History Main / BecomingTheCostume

* ''Fanfic/ThisBites'': In the third Halloween special, [[Manga/OnePiece the Straw Hats]] (and many allies) are transported to HalloweenTown from ''Film/TheNightmareBeforeChristmas'', and this ensues.

* In Creator/SeananMcGuire's Patreon-exclusive short story "Face Your Furs", an unnamed theme park implants {{nanites}} into the {{Goofy Suit}}s employees wear to turn them into PettingZooPeople. This is all [[ReadTheFinePrint perfectly legal]], but complications arise when [[spoiler:the transformation turns out to be irreversible]].

* From the satirical Venezuelan blog ''[[Blog/ElChiguireBipolar Chigüire Bipolar]]'''s article [[http://www.elchiguirebipolar.net/03-03-2014/nino-se-disfraza-de-gnb-y-le-pega-a-su-mama-abuela-y-perrito/ *Boy disguises as National Bolivarian Guard and hits his mother, grandmother and doggy]], both the title's boy and his sister who was dressed up as a member of radical opposition.

* In one of the Franchise/DoctorWhoExpandedUniverse books, ''Forever Autumn'', this happens because of some strange occult-sciency aliens wanting to harvest fear from everyone so they can leave Earth. Yes, ClarkesThirdLaw is in effect here.

* The ''Literature/{{Goosebumps}}'' book ''The Haunted Mask'' and its sequel (also adapted for TV) has this as a plot point, in which the mask the victims wear in each book can only be removed by a symbol of love.

* The ''Literature/XanaduStoryverse'' is all about this. At [[https://shifti.org/wiki/Xanadu_(setting) a costume convention]] with ten thousand in attendance, costumes become real and those wearing them are changed. Mentally the transformation varies from person to person, from "Suddenly my costume is much more accurate" to "Where am I, what is this planet?", due to each costumed person technically being turned into what they perceived their costume as being -- as such, two people in the same exact costume would still turn into different things based on their knowledge and interpretation of the character they had come as, how "in-character" they were, what they were thinking or doing at the moment they transformed, and so on. There is also the "clothing curse", which affected some, but not all, of the transformed people and caused any clothing they put on to transform in the closest equivalent that would be "appropriate" for their character to wear[[note]]so for instance anything a Jedi would put would transform into a set of robes[[/note]]. Stories tend to be either UsefulNotes/{{furry|Fandom}} or WelcomeToTheRealWorld.

* ''Literature/WearAndScare'': The concept is that kids buy some costumes from a mysterious shop, and eventually they turn into the creatures they are dressed as.

Not to be confused with BecomingTheMask or EvilCostumeSwitch. Can overlap with TheMindIsAPlaythingOfTheBody, which is [[FaceMonsterTurn bad news]]. Related to EvilMask. [[HilarityEnsues Hilarity might ensue]] if overlapped with ForHalloweenIAmGoingAsMyself.

** ''Fanfic/ASparkOfGenius'': Xander dresses as a "gentleman adventurer" and is transformed into a ''Webcomic/GirlGenius'' oc -- an Agatha and Gilgamesh kid, specifically -- and [[MadScientist a Spark]].

* In ''WesternAnimation/TheFairlyOddParents'' Timmy wishes for this to happen on Halloween -- unfortunately for him, his wording of the wish prevents him from unwishing it. He wanted everyone's costumes to be "real and scary"... and his fairy god parents just had to dress as a "floating human janitor" and a "floating human nurse". Even worse, the popular kids were dressed as Crash Nebula villains capable of forming a doomsday device that can blow up a planet.

* ''VideoGame/{{MGCM}}'': In the collaboration event with ''Manga/TheQuintessentialQuintuplets'', when the 6 heroines get the quintuplets' and Raiha's cosplay dresses, their personalities become like the quintuplets and Raiha.

* This is the entire plot of a downloadable game called ''The Theater''. It can be downloaded [[http://www.testzero.net/p/histrionica.html here]] or [[https://rpgmaker.net/games/4051/ here]].

--->'''Sunset:''' "What have we learned, Twilight?"\\

** ''FanFic/AnAverageEverydaySupergoddess'' focuses on a secondary character, Harmony Kendall, whose transformation for reasons unknown doesn't reverse at the end of the night, leaving her permanently stuck as Amora the Asgardian Enchantress.
** In ''Fanfic/ASparkOfGenius'', Xander dresses as a "gentleman adventurer" and is transformed into a ''Webcomic/GirlGenius'' oc -- an Agatha and Gilgamesh kid, specifically -- and [[MadScientist a Spark]].

* An ''WesternAnimation/EquestriaGirls'' fanfic ''Fanfic/YouCallThatACostume'' features Sci-Twi trying to make the Main 7's costumes more realistic, only for her spell to make them ''too'' realistic: Sunset becomes Starswirl the Bearded, Rainbow Dash becomes a werewolf, Fluttershy becomes a giant vampire bat, Rarity becomes a cowgirl, Applejack becomes a debutante, Pinkie Pie turns into Hyde-like persona Pinkamena, and Sci-Twi gains the form of Midnight Sparkle.
* ''Fanfic/NotTheIntendedUseZantetsukenReverse'': In [[https://www.fanfiction.net/s/11960165/21/Not-the-intended-use "OMAKE 3 Halloween"]], a fairy threatens everyone attending the party that she'll turn them into their costumes, but everyone decided that ForHalloweenIAmGoingAsMyself, and just stares at her.

* The concept of ''Literature/WearAndScare'', where kids buy some costumes from a mysterious shop, and eventually they turn into the creatures they are dressed as.

* In ''ComicBook/{{Silverblade}}'', the longer Jonathan remains in the form of one of his movie characters, the more he starts to believe he is that character. While in the form of Franchise/{{Dracula}}, he gets staked through the heart and 'dies' (because that would have killed Dracula in the film). When Milestone finds his skeleton and removes the stake, that 'revives' Dracula (again because it would have in the film). However, because of the the time he has sent 'dead', Jonathan now believes he truly is Dracula.

* Website/{{Fenspace}}: This is a possible result of handwavium accidents. The most drastic example to date is [[http://www.fenspace.net/index.php5?title=Wave_Convoy a guy]] who built a Trasformer using handwavium and got shot by a police sniper after being mistaken for a terrorist. He passed out in the cab, with a burst pipe leaking handwavium into the wound, and woke up with his mind now in the Transformer body. Likewise, [[http://www.fenspace.net/index.php5?title=Shuko the first catgirl]] was created when a con-goer in a handwavium-enhanced catgirl costume ate food contaminated with Guacamole (a strain of 'wavium specialized for bio-modification), and [[http://www.fenspace.net/index.php5?title=Jet_Jaguar another guy]] became a cyborg when he [[AlcoholInducedIdiocy accidentally]] drank a bottle of handwavium while wearing a suit of PoweredArmor.

* The ''Literature/XanaduStoryverse'' is all about this. At [[http://shifti.org/wiki/Xanadu_(setting) a costume convention]] with ten thousand in attendance, costumes become real and those wearing them are changed. Mentally the transformation varies from person to person, from "Suddenly my costume is much more accurate" to "Where am I, what is this planet?", due to each costumed person technically being turned into what they perceived their costume as being -- as such, two people in the same exact costume would still turn into different things based on their knowledge and interpretation of the character they had come as, how "in-character" they were, what they were thinking or doing at the moment they transformed, and so on. There is also the "clothing curse", which affected some, but not all, of the transformed people and caused any clothing they put on to transform in the closest equivalent that would be "appropriate" for their character to wear[[note]]so for instance anything a Jedi would put would transform into a set of robes[[/note]]. Stories tend to be either UsefulNotes/{{furry|Fandom}} or WelcomeToTheRealWorld.

* ''ComicBook/{{Hellblazer}}'': Happens at a [[AttackOfTheTownFestival revived pagan festival]], to the detriment of everybody. [[spoiler:(New father in baby costume to infant: "You're taking all of mummy's attention and it's! not! fair!" *splat*; a dentist(?) with a rictus grin mask wants [[StepfordSmiler EVERYONE]] [[GlasgowGrin TO]] [[SlasherSmile SMILE!]]). This isn't transformation, but rather a crazy-making signal coming from the nearby underground nuclear base. John and his friend discover that [[ThePowerOfRock loud punk rock]] cancels the effect a little too late: an ex-fighter pilot is "cured" just seconds after he releases a bomb, destroying the town and everyone in it (except John, of course).]]
* In ''ComicBook/{{Silverblade}}'', the longer Jonathan remains in the form of one of his movie characters, the more he starts to believe he is that character. While in the form of Franchise/{{Dracula}}, he gets staked through the heart and 'dies' (because that would have killed Dracula in the film). When Milestone finds his skeleton and removes the stake, that 'revives' Dracula (again because it would have in the film). However, because of the the time he has psent 'dead', Jonathan now believes he truly is Dracula.

* Like ''Buffy'' fans before them, the ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' community made this popular as a way to make their characters into powerful villains, or, less commonly, heroes.
** ''Fanfic/OversaturatedWorld'': In "[[https://www.fimfiction.net/story/323071/74/group-precipitation/living-nightmares-by-jenna-cipher Living Nightmares]]", Twilight performs an experimental costume-related spell that results in the creation of Darth Rarity, Sweetie Skywalker, Chief Engineer Applebloom 'Scotty' Scot, Invader Spike, and Rainbow Caboose.

** ''Fanfic/RainbowDoubleDashsLunaverse'': ''Costumes'' revolves around this trope. In an attempt to promote her wares, Rarity uses a Zebrican ritual that she thinks will make her costumes more realistic. Unfortunately, in something of a RunningGag for the Lunaverse, she misunderstands the ritual's function -- it was designed to allow a zbra to take on the physical form and powers of a totem. So everyone wearing one of Rarity's costumes (and most of Ponyville was wearing one of Rarity's costumes) is turned into whatever they were dressed up as, and gains whatever abilities they subconsciously believed their new form should have. Rarity, for example, is turned into [[OurVampiresAreDifferent a vampony]] and gains hypnotic eyes and blood-sucking fangs. Further, the spell causes all victims to believe that they actually are whatever they'd been dressed as. Luckily, Trixie and Twilight had made their own costumes and are able to dispel the curse. But not before several adventures occur...
*** Snips and Snails had dressed as Captain Equestria and Spiderstallion, while Raindrops was in disguise as Princess Platinum. When Raindrops!Platinum is kidnapped by a pack of diamond dogs (formerly the workers of Sweet Apple Acres), the two superheroes rescue her. Snips!Captain even gets a kiss out of it... right as the magic's dispelled, so Raindrops ends up kissing Snips.
*** Cherilee, now Catmare, attempts to rob a jewelry store before running into Batstallion (formerly Heavy Roller) and Robin (formerly Scootaloo). They successfully catch her after an innuendo-laden fight, only for Carrot Top to show up transmuted into Poison Ivy. Carrot!Ivy takes Batstallion prisoner with her spores, expressing an interest in feeding him to her plants. Cherilee!Catmare can't have that, as she has her own designs on Batstallion's body. The ritual comes undone right in the middle of the final fight between Catmare and Robin on one side, and Poison Ivy on the other.
*** Lyra and Bonbon had dressed up as [[Film/BonnieAndClyde Bonnie and Clydesdale]]. In that guise, they successfully rob the Ponyville bank, leaving the teller tied up behind them. They just finish enjoying some celebratory sex when Dinky!Holmes and Ditzy!Watson show up and incapacitate them. Dinky!Holmes then rounds things off by apprehending the teller, who'd been embezzling from the bank. That chapter ends with Bonbon worriedly rubbing her abdomen after the magic is reversed.
** An ''WesternAnimation/EquestriaGirls'' fanfic ''Fanfic/YouCallThatACostume'' features Sci-Twi trying to make the Main 7's costumes more realistic, only for her spell to make them ''too'' realistic: Sunset becomes Starswirl the Bearded, Rainbow Dash becomes a werewolf, Fluttershy becomes a giant vampire bat, Rarity becomes a cowgirl, Applejack becomes a debutante, Pinkie Pie turns into Hyde-like persona Pinkamena, and Sci-Twi gains the form of Midnight Sparkle.

* ''Series/{{Community}}'': Abed is probably worth an honorable mention. He dresses up as Batman the Halloween episode "[[Recap/CommunityS1E07IntroductionToStatistics Introduction to Statistics]]", and although technically he never actually turns into Batman (despite appearances, it's not that kind of show), he commits to the part to such a degree that some of his friends start to think he actually believes it. But then, he ''is'' known for his [[AmbiguousDisorder rather]] [[CloudCuckooLander unique]] [[MetaGuy view]] of reality.

* From the satirical Venezuelan blog ''[[Blog/ElChiguireBipolar Chigüire Bipolar]]'''s article [[http://www.elchiguirebipolar.net/03-03-2014/nino-se-disfraza-de-gnb-y-le-pega-a-su-mama-abuela-y-perrito/ *Boy disguises as National Bolivarian Guard and hits his mother, grandmother and doggy]], both the title's boy and his sister who was disguised as radical oppositor.

* Overlaps with DraggedIntoDrag on sites like Big closet top shelf all the time.
* In general, this is a favorite [[HalloweenEpisode Halloween event]] for JournalRoleplay games.

Not to be confused with BecomingTheMask or EvilCostumeSwitch. Can overlap with TheMindIsAPlaythingOfTheBody, which is [[OhCrap bad news]]. Related to EvilMask. [[HilarityEnsues Hilarity might ensue]] if overlapped with ForHalloweenIAmGoingAsMyself.

%%* The ''Literature/{{Goosebumps}}'' book ''The Haunted Mask'' (also adapted for TV) has this.

* The TV special ''WesternAnimation/WitchsNightOut'' (1978) has a witch turn two kids and their babysitter into the monsters they're costumed as. When the adults find out and turn on her, she explains that the point of Halloween is to try out different personas and imagine your potential. The adults happily start calling out requests for one-night transformations themselves.
* ''WesternAnimation/LiloAndStitchTheSeries'': In the episode "Morpholomew", after capturing the title Experiment, Lilo decides his "one true place" is at the local costume shop, where he uses his powers to physically transform people into whatever character they want to dress as.

** In the third segment of "[[Recap/TheSimpsonsS17E4TreehouseOfHorrorXVI Treehouse of Horror XVI]]", "I've Grown a Costume on Your Face," a witch curses everyone in town by making them become their costumes.

* VideoGame/TalesSeries:

* ''Film/{{Clown}}'': Kent [=McCoy=], upon donning a Clown costume to stand in at his son's party, goes from a loving father to a child eating demon under the influence of the "costume" [[spoiler:which turns out to be literal skin and hair from an Ancient European Demon]].