing he started civil war over.]] He gets better.
** The cliffhanger for season 9 has [[spoiler: Dean getting killed and brought back as a demon.]]
* Tara from ''Series/TrueBlood''. She hates vampires after being kidnapped and raped by one in the third season, and spends the fourth season helping the BigBad try to wipe them out. She is killed when she takes a bullet to the head for Sookie, and the fifth season begins with Lafayette and Sookie begging Pam to turn her. It works, and Tara takes the news about as well as you would expect.
* In the 1986 ''[[Series/TheTwilightZone Twilight Zone]]'' episode "Monsters!", the presence of a (kind-natured) vampire in their neighborhood causes every normal person in suburbia to temporarily mutate into a pack of gruesome monsters that kill the vampire - afterwards, they're horrified at the murder, never realizing that they were the monsters.
* ''Series/TheVampireDiaries'' does this multiple times:
** First with Caroline's dad who chooses not to complete the transformations.
** Later with Alaric who is turned into an Original Vampire just to become the world's greatest vampire hunter.
** Finally, the Season 3 finale brings the comparisons between Elena and Katherine to their logical conclusion and ends with Elena turning into a vampire.
* The season 2 finale of ''Series/{{Grimm}}'' ends with [[TheHero Nick]] getting turned into a zombie. That said, these zombies [[TechnicallyLivingZombie aren't actually dead]], just merely infected with a poison that simulates the appearance of death, until the victim revives with a sickly pallor and [[HatePlague hyper-violent]] tendencies. Being a Grimm, he's a lot stronger than the others.
* ''Series/BuffyTheVampireSlayer''. Happens a few times:
** Angel, leading to him become HeWhoFightsMonsters once he regains his soul.
** In "Nightmares" Buffy fits this trope when she (temporarily) becomes a vampire.
** In "Phases" Oz discoveres he's a werewolf.
* ''Series/FearItself'' did this with the episode "New Year's Day". You think the female protagonist, Helen is one of the few remaining survivors after a zombie apocalypse begins, [[spoiler: only to discover at the very end that she committed suicide the previous evening and was resurrected shortly afterwards as one of the zombies]]
[[/folder]]

[[folder:Music]]
* Music/BlackSabbath's "Iron Man." Through a StableTimeLoop, a man travels to the future and witnesses TheEndOfTheWorldAsWeKnowIt at the hands of the titular villain, then travels back in time to warn people about the coming threat, but in the process is transformed into Iron Man himself.
* In the music video for Bastille's "Pompeii," the protagonist spends most of the video trying to find somebody else who hasn't succumbed to some some sort of plague that turns your eyes black. In the last moments of the video, his eyes turn black as well.
* The song "Haunted Town" by Music/{{Lordi}} starts when the singer finds himself in the middle of a ZombieApocalypse. In the end he realizes that [[TomatoInTheMirror he's actually dead himself]]:
-->I searched the old graveyard
-->for an answer
-->In the mossy headstones
-->I found my name
-->Ooh, I walk among the dead
[[/folder]]

[[folder:Mythology]]
* Used in this Nigerian folktale.
-->A hunter goes into the bush. He finds an old human skull. The hunter says: “What brought you here?” The skull answers: “Talking brought me here.” The hunter runs off. He runs to the king. He tells the king: “I found a dry human skull in the bush. It asks you how its father and mother are.” \\
\\
The king says: “Never since my mother bore me have I heard that a dead skull can speak.” The king summons the Alkali, the Saba, and the Degi and asks them if they have ever heard the like. None of the wise men has heard the like, and they decide to send guards out with the hunter into the bush to find out if his story is true and, if so, to learn the reason for it. The guards accompany the hunter into the bush with the order to kill him on the spot should he have lied. \\
\\
The guards and the hunter come to the skull. The hunter addresses the skull: “Skull, speak.” The skull is silent. The hunter asks as before: “What brought you here?” The skull does not answer. The whole day long the hunter begs the skull to speak, but it does not answer. In the evening the guards tell the hunter to make the skull speak, and when he cannot, the guards kill the hunter in accordance with the king’s command. \\
\\
When the guards are gone, the skull opens its jaws and asks the dead hunter’s head: “What brought you here?” The dead hunter’s head replies: “Talking brought me here!”
* According to Japanese mythology, killing many {{youkai}} (a thousand, according to some versions) results in their slayer being transformed into a youkai himself. Then again, anyone capable of killing 1000 demons is powerful enough to be considered a demon himself by most people, so this could just be a LampshadeHanging on that fact.
[[/folder]]

[[folder:Tabletop Games]]
* This is a quite common fate for any investigator in ''TabletopGame/CallOfCthulhu'', ranking perhaps just below "killed by horrible monster existing in fourteen dimensions at once," "lab rat or soul-in-a-jar for horrible monster," "spends remainder of his or her life eating cockroaches in a padded cell," and "gets brain stolen by horrible monster."
* The end result in ''TabletopGame/ChangelingTheLost'' for changelings whose [[SanityMeter Clarity]] gets too low and their [[PowerLevels Wyrd]] too high. They leave for Arcadia and become exactly the same as the monster who kidnapped and abused them in the first place.
** WhiteWolf in general is in love with this trope, as it is likely to come into play in both versions [[TabletopGame/VampireTheMasquerade of]] [[TabletopGame/VampireTheRequiem Vampire]] [[HunterTheReckoning and]] [[TabletopGame/HunterTheVigil Hunter]], old [[TabletopGame/WraithTheOblivion Wraith]], TabletopGame/KindredOfTheEast, and ''TabletopGame/DemonTheFallen''. It is also possible in [[TabletopGame/MageTheAscension both]] [[TabletopGame/MageTheAwakening Mages]], TabletopGame/WerewolfTheApocalypse, TabletopGame/ChangelingTheDreaming, and {{TabletopGame/Orpheus}}. The list just goes on....
* ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/{{Warhammer 40000}}'' use this trope heavily. In 40k, it is TurnedUpToEleven, where not only do you turn into a demon, but you also have a good chance of winding up causing the deaths of billions. The pen and paper RPGS DarkHeresy and RogueTrader feature extensive rules on corruption by the Ruinious Powers just to fit this trope.
** BlackCrusade takes this trope and runs with it. With trying to become a high-ranking demon a being a valid goal for the player.
* In ''TheWhisperingVault'', people who investigate the [[EldritchAbomination Unbidden]] and survive tend to be turned into [[HumanoidAbomination Stalkers]]... but given how a Stalker's entire purpose is to [[DarkIsNotEvil protect reality from Unbidden and retain most of their human personality]], this comes off more as a transhumanist reward.
* In ''TabletopGame/DungeonsAndDragons'' several undead have the create spawn ability, turning a victim into an undead (often the same kind as the killer) under their control.
[[/folder]]

[[folder:Theater]]
* Alfred, the assistant vampire hunter in ''TanzDerVampire'', becomes an undead bloodsucker himself at the end of the show. Worse, the vampire that turns him is none other than Sarah, the girl he loves and was trying to save. However, in the Musical this isn't depicted as especially bad, as due to sympathy-songs etc. the spectators are expected to have sympathy with the vampires and the only one really wanting to kill vampires was the professor.
[[/folder]]

[[folder:Video Games]]
* Literally in UndeadNightmare, a spin-off game to RedDeadRedemption. In it, a ZombieApocalypse breaks out, and John sets out to find the cause of it, if possibly a cure. [[spoiler:In the end, he discovers that the powerhungry Reyes from the original story heard of a mask hidden in an Indian burial ground that could make him invincible, but stealing it and testing it out, it instead cursed him and the rest of the land as punishment. John manages to return the mask to where it belongs and rids the world of the plague. A few months later however, Seth, a treasure hunter finds and steals the mask, starting it all over again. John by this time is dead due to the events of the original story, to which we're treated to him rising from his grave as an unintelligible zombie (though thankfully, due to some special circumstances, he also turns out to be a sentient one). The Achievement for completing the game directly quotes the TropeNamer.]]
* ''[[VideoGame/{{Boktai}} Boktai 2]]'' has Django turned into a vampire and forced to do an entire dungeon hiding from the sun, sucking blood, and turning into a mouse or bat to stay alive. He eventually get the ability to change between human and vampire at will, but the game makes it very clear that he is in constant risk of losing himself forever.
** It can happen too, as a couple of [[EasterEgg Easter Eggs]]. You can say yes to Dainn's WeCanRuleTogether offer, and you can even bite Lita and suck her blood. Both earn you a NonStandardGameOver.
* ''BlizzardEntertainment'' seems to love the trope.
** At the end of ''VideoGame/{{Diablo}}'', the hero defeats the titular boss and jams its [[SealedEvilInACan soulstone]] in his/her own forehead to contain it. This results in [[spoiler:the hero becoming the new BigBad in ''VideoGame/DiabloII''.]] This was later [[RetCon retconned]] in ''Diablo II'' by saying that said hero was more or less [[MindRape mindraped]] into doing so.
** It's uncertain how long [[HeroOfAnotherStory Tal Rasha]] held out containing Baal this way, but considering the ''Diablo II'' expansion, it's probably safe to say that anyone who fights demons succumbs to this in some degree.
*** And again in ''VideoGame/DiabloIII''. Leah, niece of Deckard Cain starts off as a genuinely good character. Then she finds out that [[spoiler: her Mom is an evil witch, and her dad is the wanderer from ''Diablo II''. She becomes corrupted by the soulstone after capturing a few more demons in it (thus becoming an even more powerful version of) Diablo herself.]]
** In ''VideoGame/{{Starcraft}}'', Kerrigan fights the Zerg during the Terran campaign but becomes one during the Zerg campaign. [[spoiler:[[DarkActionGirl She]] [[VideoGame/StarcraftII gets]] better... and then she ''re-infests'' herself for the second time.]]
** Similarly, Arthas and Illidan in ''VideoGame/{{Warcraft}} III''. Note that in the cases of Kerrigan and Arthas, the trope is in that they become leaders of the factions that they opposed, not those that they first joined.
*** Sylvannas fights Arthas' undead right up to the point where she was killed and resurrected as a banshee.
** A playable example: No, warlock. [[http://www.wowhead.com/spell=59672 You are the demons.]]
* In the end of ''Videogame/AloneInTheDark2008'', [[MortonsFork either Carnby or Sarah]] becomes a demon of Lucifer.
* At the end of ''Apocalypse'', Creator/BruceWillis's character is [[DemonicPossession demonically possessed]].
* Halfway through the FirstPersonShooter ''Area51'', your character gets mutated; this is also a case of PhlebotinumRebel.
** The other ''Area51'' (the LightGunGame) has this on the GameOver screen, which also happens to be the Game Clear screen. Strangely enough, you ''can'' do this early enough in the game by shooting three STARR members (the friendlies) and no one else, which covers the game screen in trippy vision and replaces your bullets with alien darts.
* Both ''VideoGame/BatenKaitos'' games use this, albeit in very different ways.
* ''[[VideoGame/DarkCastle Beyond Dark Castle]]'': And then Prince Duncan was the BlackKnight.
* The worse endings of ''VideoGame/BioShock1'' have you becoming just as much of a monster as Andrew Ryan [[spoiler:and Frank Fontaine.]]
** Also done to a degree earlier. In order to complete the game it's necessary to [[spoiler:be converted into a Big Daddy, the most dangerous and iconic enemies of Rapture]].
* ''VideoGame/BioShockInfinite'' also gets in on the action, revealing that [[spoiler:Booker and Comstock are the same person, only Booker in this universe did not run away from his baptism, and the Booker you play sold his infant daughter, Anna, to "wipe away the debt".]]
* This is the bad ending of ''VideoGame/TheBreach''. [[spoiler:After the most recent update, it's the ''only'' ending.]]
* In ''VideoGame/{{Castlevania 64}}'s'' DownerEnding, you get this on two levels; a side character, Vincent the vampire killer, becomes a vampire. Also, Carrie agrees to marry Malus (Dracula), to which he ominously notes that they have "a binding contract".
** VideoGame/CastlevaniaLordsOfShadow: [[spoiler: "EU SUNT DRACUL (I AM DRACUL)!"]]
** If you unlock the true ending path of ''[[VideoGame/CastlevaniaChroniclesOfSorrow Aria of Sorrow]]'', then upon defeating [[spoiler:Graham Jones]], who has declared himself Dracula's reincarnation, [[spoiler:Soma himself]] is revealed to ''actually'' be the reincarnation of Dracula. And if you get the bad ending, by losing to the TrueFinalBoss, then he quite literally becomes the "second coming" of Dracula, in mind as well as ability.
* In ''[[VideoGame/ChzoMythos 6 Days a Sacrifice]]'', the main character, Theo [=DaCabe=], [[spoiler: is turned into the mindless servant 'The New Prince' by Chzo after the old servant Cabadath tries to betray him, because Cabadath didn't want to be replaced.]]
* The ending of the original ''VideoGame/{{Condemned}}'' seems to imply that main character Ethan Thomas has become one of the demonic freaks causing all the chaos in the game. The sequel josses this, as Ethans winds up as a burned out alcoholic bum, [[spoiler: and the demonic freaks [[VoodooShark are really just an ancient mystical cult]].]]
** Even then, it still could be a case of this trope; in both games, the primary enemies are pyschopathically violent homeless people, driven mad by the real villains. In ''Bloodshot'', he's suffered substantial SanitySlippage and starts off pretty much only slightly less unhinged than the psychopaths he fights.
* ''VideoGame/DeadSpaceExtraction'': [[spoiler: In the first chapter, you play as one of the soon-to-be necromorphs and unknowingly kill all your comrades.]]
** [[spoiler: Then at the end of the game one of the main characters turns into a necromorph too. Though considering the later DLC for part 2. It was revealed as being a dream.]]
* ''VideoGame/{{Disgaea 2|Cursed Memories}}'s'' [[MultipleEndings worst ending]] features this. ''In spades''. If Adell has met the required conditions, [[spoiler:Rozalin, the ''real'' Overlord Zenon, will inform you that you too are her enemy. If you are victorious, Zenon's evil will consume Adell's soul. His first act as the new God Of All Overlords? To devour his younger brother and sister, bones and all, ALIVE.]] Cue crunching sounds.
* In VideoGame/DungeonsOfDredmor, the first 3 levels of Demonologist give you resistance to [[LightIsNotGood Righteous damage]], and useful powers when fighting demons. Any further than that, and you lose all that resistance in exchange for more versatile moves. What's the name of the penultimate level, giving you a chance to transform in to a literal combat monster? [[ShoutOut 'No, you are the demons']].
* In ''VideoGame/DivinityIITheDragonKnightSaga'', the player starts off as a Dragon-slayer. After abour one hour of gameplay, he is turned into a dragon-knight.
* The ''good'' ending of ''{{Eversion}}'' turns your character into [[spoiler:an EldritchAbomination just like the princess you're out to save.]] The bad ending has [[spoiler:you resisting this and getting eaten by the princess.]]
** Unless, of course, [[spoiler:[[TomatoSurprise you already were an eldritch abomination all along.]]]]
* ''VideoGame/EternalDarkness'': Anthony's chapter casts the hero as a Frankish messanger who intercepts a message intended to curse Charlemagne by exhausting the curse on himself first; his chapter is devoted to racing to defend Charlemagne while slowing succumbing to the corrosive curse [[spoiler:though his efforts are futile]]. In Paul Luther's chapter later on, Anthony is encountered again, tragically having been turned into a zombie of Augustus Pious's dark god.
* The ending of ''VideoGame/{{Fable}}: The Lost Chapters'' gives you the option of putting on Jack's mask, becoming his new host.
* In ''VideoGame/GemCraft'' Chapter 0, the force you're trying to claim takes over, but it's a prequel and the truth was fairly obvious based on the events of the first game.
* Happens at the end of ''VideoGame/GodOfWar'', as amusingly portrayed in [[http://coelasquid.deviantart.com/art/God-of-War-Abridged-137533787?offset=20 this comic strip.]]
* In the bad endings of ''The Videogame/HouseOfTheDead'', [[spoiler: Goldman or a character close to the protagonists]] turn into a zombie.
* Happens in one of ''Kichikou Rance'''s endings, where Rance, depressed either for Sill's death or absence (if the player is taking too long in rescuing her) finally gives in to Satera's suggestions of becoming the Demon King, committing immediately after a MoralEventHorizon [[spoiler:cruelly killing poor Miki, who, crushed by the betrayal, lets herself be hacked during hours, since she's ''that'' tough.]] Then he becomes a powerful Demon King, who crushes without trouble the human nations, with Satera at his side.
* In the [[MultipleEndings bad ending]] of the first ''VideoGame/KidIcarus'' game, Pit is turned into a monster. Oddly, it's ''[[UngratefulBastard Palutena]]'' that does it to him. Maybe this is really supposed to be the joke ending?
* In ''KingdomHearts'', Sora [[spoiler:[[HeroicSacrifice impales himself with Riku's Dark Keyblade in order to free Kairi's heart]], releasing her from her catatonic state. In the process, he becomes a Heartless ''and'' creates two Nobodies: Roxas (himself) and Naminé (Kairi). Of course, it doesn't stick, Kairi leads him back to the light, but in ''VideoGame/KingdomHeartsII'', you will occasionally turn into Anti-Sora when activating a Drive Form.]]
** ''[[VideoGame/KingdomHeartsBirthBySleep Birth by Sleep]]'': [[spoiler:By continuing to use the darkness, Terra's heart is weakened. The straw that broke the camel's back was Master Xehanort orchestrating Terra's [[RageAgainstTheMentor emotionally-supercharged duel with Master Eraqus]] and then [[ShootTheDog killing a weary Eraqus just as he and Terra were calming down from and remorsing over their fight]]. When Terra gives into his [[UnstoppableRage rage]], unleashing the full extent of his inner darkness, Xehanort uses this as the perfect opportunity to [[GrandTheftMe take over Terra's body]]. Thus, Terra has become the one thing he's hated the most: ''Xehanort himself''. [[TragicHero Luckily for him]], [[TheWoobie and several others across the series' timeline, including his close friends Ventus and Aqua]], [[MessianicArchetype Sora]] [[EarnYourHappyEnding is going to earn a happy ending for them]]]].
* This happens in ''KnightsOfTheOldRepublic'', after TheReveal; always for Bastila and optionally for the player.
* In ''VideoGame/LaPucelle'', if you defeat certain powerful enemies in the Dark World/Netherworld (which requires a lot of LevelGrinding), a band of demons will appear and declare Prier their new ruler... which Prier [[SubvertedTrope rejects out of annoyance]] after being teased by her teammates, and [[GameplayAndStorySegregation the game continues anyway, ignoring this interruption]]. However, if she continues on past that, becoming even stronger, she triggers a NonStandardGameOver as the demons make her their new ruler for good and her friends abandon her. Prier being a demon queen is ''the {{canon}} ending'', as she puts in several appearances in the ''Franchise/{{Disgaea}}'' series as "Demon Overlord Prier," a powerful optional character, as a half-demon with wings and a horn.
** Curiously, the plot [[GameplayAndStorySegregation still ignores this.]] Until the UpdatedRerelease for the PSP, that is.
* In ''LegacyOfKain: Soul Reaver 2'', it turns out that [[spoiler:the Soul Reaver is in fact Raziel's soul, which was absorbed into the original blood stealing "Reaver" and driven insane from being trapped for hundreds of years.]] And that he is doomed to fulfill this fate over and over again [[spoiler:at least until Kain creates a paradox and saves him... until ''Defiance'' when Raziel willingly becomes the Soul Reaver, purified of any corrupting influence.]] In true mind-breaking ''LegacyOfKain'' style, this is ''also'' TomatoInTheMirror. There's a TomatoInTheMirror ''because'' John became a zombie at the end.
* In Oersted's chapter of ''LiveALive'', he spends most of the chapter trying to vanquish the Demon King. Then, [[spoiler:after everyone around him either dies, betrays him, or turns against him due to a ''really big'' misunderstanding,]] he decides to ''become'' the Demon King, thus setting the stage for the rest of the game.
* The HiddenObjectGame ''Love and Death: Bitten'' features Daemon and Victoria, the former a vampire and the latter a human trying to help him regains his humanity. At the end of the quest [[spoiler: Their roles are reversed. Daemon is turned back into a human, but in trying to beat the vampire queen that turned him. Victoria is captured and bitten, becoming a vampire]].
* At the end of the second act of ''VideoGame/{{Marathon}}: RED'' (a GameMod), the hero is mutated by TheVirus, and his former allies turn against him for a stage, but he turns PhlebotinumRebel.
** At the end of ''EVIL'', the Cyborg's [[BrainUploading mind is uploaded]] to the D'ricta's core and made into an AI, [[AIIsACrapshoot which proceeds to go rampant]].
* Present in [[MultipleEndings one of]] ''Videogame/MassEffect3'''s endings. [[spoiler: Shepard, the protagonist, [[HijackingCthulhu takes over the Reapers]], effectively becoming their [[AGodAmI unified intelligence.]]]] How [[spoiler:s/he handles it]] depends on the player's KarmaMeter-if you play as a Paragon, [[spoiler:s/he focuses on protecting the galaxy]], but if you're Renegade, [[spoiler: s/he places more emphasis on eliminating potential troublemakers.]]
** Also something that happens to a lot of people trying to research Reaper tech... like the entirety of Cerberus.
* Also from Bioware, ''VideoGame/DragonAgeOrigins'', in which Grey Wardens become immune to the Darkspawn taint by drinking a vial of their blood, enabling them to sense when Darkspawn are near and not fall victim to the corruption Darkspawn spread everywhere they go. [[spoiler:Then it turns out this only delays the corruption, and every Warden will eventually succumb to it and become a ghoul.]]
* Happens in ''MetalSlug 2/X'' and ''3'', with [=MS2/X=] setting the players against mummies, and [=MS3=] being the literal trope as zombie enemies can make you one of their own (though not without benefits). [[spoiler:The clones of your abducted comrade? They join in on the fun, too!]]
* In the NonstandardGameOver of ''VideoGame/MetroidPrime 3'', Samus is "terminally corrupted" and turns into Dark Samus.
* In ''VideoGame/NetHack'', the [[InvoluntaryTransformation polymorph effect]] can turn the player into almost any monster. Additionally, there's the [[spoiler:Helm of Opposite Alignment, a helmet that switches your alignment to the opposite of your own if you're chaotic or lawful, and randomly to one or the other if you're neutral.]] To make it even worse, [[ClingyCostume you can't take it off]].
* In the escape-the-room game ''[[http://www.freewebarcade.com/game/poco-escape/ Poco Escape]]'', [[spoiler: you wake up locked in a room that's sparse except for a few pictures of adorable little bears, which are naturally slightly creepy considering the circumstances. The ending heavily implies that you are actually the girl's teddy bear.]]
* In ''VideoGame/{{Portal 2}}'', you spend the first half of the game with a robotic sphere named Wheatley trying to defeat [=GLaDOS=]. [[spoiler: Guess what happens to Wheatley?]]
* In ''VideoGame/PrinceOfPersiaWarriorWithin'', when the Prince puts on the mask, he finds himself transformed into the Sand Wraith. This makes him not only a monster but a doomed monster, as he saw the Dahaka kill the Sand Wraith in the past. Fortunately, he is ultimately able to ScrewDestiny and return to his normal self.
* Played straight in ''VideoGame/PrinceOfPersiaTheTwoThrones'', where the prince is partially turned into a sand monster, complete with HeroicWillpower and a light sprinkling with a GollumMadeMeDoIt-voice, though that seems to be there more to be defied than blamed.
* Happens in ''VideoGame/{{Prototype}}'' to several characters. [[spoiler: Alex]]: "I am the virus!"
* In ''VideoGame/QuakeIV'', at a particular point that marks roughly the midpoint of the game, the protagonist is converted into a Strogg in all but allegiance. Were it not for a very well timed raid by the good guys, our hero would have crossed the point of no return, as he was almost the entire way through the [[PainfulTransformation conversion process]] by that point. He then became a PhlebotinumRebel. [[http://www.youtube.com/watch?v=3clVvh5gbGE&feature=related Wanna see?]]
* The Bydo ''love'' pulling this on humanity's heroes in the ''{{R-Type}}'' series.
** It first happens in ''R-Type Delta'', if the player is piloting the R-13 Cerebrus--that particular fighter proves incapable of escaping the final level, and the Bydo exact revenge by converting the ship and its pilot into a tree-like Bydo.
** Then there's ''R-Type FINAL'', in which one of the MultipleEndings leads to the player getting converted into a hybrid Bydo/human/R9-Series...[[TwoBeingsOneBody thing]]...and is sent back to the ''first level of the game,'' fighting both the Bydo as well as its former comrades. (It's worth noting that at the start of the game, you can ''see'' your future Bydo self [[StableTimeLoop fly by at the very start of the level]]!)
** ''R-Type Command'' also pulls this ''on an entire human fleet'' at the end of the Human campaign--in fact, the player's character in the subsequent Bydo campaign is the former human commander. In both the case of ''FINAL'' and ''Command'', the player's characters ''have no idea that they're no longer human'' and can't understand why Earth's forces are out to get them.
* In the end of ''VideoGame/{{Resistance}} 2'', [[spoiler:Nathan Hale fully mutates into a chimera.]]
* [[http://www.youtube.com/watch?v=LYNtx8E-vQE&fmt=18 The ending]] of the incredibly obscure computer game ''THE SCREAMER''. (Yes, it really is in all caps like that.)
* ''VideoGame/ShadowOfTheColossus'' has Wander gradually [[TheCorruption becoming less human]], and ends with Wander becoming a new version of Dormin's body ([[spoiler:which is what the Colossi originally are]]) himself. It fails, and he reverts to human form, but [[CameBackWrong as a newborn with demon characteristics]]. It's heavily implied that he becomes the ancestor of the horned boys in ''VideoGame/{{ICO}}'' this way.
* In the ''Possessed'' ending of ''SilentHill3'' [[spoiler:Heather becomes demon-possessed, and kills Douglas.]]
** SilentHill3 uses this trope earlier, when Vincent [[spoiler: throws doubt on whether or not Heather has actually been fighting monsters or not by mockingly saying "They look like MONSTERS to you?". Some interpret that to mean Heather has been killing people, not monsters, making ''her'' the possessed demon/mass murderer/bad guy. However, it's just as likely he's referencing the fact that many of the demons you encounter are actually considered angels in the religion of the Order.]] This is a fairly common theme in Franchise/SilentHill, with certain hints here and there suggesting that [[spoiler: you may be hallucinating everything on a murder spree, such as the inclusion of police tape in an area where you had previously fought and killed monsters]].
** In the [[MultipleEndings worst ending]] of ''SilentHillHomecoming'', Alex becomes a Pyramid Head.
** In ''SilentHillDownpour'', [[spoiler:Murphy becomes the Bogeyman for the final fight. It's not permanent, though, assuming you choose to spare Anne. This may or may not be an example of this trope though, as the game never makes it clear if you actually have become a monster or if this is simply how Anne sees you because of her father's death.]]
* Played for laughs in the HiddenObjectGame ''Sinister City''. In the end, [[spoiler:Count Orlok becomes the star of a movie in which he plays a vampire. Scenes from the film shoot are shown during the game's credits. John, the protagonist, plays a victim of the vampire in one shot with Orlok ready to bite him. Orlok bites him for real and the director calls for an ambulance. The last shot is John as a vampire.]]
* In StreetsOfRage, the player is one of three ex-police officers finding themselves duty-bound to stop the assorted crimes of [[LetXBeTheUnknown Mr. X]], a powerful crime kingpin. In the final level, Mr. X offers to make you and your co-op partner into his right-hand men. If one player accepts and one refuses, Mr. X sits back and watches while you and your former partner solve the disagreement [[ViolenceReallyIsTheAnswer the only way they can.]] If the "heroic" player loses the fight, the remaining player goes on to fight Mr. X, and if successful...[[http://i29.photobucket.com/albums/c269/StormEagle14963/streetsofrage_screen6.png No, Axel, You Are The Crime Lord.]]
** Possible again in the fan remake for any character, including [[spoiler: Mr. Freakin' X. Paradox anyone?]]
* In the end of ''VideoGame/SuperPaperMario'', Luigi ends up as part of Dimentio's plan and pilots a giant robot before being cured by Mario. It ''was'' implied something might happen to Luigi a few minutes before that, though.
* ''VideoGame/{{Team Fortress 2}}'s'' auto-balance mechanic tends to do this with frequently frustrating timing. A player can lose due to having personally destroyed the only defense guarding against said failure immediately prior to being switched to the opposite team.
* Happens in the end of ''VideoGame/ThroneOfDarkness'', to TheMagnificentSevenSamurai. After defeating the Dark Warlord, their feudal lord reveals that [[spoiler: he only wanted you to retrieve the [[AppliedPhlebotinum immortality potion]].]] [[spoiler: He then drinks the potion, transforms into the next dark warlord, kills his own servants (the player's part) and brings them back as zombies]].
* [[TouhouProject Touhou's]] [[{{Miko}} Kochiya Sanae]] recieves a warning that [[HeWhoFightsMonsters she who hunts youkai]] may become one, as well. In her profile, it's mentioned that Alice was a human who became a youkai to pursue power. In supplementary materials, Marisa is confirmed to experiment with methods of gaining immortality, but in one game she refuses to eat an immortal person's liver to get it. Reimu also has that option, and doesn't balk at the ''method'' so much as the idea of becoming anything remotely inhuman.
** Marisa is a curious exception to magicians in general; it's stated AllThereInTheManual that becoming a Youkai Magician is a natural progression of studying magic. Marisa has made neutral comments towards immortality; and AlternativeCharacterInterpretation goes both ways towards whether she's heading towards becoming youkai; or if she'd want to.
** Hijiri Byakuren was a human Buddhist monk who used dark magic to retain her beauty, making her the kind of ''{{youkai}}'' called a Magician. Fearing the loss of her power if it became completely rejected (denied) by humanity, she decided to privately dedicate her efforts to the prosperity and survival of ''youkai''. Publically, she acted like a trustworthy ''youkai'' exterminator to the humans, though she actually used her position to keep the ''youkai'' from significant harm. Her efforts shifted slowly more towards overt assistance to ''youkai'', were eventually exposed to the humans, and she was declared a "demon in human form," and was sealed in the demon world of Makai. So, in a round-about way ...
* In the final installment of ''VideoGame/{{Xenosaga}}'', one of the many antagonists, Dmitri Yuriev, tries to conquer his fear of God by becoming a god himself [[spoiler: using the Zohar and Abel inside Omega Res Novae]]. It works, of course[[spoiler:, but then his clone/son who is supposed to be dead, Albedo, pops up and takes it all away. Makes one wonder...]]
* The end of ''VideoGame/ZombieDriver'' has [[spoiler:the protagonist that ran over hundreds of zombie hordes turn into a zombie from an infected bite he got much earlier in the game.]]
* Used as a ''game mechanic'' in ''VideoGame/ZombiU.'' You technically only have one life, and when killed, your character then becomes a zombie, and all of your inventory is left with them. If you die, you take control of a different survivor who has to follow the same VoiceWithAnInternetConnection to survive, but also having to track down your predecessor, defeat them, and getting back your inventory. If you have an internet connection, you may also come across other players' fallen survivors.
* If you take a long time to feed on delicious meat, the Demon Virus in ''DigitalDevilSaga'' is going to take hold on your psyche and ShapeshifterModeLock you in demon form. At that point, the kindest thing that can be done for you is to bash your brains in before you start mindlessly eating others. In a misguided effort to do good, two named characters attempt to resist the hunger. Neither case ends well. There are other cases in which instead the virus was left to stew in the body of the infectees for a very long while, with the same result. For extra added horror, the beings the second category produces? [[spoiler: ''Angels''.]]
* In ''VideoGame/{{Fallout 1}}'', if you tell your Vault's location to the Super Mutant leaders, you get a NonStandardGameOver that involves being dipped in [[TheVirus FEV]] and turned into a Super Mutant yourself.
** Subverted in ''VideoGame/FalloutNewVegas: Old World Blues'', where the Courier has their heart, brain, and spine replaced with cybernetic parts just like the Lobotomites, but retains a psychic connection with their original brain. There's also a [[DummiedOut deleted]] [[MultipleEndings alternate ending]] where they would [[WeCanRuleTogether join the Think Tank]].
* In the WebGame [[http://www.kongregate.com/games/krangGAMES/i-saw-her-standing-there I Saw Her Standing There]] the love of your life has been turned into a zombie. [[spoiler: By the end of the game she turns you into a zombie. The epilogue states you're very happy together and that the two of you made pancakes.]]
* In the 'Conquest' ending of ''VideoGame/HyperdimensionNeptuniaMk2'' [[spoiler:Nepgear, having traumatically slaughtered pretty much everyone she cares about, up to and including her own sister, approaches the BigBad... who points out that she's essentially made herself the harbinger of the apocalypse, and the world is doomed by what she's done, no matter what happens next. [[CruelTwistEnding Roll credits.]]]]
* In ''VideoGame/TheElderScrollsIVOblivion'''s "Shivering Isles" Expansion, you are summoned by Sheogorath, Daedric Prince of Insanity to be his champion and defeat his other half. When you do he rewards you by turning you into himself. Though it doesn't seem to affect the game much except at certain points you can go into Madgod Mode. Otherwise the game still plays out normally. Gone further in ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'', the Dovahkiin meets the new Sheogorath who has at this point has fully transformed and seems to be a shell of his former self, though he isn't complaining. This is a first and only for Bethesda in which you actually meet the hero from a previous game.
* In the mid-1990s action-RPG ''[[Franchise/{{Thunderscape}} Entomorph: Plague of the Darkfall]]'' the hero is trying to protect survivors of recent magical catastrophe from (more or less sentient) giant insects that went out of control. He is obviously too weak for this task and ends up needing to consume various body-altering drugs that gradually transform him into a giant insect.
[[/folder]]

[[folder: Visual Novels]]
* ''VisualNovel/UminekoNoNakuKoroNi''. [=EP5=]. [[spoiler:Battler, you may have forgot, but you were supposed to deny witches, not become one.]]
[[/folder]]

[[folder: Web Comics]]
* In ''Webcomic/TheOrderOfTheStick'', the character [[spoiler:Durkon Thundershield]] is shown to dislike the undead very strongly. During the events in Girard's dungeon, he is [[spoiler:killed and reanimated as a vampire.]]
[[/folder]]

[[folder: Web Original]]
* Attempted by Chief in ArbyNTheChief, when his Machinima character, also named Jon, becomes an alien after fighting in a war against them. The effect was [[CrowningMomentOfFunny not as he intended]].
* A skit from Those Aren't Muskets featured on ''Website/{{Cracked}}'', "Dealing with the Guy who's Clearly Hiding a Zombie Bite" ended as more and more members of the group revealed that they'd also been bitten by zombies, until the couple who hadn't been agreed to be bitten so as not to be left out. Of course as it turned out the original guy had also been bitten by a vampire and a werewolf. In the end, we had a group of three zombies, a werezompyre and a [[NinjaPirateZombieRobot mummy werezompyre that also happens to be a criminally insane android with holographic legs and a webshow]]. Michael Swaim can officially give Cyborg Pirate Ninja Jesus a run for his money.
* ''[[http://www.youtube.com/watch?v=0aQ3RqEOF44 Herobrine]]'' ends with [[spoiler: George Smith becoming a new Herobrine.]]
* The ''Machinima/RedVsBlue: The Recollection'' trilogy does this three times. [[BigBad The Meta]], a shell of a man now playing host to a group of rogue AIs, was once part of the project that produced them; Pvt. Church, who constantly complains about the AIs and the trouble they cause, [[spoiler:is revealed to be not only an AI himself (the Alpha), but the source of all the others]]; and finally, [[spoiler:the Alpha was based on the mind of the [[BiggerBad Director of Project Freelancer]], ''Doctor'' Leonard Church]].
* The first episode of ''[[{{Tobuscus}} Tobuscus Animated Adventures]]'' ends with Toby, who was bitten earlier by a zombie, turning into one and attacking his friend Gabe, interrupting the EverybodyLaughsEnding.
* In ''[[http://www.youtube.com/watch?v=nlIttRmS0Yc&feature=relmfu Gaston's Ultimate Mission to Obtain Some Taco Bell]]'', [[spoiler: Beast defeats Gaston by throwing him through a cliff and he is freed from his curse, [[MindScrew turning into]] Gaston]].
[[/folder]]

[[folder: Western Animation]]
* Finn and Jake of ''WesternAnimation/AdventureTime'' are both turned into Lumpy Space People by the end of "Trouble in Lumpy Space". They got better.
** Also in the ''Adventure Time'' episode "Mortal Folly/Mortal Recoil" Princess Bubblegum sends Finn and Jake to fight the Lich. In the end Bubblegum is turned into the Lich's vessel. She too, gets better ([[FountainOfYouth sorta]]).
* ''WesternAnimation/FamilyGuy's'' parody of ''Series/{{Lost}}'' - "We are the island!"
* Parodied in ''WesternAnimation/InvaderZim'' in the episode "Bolognius Maximus" in which the title character and Dib transform into bologna. The DVDCommentary hangs a lampshade on this.
* In the ''WesternAnimation/SouthPark'' episode "Ginger Kids," after Cartman starts a crusade against gingers, the other boys try to stop him by dying his hair red and using makeup to turn his skin pale and freckly. But then Cartman just changes his tune, starts a "ginger power" movement, and tries to wipe out all non-gingers. He stops and begins preaching tolerance after Kyle explains to him that he's not really a ginger.
** [[spoiler: Which later becomes ironic after "201" when Cartman finds out from his rival, Scott Tenorman, that he is his half brother through Scott's father (Cartman'a mom sleeping around, etc) whom Cartman had killed to get back at him. Both Scott and his father are gingers meaning Cartman is half-ginger.]]
* In one episode of ''WesternAnimation/CodeLyoko'', Xana's latest possessed victim is Yolanda, the school nurse, and Jeremie gets the idea of using Franz Hopper's notes to fight her on Xana's terms, in effect, using Lyoko's technology to give Odd the same powers as someone under Xana's control. Like everything Jeremie tries to do using Hopper's incredibly advanced and complex experiments, this nearly ends in a disaster. (Fortunately, Odd is able to recover.)
* When zombies attack the Mystery Shack in ''WesternAnimation/GravityFalls'', Soos gets ready to defend it with [[GenreSavvy knowledge he's accumulated from watching horror movies all his life]]. But before he can do anything, he's bitten and becomes zombified, and remains so for the rest of the episode, although a cure is mentioned at the end and he returns good as new for the next episode.
-->'''Soos:''' Dudes, stay calm. I’ve been training for this movie my whole life. With all of the horror movies I’ve seen, I know ''literally'' everything there is to know about how to avoid zombies.\\
'''Zombie Behind Soos:''' [[TemptingFate (CHOMP!)]]\\
'''Soos:''' Second thought, gonna flip the script. Can I eat your brains: Yay or nay? [[AffablyEvil Seeing some ‘yay’ faces over here.]]
[[/folder]]
----

-->I need to add tropes!
-->No, troper, you are the tropes.
-->And then troper was a trope.

----