%% Image selected per Image Pickin' thread: http://tvtropes.org/pmwiki/posts.php?discussion=1298066706074520100
%% Please do not change or remove without starting a new thread.
[[quoteright:182:[[Manga/ElfenLied http://static.tvtropes.org/pmwiki/pub/images/Lucy_Nyu_split_8125.jpg]]]]

->''"There's just one problem... you're talking to the wrong Harvey."''
-->-- '''Big Bad Harv ([[ComicBook/TwoFace Harvey Dent]])''', ''WesternAnimation/BatmanTheAnimatedSeries''

In real life, [[https://en.wikipedia.org/wiki/Dissociative_identity_disorder Dissociative Identity Disorder]] (or DID) is a condition believed to be most common among survivors of severe and/or chronic trauma occurring before the age of 6-9. There is [[http://en.wikipedia.org/wiki/Dissociative_identity_disorder#Controversy some controversy as to whether or not it even exists]]. While typically depicted as rare and often misdiagnosed due to lack of education among clinicians, the disorder is actually estimated to occur in 1 to 3% of the population worldwide, placing it on a similar scope to autism and obsessive-compulsive disorder.

As it is understood in modern psychology, the condition is thought to sometimes result when a child/teen copes with abuse by convincing himself that it's happening to someone else; as such, the trigger is generally some experience the child/teen is trying to [[RuleOfScary dissociate himself from]] by means of creating [[ImaginaryFriend an "alter ego" who gets put in charge]]. (The multiple personalities form the source of the disorder's original name, "Multiple Personality Disorder"; it was changed because the new name provides a better explanation of motivation.) Note that without receiving psychological counseling, the symptoms will carry over into adulthood. The individual has no control (at least initially) over when the personalities "switch" and may not initially remember what happens to him while they are switched. To put all that in Tropese: you go to your HappyPlace while some poor RedShirt has to deal with the TraumaCongaLine or HumiliationConga -- so stereotypically, the personality [[BeingTorturedMakesYouEvil who has to deal with it is not a nice person]]...

But that's not entertaining, so television does it differently, and in several different ways. Two (or more) personalities may be sharing memory or [[AlternateIdentityAmnesia not sharing memory]] or have access to each other's memory as external to their own in symmetric or asymmetric fashion, they can switch at will or involuntarily and be in clear war or some form of pact. It even may be the very same personality (i.e. having the very same mind, memory, and desires), but changing 'behavior mode' between several clearly distinctive states.

Characters with a split personality are surprisingly common in fiction, but most of them don't quite match the textbook definition of DID. [[ScienceMarchesOn In older media]], it will often be called "schizophrenia" even by psychologist characters, despite the fact that they are ''completely different disorders''. In schizophrenia, the person experiences auditory and sometimes visual or tactile hallucinations. (The word [[YouKeepUsingThatWord schizophrenia]] literally means "split mind," because a main symptom is scattered, unconnected thoughts.)

See also DoubleConsciousness, IdentityAmnesia, JekyllAndHyde, NapoleonDelusion, SuperpoweredEvilSide, SplitPersonalityMerge, SplitPersonalityMakeover, SplitPersonalityTakeover, and TalkingToThemself. If the split personality is the antagonist, it's the EnemyWithin. {{Shapeshifting}} is sometimes involved. If the personalities are flipping back and forth, FlipPersonality often ensues.

Compare TraumaInducedAmnesia.

If the two personalities are aware of each other, expect a GollumMadeMeDoIt situation to develop. Resolving it may require the weaker of the two to say "ImNotAfraidOfYou!" If the SplitPersonality gets its own body, it becomes either a LiteralSplitPersonality or an EnemyWithout (if said personality is antagonistic or [[SuperpoweredEvilSide evil]]). See also HeroicSafeMode for one explanation as to how a side like this can be created.

%%% Zero Context Example entries are NOT allowed on wiki pages. All such entries have been commented out.
%%% Add context to the entries before uncommenting them.


[[folder:Anime and Manga]]
* ''Manga/AirGear'': The perky, happy Akito has another personality, the violent and curse-spewing Agito, who was created after his older brother locked him in a cage and forced him into fighting against other AT users. Who's in charge can usually be indicated by his EyepatchOfPower (Agito's is over the left eye, and Akito's is on the right). [[spoiler:The manga, however, went even further and introduced a ''third'' personality named Lind, who seems to be [[OnlySaneMan more mature and worldly]] than the two of them.]]
* Nobara Ibaragi in ''Manga/AliceAcademy'' has some sort of split personality -- one personality adores and wants to protect Mikan, and the other does whatever her evil 'teacher' tells her to do.
* From ''Manga/AkumaNoRiddle'', Mahiru/Shin'ya Banba. By day a ShrinkingViolet, by night an aggressive psycho.
* ''Manga/AngelSanctuary'': An interesting subversion with Alexiel and Setsuna. Setsuna is (currently) the dominant persona while Alexiel steps occasionally as his [[SuperpoweredEvilSide Superpowered Badass Side]] whenever he's in over his head. Although each has a completely [[IdiotHero different]] [[LadyOfWar character]], Setsuna still occasionally echoes some of Alexiel's words and personality, proving that they really are the same person deep down.
* ''Manga/AttackOnTitan'': Eventually revealed to be true for [[spoiler:Reiner Braun, who is also the Armored Titan who broke down Wall Maria]]. It's played a bit more realistically in that it developed due to trauma, in this case [[spoiler:the extreme guilt of having broken down the Wall and unleashing the Titans on who he now realizes are ordinary, innocent people]], and the two personalities are not two distinct identities but rather two aspects of the same person. He labels one "the Soldier" (the loyal member of the army within the walls who fights the Titans), and the other "the Warrior" (his true personality).
%%%* Gaia/Nomura from ''Manga/BakiTheGrappler''.
* ''Manga/BlackLagoon'''s favorite CreepyTwins, Hansel and Gretel, crank their typical NightmareFuel on this trope and share split personalities with each other. They could decide themselves who wanted to be Hansel and who wanted to be Gretel at the time, to the point that there is WildMassGuessing as to which one was actually which at any given point during their story arc. There are even some that believe that both were the same gender, as to which that is left up to debate.
* ''Manga/{{Bleach}}'': The swords used by Shinigami, Zanpakuto, reflect their wielders' nature in weird ways. It's possible, though extremely rare (as in, only two canon examples) for a Zanpakuto to have two spirits inhabiting the weapon. The primary example is Ichigo's Tensa Zangetsu, which is split between the "Hollow Ichigo" spirit ([[spoiler:the true Zangetsu that reflects Ichigo's power as a Shinigami]]) and the "old man in black" spirit ([[spoiler:the reflection of a piece of Yhwach trying to take possession of Ichigo's power]]). Usually, when Ichigo goes into his MentalWorld, the two spirits share the same body, which changes form depending on who's in control. [[spoiler:However, in the final arc Ichigo learns his Zanpakuto's, and by extension his own, true nature and accepts both as extensions of himself. The autonomous Zangetsu spirits are never seen again, implying a SplitPersonalityMerge with each other and their wielder.]]
* In the {{Hentai}} manga series ''Bondage Fairies'', the fourth manga -- ''Extreme'' -- introduces Urushira, an old flame of Pamila's. By day, she's a [[{{Meganekko}} sweet]] and caring [[HospitalHottie doctor]]. [[spoiler:At night, her other personality -- a nymphomanic PsychoLesbian who is oh-so-very {{Yandere}} over Pamila -- takes over. And when she wakes up the next morning, she doesn't remember a thing that her dark side did last night.]]
* In ''Manga/CardcaptorSakura,'' [[spoiler:Yukito Tsukishiro]] turns out to be the "disguise" of [[spoiler:Yue, Kero's counterpart]]. [[spoiler:Yue changes into Yukito on purpose, but Yukito has no idea Yue exists and cannot remember anything that happens to Yue. He doesn't know that his [[BigEater comically large appetite]] is due to his actually eating for two (the other being a powerful magic-user).]] He later comes to realize what goes on [[spoiler:when Touya gives his powers to Yue so neither he nor Yukito would disappear]].
* Motoko in ''Manga/Change123'' has three split personalities named Hibiki, Fujiko, and Mikiri -- collectively known as [=HiFuMi=] (1, 2, 3) -- that materialize whenever she's in danger. These split personalities come from her TrainingFromHell under three different adoptive fathers. Changes in hairstyle, muscle structure, and cup size come with it[[note]] Also, in the colored promotional panels, their [[MoodRingEyes eyes]] and [[KaleidoscopeHair hair]] usually have different colors. (See "Color-Coded For Your Convenience" item in this manga's "[[Characters/Change123 Characters]]" sub-page!) [[/note]], along with martial arts styles -- each personality, other than Motoko, are martial arts masters in a single specific field.\\
[[spoiler:A 5th personality emerges at one point called [[MyHeroZero Zero]]. Zero represents all of Motoko and [=HiFuMi=]'s negative emotions, and is [[AxCrazy very unstable]] -- oh, and she has ''all'' the other personalities' martial arts expertise, ''at the same time'', and is super strong, to boot. Later, it's discovered that Zero is actually Motoko's first split personality, her [[JekyllAndHyde "Mr. Hyde"]], created when she forcibly locked away her anger (because she superstitiously believes that her anger killed her mother).]]
* In ''Manga/Classi9'', Franz Liszt's personality changes completely when he touches the piano. Chopin says he looks "possessed", and it turns out Demon!Liszt is a separate person, or at least sees himself as such. Regular!Liszt usually doesn't remember his performances and is extremely sorry for the damage his alter-ego has caused even if he has no idea what happened, whereas Demon!Liszt is aware of Regular!Liszt and his past actions.
* ''Manga/CountCain'' reveals in its WhamEpisode that [[spoiler:the Riff that all the characters knew was actually a fake personality, created by the Delilah Organization. The real Riffael was an awful, cruel man, and when he's reawakened, he immediately betrays the protagonists.]][[note]]Many readers suspect that this was partly The Tower being duped like he was over the zombie thing, and that while 'the original' wasn't the greatest guy, he was a more normal human being than either of his halves. [[spoiler:Thus, Riff cutting his wrists in guilt over surviving his family, even though he doesn't remember that he set the fire, is an enaction of Riffael Raffit's self-hatred that he was too proud to express and The Tower doesn't even feel anymore.]][[/note]]
* Tyki Mikk of ''Manga/DGrayMan'' has commented how having a light side and a dark side makes life more fun. He can be a perfectly ordinary, personable man, but is also a tremendous sadist and has killed at least five Exorcists, including one of the Generals. Most of the other [[WhatDoYouMeanItsNotSymbolic Noah]] have similar SplitPersonalities, albeit somewhat less extreme.
* [[spoiler:Shiro]] from ''Manga/DeadmanWonderland'' seems to have a violent, deadly SplitPersonality created to deal with her DarkAndTroubledPast. [[spoiler:This is revealed to be just an act. In reality, [[{{Yandere}} Shiro's violent antics were acts of jealousy toward Ganta for being able to live the privileged life she never had.]] Her actions as the Wretched Egg were also meant to strengthen Ganta up [[DeathSeeker so he could eventually fulfill her wish by killing her.]]]]
* In episode 12 of ''Manga/DeathNote'', Light agrees to place himself under surveillance due to the possibility of "another him killing people in his sleep". Played straight with Light as himself and as Kira are completely different people.
* What about mild-mannered Negishi from ''Manga/DetroitMetalCity'', whose alternate personality Johannes Krauser II is the badass and feared leater of a Death Metal band?
* On ''Manga/DragonBall'', the character Lunch (or Launch, [[SpellMyNameWithAnS depending on the translation]]) would go from a sweet, naive, blue-haired (or black-haired in the manga) girl to a hot-tempered, gunslinging, criminally-inclined blonde ([[FanNickname dubbed]] "Kushami", Japanese for "sneeze", by fans) and back again [[SneezeOfDoom whenever she sneezed]].
** In ''VideoGame/DragonBallFighterZ'', the Third Arc reveals that this is the case for [[spoiler:Android 21. The first two arcs portray her as having a soft and naive facade, but it is revealed that she actually has an evil half that fuels her insatiable hunger that is slowly taking over. Part-way into the arc, they split into two physical beings, freeing the base Good 21 but unleashing the super-powerful Evil 21 unto the world]].
* Nyu/Lucy in ''Manga/ElfenLied''. One has the mental capacities of a small child, the other's an insanely powerful killer out to take out a significant portion of humanity. [[spoiler:It turns out that [[OnlyKnownByTheirNickname Kaede]] is actually a fairly neutral identity, who's just been listening to a third OmnicidalManiac personality that wants to end all life.]] It seems that most, if not all of the diclonii have a "neutral" personality and their inner voice that tells them to exterminate humans. Especially apparent in Nana's case, where, when pushed, she will become just as violent as any of the others.
* ''Anime/ExcelSaga'':
** Parodied in one episode in which a cute detective channels her late father whenever she puts on his hat.
** At the end of the series, Il Palazzo shows another kind of split personality, becoming possessed by his own desire to conquer. This was a definite case of a SuperPoweredEvilSide, along with elements of demonic possession.
** [[Manga/ExcelSaga In the manga]], which had more time for these things, the split personality is more of a subversion, the only real differences being the fashion sense and preferred targets -- neither are evil or good, and both are slightly insane. It's still a bit unclear how Lord Il Palazzo's personalities work in the manga: sometimes it seems that it's only a case of varying amnesia, vaguely remembering and forgetting things from his past, which shape his motives. But one consistent difference has been that sometimes he is fond of Excel and tries to get her to remember something (maybe), while other times he wants her gone. It's also unclear which personality, his caring or uncaring one, is his true personality.
* If the words of [[spoiler:[[BigBad Zeref]]]] in ''Manga/FairyTail'' are any indication, then [[spoiler:[[TheHero Natsu]]]] has one of these. Specifically, his SplitPersonality is [[spoiler:[[UltimateEvil E.N.D.]], '''E'''therious '''N'''atsu '''D'''ragneel, the most powerful demon Zeref ever created, leader of the genocidal guild called Tartaros, and who is currently sealed within his [[TomeOfEldritchLore Book of Zeref]]]], and it can only be awakened if enough "curse power" is gathered to force the seal open, [[spoiler:or if Natsu himself opens the book]].
* ''Manga/FruitsBasket'':
** Hatsuharu, the ox of the zodiac, who turns into 'Black Haru'. Black Haru usually comes out when he's angry, and while Haru is usually easy to get along with, no one can handle his other side.
** There's a milder version in Kagura, the boar, who is sweet and mostly caring but becomes possessive and quite occasionally violent when Kyo is around. Either {{tsundere}} to the extreme or possibly a bit {{yandere}}.
** Both could be considered oddly realistic takes, as well. Neither are shown to be aware of the changes, except from what others tell them (Kagura is even confused about why Kyo looked so beaten after one incident), and we've seen just what caused them to develop and [[BerserkButton triggers the changes]]. Haru's "Black Haru" personality developed as a result of verbal abuse and his overwhelming resentment of Yuki, and he only changes when angry ([[TheStoic harder to]] [[DeadpanSnarker achieve]] than it sounds). Kagura, on the other hand, switches when something threatens to expose that [[spoiler:she's trying to love Kyo to get over her past guilt]].
* [[spoiler:Hohenheim]] from ''Manga/FullmetalAlchemist'' is revealed to suffer a sui generis, [[UpToEleven mindblowingly over the top]] case of this. Long story short: [[spoiler:he is a human Philosopher's Stone; these are made out of many people's souls, so do the math]]. He has devoted most of his life to isolate, communicate with, and ''befriend'' each of these [[spoiler:''536329'' different people "living" within him]].
* Examples from the ''Franchise/{{Gundam}}'' franchise:
** In ''Anime/Gundam00'', Allelujah Haptism has a rather psychotic other half that he calls Hallelujah.
*** Additionally, [[spoiler:Marie Parfacy]] has one [[spoiler:named Soma Peries. Soma]] "goes to sleep" indefinitely in the second season and [[spoiler:Marie returns to be]] the one in control.
** Lady Une of ''Anime/MobileSuitGundamWing'' developed split personalities out of her love for her boss Treize, one a [[TheBaroness cold-hearted]], calculating ColonelBadass, the other a kind, soft-spoken peace advocate. She has a few moments of near breakdown before being shot roughly halfway through the series and remaining comatose until the final arc. The coma apparently gives her time to resolve her issues, and when she wakes up she has Iron Une's military and strategic skills and Saint Une's compassion and desire for peace. Her [[FourEyesZeroSoul glasses]] act as a trigger. Once she puts them on, you're guaranteed to see her order somebody's death.
* ''Anime/HanaukyoMaidTai''. The maid Grace/Cynthia has two personalities: Grace (highly intelligent and abrasive) and Cynthia (sweet, childlike, and mute).
* Yumie Takagi, berserker soldier of the Iscariot Organization in ''Manga/{{Hellsing}}''. The (not canon for the series) ''Cross Fire'' stories in the first three manga volumes involve her being brought out for various assassinations, to the dismay of her other personality, a thoroughly sweet nun named Yumiko.
* ''Manga/InuYasha'' has Suikotsu of the Band of Seven, who has three personalities: a kind and caring doctor who has no awareness of the other two (and is the original one), an ultra-violent killing machine who knows of the other two and despises his gentler personality, and an "in-between" personality who is aware of the others and serves the Band of Seven while remaining calmer and more rational than his bloodlusting counterpart.
* The BigBad in Part 5 of ''Manga/JojosBizarreAdventure'' has two personalities. There's Doppio, a borderline autistic, [[PsychopathicManchild childlike]] man, and Diavolo, a cunning, violent, and paranoid mafia boss. His [[KaleidoscopeHair hair color]], [[MoodRingEyes eyes]], and size change drastically and his Stand power changes form as well. Doppio communicates with Diavolo by holding random objects to his face like a phone (after hearing schizophrenic ringing).
* ''LightNovel/KaraNoKyoukai'':
** Averted: Tohko correctly identifies that what Shiki [[spoiler:used to have before her coma]] can't be dissociative identity disorder, given its complexity.
-->'''Shiki:''' There's nothing funny about having a dual personality.\\
'''Tohko:''' No, no. You know, you two don't have anything as pleasing to look at as dissociative identity disorder. Existing simultaneously, each having their own unique will, and on top of that your actions are coordinated. That sort of complex personality shouldn't be called a "dissociated identity," but rather a "united independent personality."
** Played straight with [[spoiler:Shiki's ''third'' personality in the epilogue, which she is unaware of and only surfaces when she's unconscious, making it closer to actual DID. The third personality is aware of her, but it's also omniscient, so you'd expect it to be.]]
* In ''Manga/{{Karneval}},'' [[spoiler:Yogi has one which causes him to unleash hell on whoever is unlucky enough to be fighting him. [[KaleidoscopeHair His usually gold hair turns silver as an indication.]]]]
* In ''Manga/KingOfThorn'', the English translation says Alice has schizophrenia, but it later becomes clear that it's actually DID -- being abused by her family caused her to develop an alternate personality called Laloo, who would take the abuse for her. After she became infected with Medusa, Laloo manifested as an EnemyWithout.
* In ''Manga/KotouraSan'', [[spoiler:Detective Tsukino has one, due to being bullied as a child. Her evil personality was in charge or revenge and was also the perp of the physical assaults on school girls in episode 10. [[IKnowYouAreInThereSomewhereFight With the help of]] [[ThePowerOfFriendship Haruka]], the [[SplitPersonalityTakeover good side is able to eliminate the evil one]] and she is even ready to turn herself in to pay for "her" crimes, which is refused by her superior, whom she has an apparently close friendship with.]]
* Irabu-sensei from ''Kuuchu Buranko'' has a total of three personalities: Stuffed Animal one, who acts silly and childish, Child one, who acts more serious and snarky, and Adult one, who is something in-between but leans closer to Animal one.
* Seijuro Akashi from ''Manga/KurokoNoBasuke'' seems to have an unnamed second personality. This is probably a result from his father demanding absolute perfection in everything he does, be it school, sports, music... When he was about to lose a 1 on 1 basketball match against his teammate Murasakibara, his second personality "the other Akashi" took over in order to ensure his victory. The "real" Akashi disappeared during that event and has only now resurfaced a few years later.
* ''Manga/{{Mahoraba}}'''s Aoba Kozue has five personalities, switching to one at random whenever she's shocked or surprised. Her [[KaleidoscopeEyes eye colors change]] for each personality, and each personality prefers to wear her hair differently. She switches back to normal by going unconscious. While each personality is pretty distinct from the rest, they all have several distinct traits they share, particularly a liking for her crush and a major thing for umeboshi.
* ''Manga/MahouSenseiNegima'':
** As of Chapter 284, [[spoiler:Asuna seems to have developed this as a result of having her LaserGuidedAmnesia forcibly undone: one is her "true" personality from before Ala Rubra rescued her from her life as a living weapon, and the other, currently dominant, is the Asuna we've come to know and love.]]
** Luna, too. [[spoiler:Ironically, her other personality is ''also'' Asuna.]]
* ''Manga/MPDPsycho'' really drives this trope to utter extremes. Some of the multiple personalities even [[spoiler:appear in other physical bodies, and this even when their original physical body has died]]. Which might make this manga a slight twist. (It's amazing what the average [[MegaCorp corporation]] can do while trying to [[spoiler:bring a NotQuiteDead rock musician back to life.]])
* ''Anime/{{Monster}}'':
** Johan is indeed a real person, but [[BunnyEarsLawyer Inspector Lunge]] (or [[SpellMyNameWithAnS Runge]]) is convinced that he is an alternate personality of Dr. Tenma.
** Wolfgang Grimmer, meanwhile, occasionally blacks out when physically threatened. When he recovers, everyone who threatened him is dead. He refers to the personality that takes over as "the Magnificent Steiner", after a show he watched as a child (where the title character is the superhero persona of an unknowing boy).
* This becomes the premise of ''Anime/NanakaSixSeventeen'', once the title character's original personality re-emerges early in the story, after a LaserGuidedAmnesia period in which she reversed to her 6-years old mindset. And in the manga only, [[spoiler:aside from the 6-year old personality, Nanaka develops in the second half of the story a ''second'' split personality, which names itself "Hiro"]].
* In ''Manga/{{Nanbaka}}'', [[spoiler:Nico is revealed to have another persona, violent in comparison, that appears when his medicine wears off.]]
* ''Manga/{{Naruto}}'':
** Zetsu is split down the middle between his two personalities. His right side is black, speaks in a deep voice, and is completely professional; his left side is white, talks in a lighter voice, and is a bit more carefree. The two halves can talk and even argue with one another and even [[LiteralSplitPersonality separate into two functional halves]]. [[spoiler:The black half is ultimately revealed to have been infused with the "will" of Madara prior to his death, while the white half is the original Zetsu]].
** Jugo is a cowardly person who cares about his friends with a separate personality that [[BloodKnight wants to fight and kill just for the sake of doing so]]. The split personality is a side effect of his bloodline but not directly linked to using its abilities.
* ''Manga/NectarOfDharani'': Sakra's Ambrosia has its own personality, which calls itself Shakuntala. She acts far older and wiser than Sakra, as well as with more cruelty, but seems to have Sakra's best interests at heart.
* ''Manga/OnePiece'':
** Usopp may be developing this. When it was first introduced, "Sogeking" was an assumed name and PaperThinDisguise Usopp used (the reasons are complicated). Usopp acted rather differently while in his Sogeking disguise, even managing to score his first ''real'' BigDamnHeroes moment before reverting back to his old, cowardly self after circumstances changed and he was able to remove the mask. During a later fight (as Usopp), he is actually depicted mentally arguing with Sogeking. Later still:
--->'''Usopp:''' ''[running away from Perona and Bearsy]'' Somebody, save me! Save me!\\
'''Sogeking:''' ''[tackling and purifying a ''goddamn zombie bear'']'' Save me, Sogeking!
** The Dressrosa Arc gives us [[spoiler:Cavendish and his SuperpoweredEvilSide Hakuba, the latter awakening whenever the former goes to sleep. It turns out that Hakuba is in fact the 'white horse' epithet that Cavendish claims, is twice as strong as Cavendish, and was responsible for all the killings that Cavendish [[AttentionWhore enjoyed anyway]].]]
** In the ''Whole Cake Island'' arc, it's become apparent that [[spoiler: Charlotte Pudding]]'s recent experiences [[spoiler: and her DarkAndTroubledPast]] have fractured her mind and led her to develop this. [[spoiler: after falling in love with Sanji for real, she rapidly goes back and forth between swooning over him and yelling death threats at him- sometimes at the same time! Luckily though, she's still cognizant enough to lend him a hand even as she lapses back into "evil Pudding".]]
* In the manga ''Manga/{{Othello}}'', the shy main character Yaya switches to her alter ego, bold and assertive Nana, when she sees her reflection.
* In ''Manga/PandoraHearts'', the [[spoiler:Baskerville Zwei's personality was split with magic after the clan's constant shunning and the frequent DemonicPossession from her chain had gone too far, leading the girl to snap.]]
* [[spoiler:The title character]] of ''Literature/{{Paprika}}'', who is the dream avatar of [[spoiler:Dr. Atsuko Chiba. Paprika is everything that Chiba isn't and secretly wants to be.]] And it gets better: [[spoiler: Paprika]] has characteristics of both [[spoiler:Chiba and Tokita]], hinting at the former's affections for the latter.
* ''Anime/ParanoiaAgent'' has a woman whose split personality (who is far more promiscuous and thrill-seeking) leaves messages for her on her answering machine; threating ones. [[NightmareFuel Frightening stuff.]] This is actually a moment where MPD is depicted accurately. There have been recorded cases of personalities threatening other personalities -- even going as far as causing bodily damage.
* In season 2 of ''Anime/PrincessTutu'', [[spoiler:Mytho]] starts to complain of "another me" being inside of him, [[spoiler:an evil personality that quickly begins to take over more and more]]. Later, it's revealed that it's actually [[spoiler:the result of one of his heart shards being tainted with Raven's blood]].
* Ayase and Luca Souju of ''Manga/PuellaMagiKazumiMagica'' are a pair of MagicalGirls with distinctly different powers and appearances, who manage to share one body to great effect.
* In ''Anime/PrettySammy'', we have Misao Amano, a ShrinkingViolet schoolgirl who transforms (unknowingly and involuntarily) into Pixy Misa, the [[BlackMagicianGirl evil magical girl]]. However, this trope is subverted when it is revealed in episode 19 that [[spoiler:her alter ego was in fact just the repressed aspects of her personality]], so the audience was led to believe that the Pixy Misa persona was due to brainwashing when in fact [[spoiler:Misa and Misao are one and the same]].
* ''Manga/ThePrinceOfTennis''' got a good one. Seigaku's Takashi "Taka" Kawamura is a kind-hearted guy whose father owns a sushi restaurant, but whenever he grabs a racket, his "burning" mode is turned on and he becomes Seigaku's top power player.
* One of Shiho's clients in ''Manga/PrivateActress'' has this. [[spoiler: As a child, an orphaned boy named Yuuto Tanabe was sexually abused by his CreepyUncle and ParentalSubstitute. As a result, he created a personality named "Shuuto" that dealt with extreme anger issues coming from the abuse, and under his influence [[TheDogBitesBack he burned his uncle's house and killed him]]. From then on, "Shuuto" and the original Yuuto co-existed more or less in peace, and Shuuto aka the now dominant personality shaped himself into a famous MrFanservice — until Yuuto took control back and fell in love with a GirlNextDoor, causing "Shuuto" to snap, [[SplitPersonalityTakeover fully take over their shared body]] and try hiring Shiho (pretending to be Yuuto ''and'' Yuuto's twin brother) to get Yuuto's would-be girlfriend away. And then it turns out there's a third personality, "Satoru", who has been lying dormant underneath the two, but wants to get this mess resolved...]]
* Inner Moka from ''Manga/RosarioToVampire''. Moka's Rosario acts as a barrier; [[DramaticNecklaceRemoval once removed]], Inner Moka comes out to kick ass.
* Gemini Saga, from ''Manga/SaintSeiya''. The specifics are never made terribly clear (i.e we don't know exactly how it developed and came to exist), but it takes hold of him and causes him to [[spoiler:murder and impersonate the Pope (not, not [[UsefulNotes/ThePope that Pope]]) for a number of years and generally act like a self-entitled asshole.]]
* ''Manga/SayonaraZetsubouSensei'':
** Kaere Kimura has a split personality that contains an [[EagleLand aggressive]], [[FrivolousLawsuit lawsuit-happy]] ForeignFanservice persona and an over-the-top YamatoNadeshiko persona. She apparently has even more personalities which depend on what country she is in.
** SZS managed to pull [[spoiler:the inverse of this: one personality split among many girls, thanks to Fuura being DeadAllAlong and her organs going to the girls in her class.]]
* Lain, the main character of ''Anime/SerialExperimentsLain'', seems to have several as the series progresses: shy, schoolgirl Lain, a very famous "Lain of the Wired" who's arrogant and powerful, and a manipulative and sadistic Lain. It turns out that [[spoiler:there are an endless number of possible Lains, as each and every person's perception of Lain, and each concept of Lain that arises via MemeticMutation in the Wired, becomes another one of her facets. Eventually, though, they undergo a SplitPersonalityMerge into a kind-hearted, but extremely powerful, Lain]].
* ''Manga/SgtFrog'':
** The "Other Momoka". Momoka appears sweet and harmless at first, but she hides an extremely jealous and possessive side that occasionally comes out when a perceived "rival" for the object of her affection appears.
** Momoka's mother turns out to be the same way, except she prefers to let her aggressive side be the default; this is the reason she doesn't live with her loved ones.
* Yamamoto Jun from ''Manga/SpecialA'' turns from a relatively shy guy to a [[TheCasanova Casanova]] whenever he is kissed by a girl. Later on, it seems to be when a certain girl just looks at him.
* Another classic {{Hentai}} manga, ''Super Taboo'', had Yuu Sakagami, a guy who had two distinct personalities. The first was his normal personality, and was governed by Reason. The other, his more evil and lustful side, was governed by instinct, and came out when one of his incestuous family members made him horny. [[spoiler:Eventually, the Instinct side became more violent and sadistic, leading to Yuu hurting his sister Eri, and his mother took action -- his father was the same way, and it turned him into a sadistic pervert that she couldn't live with. Eventually, the two sides had it out in a final showdown, and Reason ultimately won]].
* In the ''Manga/{{Trigun}}'' manga, we have [[spoiler:Livio and his SuperPoweredEvilSide, Razlo, which he developed as a child. His very distinct personalities cause him to be the last two members of the Gung-Ho-Guns.]]
* Maki Kisaragi from ''Manga/WChange'' is a GirlyGirl who likes sweets and handycrafts, and who has a dark split personality that is violent and loves to fight.
* ''VisualNovel/UtaNoPrincesama'' Maji Love 1000%: Natsuki is typically oblivious and, to an extent, airheaded. Despite his positive outlook on life, he gets discouraged quite easily. "Satsuki", his alter ego per say, comes out when Natsuki’s glasses are removed. Satsuki is harsh and combative, rumored to have put 50,000 people in the hospital for angering him.
* Examples from the ''Franchise/YuGiOh'' franchise:
** Dark Yugi in ''Manga/YuGiOh'' is initially presented as one of these, before it is revealed that he is actually the spirit of an ancient Egyptian Pharaoh. The same goes for Dark Bakura, who is actually the spirit of an ancient Egyptian Thief/Tomb Robber [[spoiler: combined with an EldritchAbomination]], but ''not'' Dark Marik, who is a more traditional split personality caused by childhood trauma. Ironically, Yugi's ''[[Anime/YuGiOhGX GX]]'' [[LegacyCharacter successor]] in the anime-only spin-offs is a true example.
** Sora from ''Anime/YuGiOhArcV'', maybe. Usually he's a nice guy, something of a bumbler, and unsure of his abilities. When actually dueling, however, his attitude turns far more serious and malevolent, [[SlasherSmile his appearance becoming menacing]] and his speech pattern sounding sociopathic, seeming to show sadistic pleasure in hurting his opponent. Possibly, this is due to his attachment to the Fusion Dimension.
* Shinobu Sensui in ''Manga/YuYuHakusho'' was a lawful yet pure and innocent young man before encountering the Black Book Club, rich men who tortured demons for fun. He couldn't bring himself to kill humans ([[WhatMeasureIsANonHuman as opposed to demons]]), and so developed another personality to do the dirty work. Over the years, he developed ''six'' alternate personalities, switching between them depending on the situation (I.e: [[spoiler:he used the MagnificentBastard "Minoru" to recruit his followers and pull strings, then when Yusuke managed to hit him he switched to the AxCrazy "Kazuya"]]). Each one has a different level of power; the original one, Shinobu, is the most powerful of them all... and [[PureIsNotGood is still an innocent]], as he let the others do the dirty work.
* There are two characters in ''Manga/ZettaiKarenChildren'' who suffer from split personalities: Sera (due to possession) and [[AxCrazy Phantom Daughter]] AKA [[EmotionlessGirl Mirage]] a.k.a. [[spoiler:[[OrdinaryHighSchoolStudent Yuri / The Doll]]]], [[BodySnatcher Feather]][[spoiler:is initially mistaken for one but was actually a different person or something]].
* Jamie Hemeros in ''Anime/ZoidsNewCentury'' develops a cocky ace pilot alter-ego named Wild Eagle who takes control during battles every now and then. Although popular opinion seems to suggest that this happens when Jamie breaks the sound barrier in his Zoid, Wild Eagle actually seems to appear only when Jamie gets overly stressed out in battle.

[[folder:Comic Books]]
* Jeanne-Marie Beaubier, aka Aurora of the Franchise/MarvelUniverse's ''ComicBook/AlphaFlight'', had at least two separate personalities when first introduced: the demure and timid "Jeanne-Marie" and the forthright and fun-loving "Aurora". Flashbacks in an early issue of ''Alpha Flight'' revealed that the "Aurora" personality split off from "Jeanne-Marie" after she was severely beaten by the nuns who were raising her. Originally, only "Aurora" had superpowers (not surprisingly, since the nuns had beaten Jeanne-Marie for telling them she could fly -- [[CassandraTruth she could, but they assumed she was lying]]), and if too much stress caused her to revert to the "Jeanne-Marie" personality in a crisis, it could cause serious problems. In her more recent appearances, she's shown signs of having a third, unnamed, personality, whose main characteristic is being psychopathically violent.
* ''Comicbook/TheAvengers'':
** Insane robot and villain ComicBook/{{Ultron}}. Every model has a new, different personality, culminating in one version which contained ''every'' previous personality constantly vying for supremacy, making him eight unstable megalomaniacs in one.
** Ultron's creator and 'father' figure, [[ComicBook/AntMan Dr. Henry Pym]], underwent a period of insanity where he not only believed himself to be a different person, but claimed to have actually ''killed'' Pym. While this was eventually resolved, he's still not the most stable of people, [[spoiler:to the point that when he was Skrull-replaced, they went through multiple agents specifically because each one that imitated him eventually developed his mental problems and had to be eliminated to keep the cover from being blown.]]
** ComicBook/TheSentry and Void. The Sentry is 'The Golden Guardian of Good', blond haired, handsome, and heroic, his powers being strongest during the day. A fangirl's dream version of Legolas, wielding more power than [[UsefulNotes/TheSilverAgeOfComicBooks Silver Age]] Superman with added psychological problems, and a broader power set to boot, which is officially unlimited, facing down beings like Galactus and Green Scar (the latter when extremely agoraphobic) and winning or drawing. The Void is a pure evil, manipulative EldritchAbomination in semi-human form, strongest at night or in the Negative Zone, and is often described as akin to the Angel of Death. Both wield planet-busting power, and are immortal effectively by choice. Whenever the Void turns up or The Sentry looks like he's about to lose it, it's a MassOhCrap moment for the entire Marvel Universe.
*** Moonstone, a psychiatrist by trade, describes the Sentry/Void dichotomy as a 'split personality conflict playing itself out through comic book archetypes'. She also adds that it would be pathetic if the two weren't each able to destroy the planet.
%% * Norbert Sykes, aka ''ComicBook/TheBadger'', has at least five personalities.
* ''Franchise/{{Batman}}'' comics:
** ComicBook/TwoFace alternates between the just Harvey Dent and the maniacal Two-Face. Despite being the most well-known example, he is also an abnormal one, because as Two-Face, both of his personas, good and evil, are "on" at the same time (Usually. Two-Face is a huge case of DependingOnTheWriter). Coincidentally, his symptoms sometimes imply actual Schizophrenia, which doesn't exactly help clear the confusion people have about the two conditions.
** A few comics have suggested that SelfDemonstrating/TheJoker has multiple personality disorder, switching from a harmless prankster to serious threat and everything in-between.
** Even Batman himself has been accused of this. By day, he's [[RichIdiotWithNoDayJob Bruce Wayne]]. Put on the costume, and he's a completely different person. It's even [[Film/TheDarkKnightSaga been argued]] that the Batman persona is his "true" personality, and Bruce Wayne is the mask he hides behind. Creator/GrantMorrison's run on ''Franchise/{{Batman}}'' revealed that Batman, who [[CrazyPrepared prepares for]] ''[[CrazyPrepared everything]]'', deliberately cultivated a back-up personality should the Bruce Wayne/Batman persona be incapacitated.
** Arnold Wesker is a mild-mannered ventriloquist, and is ''utterly convinced'' that his psychopathic mobster alter ego, Scarface, manifests through his ventriloquist's dummy, rather than his own brain. Scarface often agrees with this, and the split personality's dependence on the puppet is so strong that the personality doesn't manifest outright when the puppet is missing or destroyed, although poor Arnold then feels a compulsion to replace it.
*** Some stories imply that Wesker is ''correct'', and the doll really is possessed by an evil spirit or spirits (in his last appearance, Wesker dies and the doll is burned... and gets up and walks before collapsing). And a couple suggest that Wesker is just acting and the doll is really just a ruse to convince everyone he is crazy. Much like SelfDemonstrating/TheJoker is sometimes accused of being, but given some of the stuff Scarface has put him through [[note]]At one point Wesker replaced Scarface with a sock puppet; Scarface returned and ''they shot each other'', leaving Wesker with bullet ridden hands[[/note]], Wesker would arguably be ''even worse.''
*** When Wesker replaces the Scarface dummy with a different puppet, the alternate personality is often different, and usually milder mannered.
** [[ComicBook/{{Azrael}} Jean-Paul Valley]] has, at most, three. There's Jean-Paul himself, a timid mild-mannered man who has a thing for electronics, there's Azrael, a SuperSoldier with no scruples about striking down evildoers and an archaic sense of doing things and there's "Batman", who has Jean-Paul's smarts, Azrael's strength and zero compassion. The last one tends to appear under duress.
* Jack Ryder [[DependingOnTheWriter sometimes]] sees ComicBook/TheCreeper as a completely different personality.
* Mary Walker, a supervillainess most commonly associated with ''Comicbook/{{Daredevil}}'', has three distinct personalities. The "Mary" personality is a timid, quiet, pacifist; her "Typhoid Mary" persona is adventurous, lustful, and violent; her "Bloody Mary" personality is sadistic, brutal, and hates all men. Typhoid was so different than Mary, that even Daredevil was, at first, unable to tell they were the same person, even with his enhanced senses. (It seemed that the change even affected her body odor somehow.)
* Shasti from Adam Warren's version of the ''ComicBook/DirtyPair'' is an ArtificialHuman deliberately engineered with four personalities for different tasks.
* Grant Morrison's run on ''Comicbook/DoomPatrol'' featured, among other characters, Kay Challis, also known as Crazy Jane, who had no less than 64 separate personalities, each with its own name and function, and after a "gene-bomb" was detonated during an alien invasion of Earth, [[DisabilitySuperpower each with its own superhuman ability]].
* Copycat from ''[[ComicBook/{{Gen13}} DV8]]'', whose five personalities are each represented by different fonts and word balloons. For the record, those personalities are: Standard, overburdened teenager; "Spy", analytical and task-oriented; "Soldier", aggressive and combat proficient; "Nihilist", rebellious and troublemaking; and "Little Gemma", essentially Copycat as she was at age 6. Ivana actually points out the HollywoodPsych at work, saying that Gem's condition doesn't resemble any case of Dissociative Identity Disorder she's ever read about. She theorizes it has something to do with her Gen-Factor mutating an existing psychological disorder.
* ''Franchise/GIJoe'' originally had a "Psychological Profile" for [[MasterOfDisguise Zartan]] that describes him as an "Extreme paranoid schizophrenic. Grows into various multiple personalities to such an extent that the original personality becomes buried and forgotten." Mental health groups complained, however, and Zartan's psychological profile had been dropped in later reprints of his general profile.
** One of Zartan's Dreadnoks is Road Pig, real name Donald [=DeLuca=]. This isn't mentioned in his toy profiles, but in the comics he's depicted as having two distinct personalities: thuggish half-wit Road Pig and cruel sophisticate Donald. They're aware of each other, and though there's not much they agree on, they both love wanton destruction and Zartan's sister Zarana.
* ''Comicbook/IncredibleHulk'':
** Dr. Bruce Banner is a different person when transformed into the Hulk. The comics take it to extremes, with different versions of the Hulk with different personalities: in addition to the traditional "Savage Hulk", there also developed a sneaky, amoral version called Joe Fixit (who was grey, like in the Hulk's first appearance). Eventually, the personalities were integrated into the "Merged Hulk", but this was {{retcon}}ned to be just another personality, the Professor (who had Banner's brainpower, Fixit's cunning, and most of Savage Hulk's strength).
*** Two other personalities in Bruce's lineup are the Devil Hulk, a reptilian creature that lacks any sense of guilt, and the Green Scar, who combines Fixit's cunning with the Savage's strength, and over time develops to become possibly the strongest Hulk incarnation of all.
*** Some have theorized that the Hulk is -- and always has been -- an embodiment of pent-up rage and aggression that Banner had felt all his life prior to the accident, mostly stemming from the abuse he and his mother suffered at the hands of his father. [[spoiler:Who Bruce killed by accident, but later admitted it ''might'' have not been an accident.]] In short, Banner and the Hulk may be more alike than Banner is willing to admit.
** The Hulk's son Skaar also has a split personality; "normal" Skaar is a Conan-style barbarian, while "puny" Skaar is an adolescent boy who hates his other self for his savage deeds.
** ComicBook/BettyRoss as Red She-Hulk. The degree to which she retains control over Red She-Hulk varies a lot. Sometimes it's just an angrier Betty, while at others it is an entirely different persona whom she fears losing control over.
** When M.O.D.O.K. placed Doctor Samson under mind control producea split personality. This led to a powerless Leonard who was defined as the good one and an evil Samson whose abilities are greater than She-Hulk's.
* Triplicate Girl/Triad from the ''ComicBook/{{Legion Of Super-Heroes}}'' tends to show signs of this trope when she [[DoppelgangerSpin splits apart]]. The version of her in the Post-''ComicBook/{{Zero|Hour}} [[CrisisCrossover Hour]]'' reboot was explicitly written as having three distinct personalities when split -- which was considered a mental illness on her [[PlanetOfHats homeworld]], although her grandmother insisted it was natural, and suppressing the different aspects was what was unhealthy. The current version takes this a little far; her entire civilisation consists of triplicates of the same person. The one/three who are members of the Legion, however, have had so many different experiences from the others that the rest won't let them rejoin.
* ''ComicBook/MoonKnight'' started off with the gimmick of having multiple secret identities. DependingOnTheWriter, this became a dissociative identity disorder, with Marc Spector, Jake Lockley, Steven Grant, and Moon Knight all being distinct personae. He also sometimes believes himself to be in communication with the Egyptian god who gave him his powers, but that might be another personality. Currently, the story is that he really ''is'' possessed by Khonshu, and his mind makes sense of this by constructing alternate personalities around Khonshu's various forms.
* The DCU also has had two different ''Rose and Thorn'' characters over the years, one whose Thorn persona was a villain, and a later one whose Thorn is a hero.
* Peter Milligan's reboot of ''ComicBook/ShadeTheChangingMan'' has this in droves, with Shade, his heart, his suit, his skin, his alter-ego Hades, and others all forming, taking control, leaving, and rejoining the hero.
* ''Franchise/SpiderMan'' has the Green Goblin, who sometimes suffers from this, though in an inversion the real persona ComicBook/NormanOsborn can be just as evil as his SuperpoweredEvilSide. Also The Lizard, who is Bruce Banner-lite.
** ComicBook/DoctorOctopus sometimes showed signs of this in his career. There were times when his original, timid, benevolent personality of Otto Octavius would resurface, but his evil Doctor Octopus persona would always return. (In the movie ''Film/SpiderMan2'' this Trope seemed to apply even more.)
* There is a ''StarWars'' comic, where after a Jedi kills a love in a fit of jealousy, she develops a dissociative disorder. One personality is a crazed killer, murdering women that remind her of the one her love was cheating on her with, while the normal personality obsessively "chases" this killer.
* ''Comicbook/XMen'': Similar to Crazy Jane, Professor X's son Legion originally possessed three personalities with a distinct psychic power (one was telekinetic, one was telepathic, one was pyrokinetic). This was later expanded to an unnamed number of personalities -- possibly thousands -- ALL with a unique power. Unfortunately, when these personalities were successfully merged, the new, improved Legion decided the best thing to do was to travel back in time to kill Magneto (he missed, killing his own father and [[ForWantOfANail unintentionally spawning]] the ComicBook/AgeOfApocalypse timeline).
%% * There's one story by German comic writer Walter Moers with a [[FunnySchizophrenia "schizophrenic"]] guy who says that he "counts for two" because of his two personalities, of which he is aware, and who switch pretty fast. One of them is pretty boring and essentially just says things like "me too". Yes, it's neither correct nor PC.

[[folder:Fan Works]]
%%% Please have the following examples listed alphabetically by original series and then alphabetically by individual/series title, if there are other entries. Also, please list both the title and the series it was based on.
* ''Fanfic/SomebodyThatIUsedToKnow'': an exceptionally dark example with [[spoiler: Matt Engarde, who vanishes for a month at the start of the story, and reappears with no explanation of where he went or what happened to him. In that time period, he seems to have developed a whole new personality, one who is deeply suspicious of everyone and has increasingly dangerous sociopathic tendencies; occasionally, however, brief glimpses of his old personality come through, either to cry about his situation, or to try to warn his old friend/lover about things that his new personality is planning to do or has already done. The thing that adds an extra dark twist to all of this is that it suggests that the persona you see Matt present in the game--the vague, cute, airheaded side that you see before the reveal--is an entirely fake persona made up by the new sociopathic one; the fake persona is sort of a shallow mockery of his original personality, which seems to have entirely vanished by the end of the story.]]
* North Korea OC characters in ''Webcomic/AxisPowersHetalia'' fandom tend to be either this or the EvilTwin of the canonical South Korea. This trope often comes into play in fics dealing with civil war.
* The whole point of ''[[http://www.tthfanfic.org/Series-722 Have Faith]]'', a series of crossover {{fanfic}}s by Mediancat, wherein Faith of ''Series/BuffyTheVampireSlayer'' discovers SHE is a split personality, created when her original self discovered the dead bodies of her father and sister, and then witnessed the slaying of her mother by the same one responsible. Her original self is none other than [[spoiler:[[WesternAnimation/{{Daria}} Daria Morgendorffer]]]]. Fortunately, the two personalities get along well (and even discover a ''third'' personality, an echo of Buffy Summers left over from when Faith and Buffy switched bodies after Faith woke from her coma in the two-part episode ''This Year's Girl'' / ''Who Are You''), to the point where [[spoiler:Daria]] is willing to go to extreme lengths to keep Faith alive, despite the wishes of her surviving family (her mother's sisters). [[spoiler:The second story ultimately ends in a SplitPersonalityMerge of all three personalities into a fourth, known as Daria Faith Morgandorffer, who is more than the sum of her parts and is the protagonist of the third and fourth stories.]]
* Some ''Film/CaptainAmericaTheWinterSoldier'' fics depict the Winter Soldier as a personality separate from the 'real' Bucky Barnes. Special mention goes to ''[[http://archiveofourown.org/series/118750 Ipseity]]'', which gives Bucky ''four'' personalities: in addition to the original Bucky and the nameless HYDRA assassin, there's the German prisoner "Axel" who's the best of them at making plans and the Russian patriot "Yasha" who's the most innocent and childlike of them -- and all of them are fully aware of and cooperative with one another.
%%%* [[spoiler:Fiona]] from FanFic/KiraIsJustice.
* What [[UnreliableNarrator Kali]] believes Kira is in the Death Note fanfiction, [[http://www.fanfiction.net/s/9644493/1/Zenith-Darkness-Reverie Zenith, Darkness, Reverie]]. Considering the author's knowledge of DID and MPD, and the lack of distinctive traits of either, it's quite possible that [[SuperpoweredEvilSide Kira]] is [[NightmareFuel something else entirely]].
* Harry is sorted into Ravenclaw in ''FanFic/HarryPotterAndTheMethodsOfRationality'', but has a number of 'personalities' for each of the other three houses. Harry isn't implied to be mentally ill exactly: the personalities are his own imagination and/or part of his reasoning process, not truly separate characters. They mostly come up to add interesting comments, like when 'Hufflepuff' jokingly suggests that Harry get over his temporary fear of accidentally eating something sentient (developed after he learns that it's possible to speak to snakes) by suggesting he eat the fellow students instead. After all, their sentience isn't in question.
** Harry also worries that he has a 'dark' side that he must control. He often thinks of his Dark side as something more akin to an alternate personality that he can choose to allow to 'take control' but must be afraid of.
* Several Literature/HarryPotter fics involve Harry suffering from non-canonical more extreme Dursley abuse and developing split personalities as a result, sometimes with later personalities emerging due to the various traumatic events at Hogwarts. In one story, it was ''Voldemort'' who had the split personality, and after a psychiatrist/Death Eater got his psycho personality to go into "hibernation", he became Harry's mentor and supported him in his dreams of becoming an Auror, while in a similar story the Voldemort persona was the result of an experiment in ''creating'' split personalities that was backed by Dumbledore.
* [[http://www.fanfiction.net/s/4749737/1/Somebody_Told_Me This]] {{A|lternateUniverse}}U KingdomHearts fanfic portrays Sora, Roxas, and Naminé as three sides of the same coin, with Sora as the "original". The summary splits them even further, which is confusing. So far the story revolves around Naminé's relationship with her LoveInterest, Marluxia, and him trying to get used to Sora and Roxas.
* In ''FanFic/MegaManReawakened'', Gemini Man has one that's similar to Two-Face.
* ''Fanfic/TheBridge'': After suffering the massive trauma plus psychic backlash from his wife Controller 011's death, Praetorian Guard 094's mind fractured into two. Monster X has his personality and mannerisms but no memories. Kaizer Ghidorah has his memories but has gone completely berserk and insane with rage.
* ''FanFic/TheImmortalGame'': After Twilight Sparkle is freed from the [[ArtifactOfDoom Sliver of Darkness]], the trauma of everything that's happened causes her mind to split in two -- the ActualPacifist Sparkle (the dominant mind) and the more brutish Twilight (who talks to her, but has no control over their body). This lasts until [[spoiler:her torture at [[BigBad Titan]]'s hooves causes her personalities to [[SplitPersonalityMerge fuse back together]]]].
* ''Fanfic/PinkiePersonalities'', a ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' fanfic, reveals that Pinkie has three distinct personalities, all of whom can talk freely in their shared mind, as well as switching who's in charge of the body (the one in control must willingly give up control though; the others can't forcibly take over). The original Pinkie thinks of the other two - the more playful Surprise (born from the conflict between boring monotony and the sudden, overwhelming happiness when she saw the Sonic Rainboom and the events that followed) and the more serious Pinkamena (born to shield Pinkie and Surprise from the pain and suffering they were being put through by an unscrupulous psychiatrist) - as her closest friends, and it helps that due to Pinkie's brain being wired differently, Surprise and Pinkamena are more balanced than most split personalities (Pinkamena suspects the reason is that they have access to a full range of emotions rather than just one or two each). While her Ponyville friends are more than a little surprised when they initially find out, they quickly come to accept the situation, since the doctors and Pinkie's own family have long since accepted that the two exist and aren't dangerous to her or anypony else.
* ''FanFic/PonyPOVSeries'':
** Pinkie Pie had several created by her refusal to accept certain parts of her. Pinkie Pie (the "normal" personality), Pinkamena (the personality she created to take any sad or unpleasent things she doesn't want to feel), Diane (the part of her who loves her biological parents and her home), and Pinky (her childhood memories). The trauma Discord put her through resulted in the birth of Angry Pie (an AxCrazy psychopath representing her repressed anger) that tried to ''eat'' her other personalities. [[spoiler:Pinkie performs a SplitPersonalityMerge, becoming one still wacky but ''far'' more sane Pinkie Pie.]].
** [[spoiler:Her [[BadFuture Dark World]] self, Angry Pie, brute-forced her mind back together, resulting in her mental self looking like a poorly sewn together ragdoll. After stealing Twilight's Element of Magic, it begins to awaken her old memories. Twilight then nearly kills her while almost going [[SuperpoweredEvilSide Nightmare]], and then Twilight (once she's talked down and gets back to her old self) uses a reverse version of the Memory Spell (showing Pinkie Twilight's memories instead of her own) to destroy Discord's taint. The combination of all this causes her mind to break apart again into Motherly Pie (her [[MamaBear motherly side]] who wants to take Discord's DealWithTheDevil to resurrect her adopted foals), Friendly Pie (the part of her who still loves her friends and wants to protect them), Guilty Pie (the part of her who is [[MyGodWhatHaveIDone guilt-ridden by what she's done for the last thousand years]]), and Lost Pinkie (her memories of the Lost Age that was erased in a CosmicRetcon). Twilight [[JourneyToTheCenterOfTheMind goes into her mind]] and has to convince the personalities to [[SplitPersonalityMerge merge back together]], resulting in a sane Pinkie Pie who's able to [[HeelFaceTurn redeem herself.]]]]
** Fluttershy and Fluttercruel: Fluttercruel is her own individual being with her own soul, they're just SharingABody. [[spoiler:However, Fluttershy actually has a split personality in the form of Flutterage, born from her repressed anger. In the end, she also does a SplitPersonalityMerge and becomes whole.]]
* It is eventually revealed in the ''Blog/ReadingRainbowverse'' that Octavia's sister is actually her split personality.
* Sombra from ''Blog/AskKingSombra'': One is a JerkWithAHeartOfGold, the other (called "Uber" or "Buttface" by Sombra) cares nothing about anyone.
%%* ''Roleplay/EquestriaChronicles'': Wishing Star was recently reveled to have this in the form of Dark Star.
* A very realistic example crops up in ''Fanfic/NobodyDies'', being very much PlayedForDrama when TheReveal happens. [[spoiler:It's Asuka, who in this fic has been subjected to an appalling level of emotional abuse by her mother.]]
* In ''Fanfic/ScarTissue'', Shinji ends up with one [[spoiler: that is a manifestation of his [[EndOfTheWorldAsWeKnowIt grief]] and [[ItsAllMyFault self-blame]] which he calls "the Beast".]] [[spoiler: Until [[CrowningMomentOfAwesome he overcame it]] in Chapter Fourteen, it enjoyed giving him nightmares about Third Impact and taunting him about his [[ILoveTheDead secret fantasies.]]]]
* Butters in the South Park fic ''Fanfic/TheMysterionMythos''. He regularly switches forms between his regular self, who is pretty much the same old Butters, Professor Chaos, who is the darker side of Butters, and Marjorine, an outgoing, flirtatious female ego.
* A RanmaOneHalf story called ''[[http://jusenkyo.wikia.com/wiki/A_Stained_Glass_Mind A Stained Glass Mind]]'' has Ranma as having one of these, even calling it a Tribe of One, which is a ShoutOut to a series of books set in the ''TabletopGame/DarkSun'' game setting.
* Cinder in ''FanFic/TheRWBYLoops'' eventually develops one when her internal conflict between EvilFeelsGood and GoodFeelsGood is unwittingly pressed by Ruby Rose. Interestingly, it is implied that while the two personalities are unaware of each other on a conscious level, they can communicate on a subconscious level; [[spoiler:it's all but stated that the good personality was actively sabotaging the bad one when she tried to destroy reality, leading to a number of VillainBall level mistakes and their eventual SplitPersonalityMerge]].
* In ''WesternAnimation/TheLoudHouse'' fandom, the idea of this trope explaining how Luan can flip between her normal lame pun-spewing but overall sweet self and her April Fool's day persona, which has been characterized as a psycho by many fans, is slowly gaining speed. Some authors even have the personality having come about because of [[KidsAreCruel bullies]] (possibly even as a defense mechanism) only to turn its sights and Luan's anger over the bullying [[MisplacedRetribution onto her innocent family]]. Generally, when this is the case, Luan [[MyGodWhatHaveIDone is horrified when she finds out her "harmless" pranks have put her family in danger]].
* In the ''Super Smash Bros'' fic trilogy ''Fanfic/{{Flinch}}'', Sheik is a split personality of Zelda. She's a PsychoForHire while Zelda is an ActualPacifist. Zelda is a terrible fighter and often relies on Sheik to win, though they dislike each other. Zelda eventually locks Sheik away [[spoiler:only for Sheik to come out later. Zelda regrets it but later comes to terms with her own aggressive side in a way that borders on a SplitPersonalityMerge.]]

[[folder:Films -- Live-Action]]
* In ''Film/{{Adaptation}}'', Donald Kaufman writes a script titled ''The Three'', in which the serial killer, the cop chasing him, and the victim the cop falls in love with are all the same person. His brother Charlie points out [[StylisticSuck how idiotic and filled with]] FridgeLogic the film is.
* ''Film/BlackSwan'' is clearly meant to make the viewer think this is going on, but it ultimately [[MindScrew leaves it ambiguous]] as to whether [[spoiler:Nina]] has a split personality or not; the case could be made either way.
* ''Film/TheDarkCrystal'' pushes the JekyllAndHyde trope to extremes when the [=urSkeks=], in an attempt to purge all evil from their nature, split themselves into the very, very good (but largely helpless) Mystics and the evil and proactively murderous Skeksis. They get better.
* Surprisingly averted with Two-Face in ''Film/TheDarkKnight''. Several other diagnoses can surely be made. For one, he still likes to make simple moral decisions based on a coin flip, and acts... should we say, chaotically. He uses the coin when deciding the fates of the people he holds responsible for everything that happened to him in the last day or so. He's on a revenge spree, using the coin to illustrate the arbitrariness of it all.
* The British horror movie ''Film/DeadOfNight'' has one story about a ventriloquist, Maxwell Frere (Creator/MichaelRedgrave), who believes that his [[DemonicDummy dummy, Hugo, is alive]] and wants to leave him for another ventriloquist. The truth is [[AlternativeCharacterInterpretation open to interpretation]], but Redgrave's performance strongly implies that Hugo is Maxwell's split personality, as there are shots where Maxwell's lips are moving even when it's "Hugo" who is talking.
* The TwistEnding of ''Film/DressedToKill'' reveals that [[spoiler:Dr. Elliott inhabits an alter-ego, the murderous transsexual Bobbi.]]
%%* ''Film/FightClub'' [[spoiler:made this its most ingenious [[TomatoInTheMirror twist]].]]
%%%* Pamela Voorhees in ''Film/FridayThe13th1980''
* One of the protagonists in the Russian comedy ''Gun with a Silencer'' "becomes" a woman between midnight and noon. One hilarious scene involves "her" being examined by a gynecologist, who takes one look at the plumbing, [[INeedAFreakingDrink drinks a shot of vodka]], and says "she's healthy".
%%%* Chris Falkowski's short film, ''[[http://www.vimeo.com/15013204 Head]]''.
* In ''Film/HideAndSeek'', David tries to figure out who his daughter's imaginary friend, Charlie, is. TheReveal shows that [[spoiler:David is Charlie, and Charlie was the one who murdered his wife.]]
* ''Film/{{Identity}}'' [[spoiler:has a plot twist revealing that the characters are all split personalities in a BattleInTheCenterOfTheMind]].
* Gollum and Sméagol ("Stinker" and "Slinker") from Peter Jackson's ''Film/TheLordOfTheRings'' live-action movies. The two personalities frequently carry on conversations, to the point that they're practically two minds consciously coexisting simultaneously in the same head. This split-personality theme is less pronounced in the earlier animated movies and the original books, but still present. See entry under GollumMadeMeDoIt.
* Brazilian movie ''Loucas pra Casar'' has Maria Lúcia, a woman with long-lasting marriage obsession, finding out her boyfriend has two lovers, exotic dancer Lúcia and overtly religious younger woman Maria. Then at the altar she finds out [[TheThreeFacesofEve all three]] were her - Maria Lúcia and her partner liked to act out sexual fantasies, but she became LostInCharacter.
* ''Film/TheMachinist'', which is ''sort of'' a deconstruction of both ''Film/FightClub'' and ''Literature/CrimeAndPunishment'', explores the psychological side of this and the kind of trauma that can cause it.
%%% * [[spoiler: Clark Stevens]] from ''{{Film/Madhouse2004}}''
* The Farrelly Brothers' movie ''Film/MeMyselfAndIrene'' is about a mild-mannered cop who is routinely abused, leading him to eventually flip out and become a jerk.
* [[spoiler:Axel Palmer]], the killer in the original ''Film/MyBloodyValentine''.
* [[spoiler:Tom Hanniger]], the real killer in ''Film/MyBloodyValentine3D''.
* In the movie ''Peacock'', the painfully shy John (Creator/CillianMurphy) has a more confident personality named Emma who makes him breakfast and lays out his clothes every day, like a wife would -- which is precisely what everyone thinks she is when she is accidentally discovered. The personalities are aware of one another, but they have no memory of the other's experiences. John gets increasingly panicked as Emma begins to 'control' him more, and [[spoiler:Emma eventually 'murders' John by staging his death and presenting as Emma only.]]
* In [[TheFilmOfTheBook the movie]] ''Film/PrimalFear'', the shy and gentle Aaron, on trial for killing the archbishop, is revealed to have a split personality named Roy who is much more outspoken and aggressive and did in fact kill the clergyman. At the end, we find out that [[spoiler:Aaron doesn't actually have a split personality; the more disturbing truth is that ''Roy'' created ''Aaron'' and has been hiding behind the fake personality for years.]]
%%% * ''Film/{{Psycho}}''.
* In ''Film/PsychoBeachParty'' you learn very early on that Chicklet has at least two other personalities.
* Carter in ''Film/RaisingCain'' has several, including the amoral Cain and his "fall guy" Josh.
* Played for laughs in ''Film/{{Serenity}}'' where Simon briefly suspects that the mysterious "Miranda" could be an alternate personality of River (as it turns out, Miranda isn't a person at all). A couple of seconds after he raises the possibility, both of them burst out laughing at how ridiculous and cliched it would be.
* ''Film/{{Sybil}}'', based on the 'true story' of Shirley Ardell Mason.
* ''Film/TheThreeFacesOfEve'' is about a timid housewife named Eve White who learns that her splitting headaches and blackouts are the result of having developed a wilder and more free-spirited personality named Eve Black. A more neutral third personality who calls herself just "Jane" eventually emerges too. [[spoiler:The film ends with Jane becoming the dominant and sole personality.]]
** After this film was released, the number of Americans diagnosed with [=MPD/DID=] increased quite dramatically; this rash of [[FollowTheLeader copycats]] causes part of the skepticism surrounding the disorder's existence.
* By Nick's choosing in ''Film/YouthInRevolt''.
* ''Film/{{Split}}'' concerns a man with 23 different personalities, three of which are conspiring to summon a 24th.

[[folder:Light Novels]]
* Shizuku from ''[[Anime/YukiYunaIsAHero Kusunoki Mebuki is a Hero]]'' has a split personality caused by child abuse from her parents. She's usually very quiet, but when in danger her outspoken berserker SHIZUKU personality comes out.
* Suzuho in ''LightNovel/MagiciansAcademy'' is usually quiet and meek, communicating only through [[TalkingWithSigns sketchbook messages]]. When she removes her ribbon, her other side comes out, which is the exact opposite in personality. Violent, talkative, and, for some reason, blue-haired.
* In ''LightNovel/{{Sukisho}}'', [[spoiler:both Sora and Sunao developed split personalities, Yoru and Ran respectively, due to experiences they were subjected to as children. The catch: the split personalities Yoru and Ran have a romantic relationship...unlike Sora and Sunao. Every now and then the split personalities will take over and some, or, depending on the degree of the situation, extreme awkwardness follows.]]

* The [=AIs=] in ''Literature/AncillaryJustice'' have a mild version of this. While [[HiveMind ancillaries share a single identity]], each body retains its individual emotions so they don't get trapped in endless loops of logic or give undue attention to pointless details. An individual ancillary's feelings toward a person can color the whole AI's perception of that person and affect its behavior, since the ancillaries all share one mind. If they decide they don't like you, they can make your life inexplicably uncomfortable, and Amaat help you if you [[MamaBear hurt someone they like]]. [[spoiler:[[TheEmperor Anaander Mianaai]] is a straighter example as well.]]
* In one ''Literature/{{Animorphs}}'' novel, ''The Separation'', Rachel's personality goes so far as to be split into two physically different people -- one timid, gentle, and pacifistic; the other ruthless, violent, and obsessive -- when she gets cut in half while in starfish morph. Because of starfish's regenerative powers, she "grows back" a ''whole extra person.''
* Most ''Literature/{{Aristoi}}'' cultivate multiple "daimones" to help them multitask. %% It would help to describe what daimones are in this context.
* In ''Literature/ArtemisFowl'', [[spoiler:Artemis]] gets one because of [[spoiler:his Atlantis Complex]].
* Margaret Millar's Edgar-award winning thriller ''Beast In View'', in which a woman who is apparently the victim of a malevolent stalker turns out to be being persecuted by her own malevolent alternate personality, is the UrExample in the crime genre of the "the villain is actually the hero's or [=PoV=] character's evil alternate" idea. Unfortunately, it later became a groanworthy cliche due to simplistic and/or logistically impossible examples.
* ''Beyond Bedlam'' by Wyman Guin depicts a society about 1000 years in the future where everyone is "schizophrenic" (actually, possessed of two personalities; "schizophrenia" rather than "multiple personality disorder" being the accepted medical term in TheFifties) and each of the two personalities is allowed five days of life at a time, before being legally required to surrender the reins to the other personality.
* Subverted in ''Literature/{{Blindsight}}'': one of the characters is a linguist with ''three'' surgically-induced alter personalities (known collectively as the Gang of Four). Some time is taken up in discussion of twentieth-century attitudes towards MPD, which are largely dismissed as barbaric and irrational. The Gang are a relatively realistic depiction of D.I.D cases where all of the personalities know of the others' existence and cooperate.
** In the sequel, ''Literature/{{Echopraxia}}'' it turns out that [[spoiler: vampires are outright {{Mind Hive}}s, and Valerie bypassed the crucifix glitch by sacrificing one of her parallel processes. Similar to the 20th cen hypothesis of D.I.D. that the Gang dismissed as "irrational". Though they did exist before the trauma and vampires are complete sociopaths.]]
* In Creator/JackVance's ''[[Literature/TheDemonPrinces The Book of Dreams]]'', Howard Alan Treesong, the last Demon Prince, has five separate personalities.
* Severian in The ''Literature/BookOfTheNewSun'', who is both the original torturer Severian and also Chatelaine Thecla after eating the Albazo (and Thecla.)
* Happens to some of the Clayborn in David Wingrove's ''Literature/ChungKuo'' series when under severe pressure.
* In Creator/StephenKing's ''Franchise/TheDarkTower'' series introduces two characters in [[Literature/TheDrawingOfTheThree the second book]]: Odetta Holmes, a fairly well-to-do black woman who lost her legs and is generally surviving the 1960's as best she can; and Detta Walker, who is dangerous, brutal, and very bitter. The two personalities are almost completely unaware of each other, at least until the plot comes knocking. [[spoiler:At the book's climax, the two personalities integrate into Susannah Dean, who possesses the good sense of the former, and the tenacity and will of the latter]]. Odetta/Dedda is often referred to as "schizophrenic," which is {{justified}} in this case as most of the characters' information on the disorder comes at second- or third-hand from Eddie's recollections of [=80s=] pop culture.
%%%* Sefalet's right and left-hand mouths in ''Literature/DirgeForPresterJohn''.
* Altogether Andrews, from Creator/TerryPratchett's ''Literature/{{Discworld}}'' series, has ''eight'' personalities, none of which answer to Andrews. There's also Agnes Nitt and her alter ego [[AwesomeMcCoolName Perdita X. Dream]], which started out as a name she thought was cool in ''Discworld/LordsAndLadies'', then became the embodiment of her id in ''Discworld/{{Maskerade}}'', then became a full-on SplitPersonality in ''Discworld/CarpeJugulum''.
** This is apparently not that uncommon on the Discworld. Perdita is explained as having come about specifically because Agnes took a part of herself -- her desire to not be a nice girl with a good personality -- and gave it a name. Her senior witches muse to themselves that giving something a name gives it life, too. Rincewind's conscience and Sam Vimes's inner rage are also sometimes depicted as semi-sentient, especially in ''Night Watch'', where Vimes refers to it as "The Beast". In ''Thud!'', we find Vimes also has an "inner watchman", who [[spoiler:ends up [[HeroicWillpower kicking a powerful vengeance spirit out of Vimes' mind.]]]]
** Mightily Oates also suffers from this, dividing into a skeptic part and a devout part. At one point, he considered having himself exorcized. And, like Agnes/Perdita, he is resistant to vampiric mind control, because they can control only one mind per brain.
** ''Discworld/{{Thud}}!'' also features Pointer and Pickles, the owners of a rock collector's shop, who turn out to be the split personalities of the same woman.
* In ''Literature/EdenGreen'', humans infected with the needle symbiote eventually develop a second, psychotic, survival-oriented personality capable of performing horrible deeds that the original human could.
* Janis Cordelia Plumtree in ''Literature/EarthquakeWeather'' by Creator/TimPowers, whose condition is complicated by the fact that [[spoiler:one of her personalities is actually the spirit of her dead father]].
* In the two part ''Literature/FearStreet'' story ''Fear Hall'', it turns out that [[spoiler:Hope Mathis' three friends, Jasmine, Angel, and Eden, as well as her homicidal boyfriend Darryl are actually split personalities, created due to her mother's abusive treatment towards her.]]
%%%* ''Literature/TheFifthSally''
* [[spoiler:This is the big twist]] of ''Literature/FightClub''. About 2/3 through the book, the reader [[spoiler:and the narrator find out that Tyler is the Narrator.]]
* Used as a MindScrew in ''Literature/{{Ghoul}}'' by Creator/MichaelSlade. The BigBad of the novel, [[spoiler: Saxon Hyde]] comes from an "old money" family where madness runs in the genes. The villain's DID is the result of childhood sexual abuse, ''however'' upon another traumatic event, the villain suffers a complete break with reality and it becomes [[ItMakesSenseInContext full-blown paranoid schizophrenia.]] A veritable grab-bag of crazies, all in one character.
* In ''Literature/TheHeroesOfOlympus'', the conflict between the Roman and Greek camps causes some serious issues for the gods, since there are equal calls for their Roman and Greek sides. This causes the sides to battle for dominance, the consequences of which vary in severity depending on how different the Roman and Greek aspects are. Gods like Aphrodite/Venus or Nemesis walk off scot-free, since the ideas of love and revenge are the same in Greece and Rome. Hercules/Heracles gets headaches, but otherwise it isn't too bad. Athena/Minerva is reduced to a scatter-brained wreck and Dionysus/Bacchus can't remember Percy and gets a blinding headache when Percy calls him Dionysus instead of Bacchus. The issue is apparently grave enough for them to be rendered incapable of dealing with other problems until the issue is resolved.
* Ellen Hopkins' ''Identical'' has a more realistic case of this. Near the end, it is revealed that [[spoiler:Kaeleigh has DID and Raeanne is her other personality. The real Raeanne died in a car accident during the twins' childhood.]]
* {{Averted}} in Geoph Essex's ''Jackrabbit Messiah'': Jack has [[ShownTheirWork schizophrenia]], not [[HollywoodPsych DID]], though the end result is that he plays [[OddCouple Oscar Madison to the Felix Unger]] living inside his head, suggesting similarities to the favorite sort of fictional split personality (especially during a [[LiteralSplitPersonality more surrealistic portion of the climax]]).
* Literature/JoeLedger has a committee in his head: [[OnlySaneMan the Civilian]], who keeps him sane but is unable to deal with his day job; [[BloodKnight the Warrior]], who just wants to hurt someone; and the Cop, who combines the best of both, being honorable but still a fighter.
* The titular Dragonlords from ''The Last Dragonlord'' are born with two souls/identities: one human and one dragon. This overlaps into SharingABody in that the two personalities are fully aware of each other and converse at times. The main character, Linden, has trouble controlling [[GollumMadeMeDoIt the anger issues]] of his dragon side, Rathan. His mate's infant-like dragon side refuses to acknowledge her.
%%%* [[spoiler:Holmes/Moriarty/Jack the Ripper]] in ''Literature/TheLastSherlockHolmesStory''.
* In ''Literature/TheLordOfTheRings'' and related materials, it is suggested that [[GollumMadeMeDoIt Gollum's personality]] developed from Sméagol talking to the Ring ("my precious") which he eventually identified as part of himself, as well as his desire to place the blame for the murder of his friend Déagol onto someone else.
** Gollum's split personality never appeared in the first edition of ''Literature/TheHobbit'': it only shows up first in the {{rewrite}}, when Bilbo hears them discussing after realizing that Bilbo had the Ring all along. At the time of writing the first edition, the Ring wasn't evil yet in Tolkien's mind, and so had no reason to poison Sméagol's mind.
* ''Literature/TheMindsOfBillyMilligan'' is the true story of a man with multiple personalities.
* In the ''Literature/NewJediOrder'' series, teen Jedi [[ActionGirl Tahiri]] has this after a [[MadScientist Shaper's]] attempt to transform her into a Force-using [[ScaryDogmaticAliens Yuuzhan Vong]] fails -- Tahiri retains her original personality, but the Vong personality can't be excised and remains in her subconscious. Ultimately, Riina (Tahiri's Vong half) tries to pull a SplitPersonalityTakeover, but when she and human Tahiri prove too connected for this to work out, a SplitPersonalityMerge happens instead. The resulting person calls herself Tahiri, but has the memories and experiences of both.
* In Amelia Atwater-Rhodes' ''Persistence of Memory'', Erin suffers from DID with the complication that [[spoiler:her alter comes from psychic residue from a vampire attack on her pregnant mother. While the alter that manifests is just the psychic remnant, the basis for Erin's alter, Shevaun, is a very real and very dangerous vampire.]]
* In Creator/JamesSwallow's ''TabletopGame/{{Warhammer 40000}}'': ''[[Literature/BloodAngels Red Fury]]'', the BloodMagic gives the Bloodfiends the GeneticMemory of all those whose blood they drank, giving them effective multiple unintegrated personalities -- and a fierce desire to drink more blood, worsening the problem. Rafen, fighting one, can clearly [[WasOnceAMan recognize the source of its blood]], and {{dying|AsYourself}}, it might have said, "Brother."
* Done in a fairly realistic way in Matt Ruff's ''Literature/SetThisHouseInOrder'' with two characters who both have DID. Both suffered severe abuse as children, but one has been aware of this problem for a long time, and all the personalities work together and see a psychiatrist. The other character is younger and less aware of what is going on, and is afraid because she keeps having periods of memory loss. Both characters eventually work towards the goals of overcoming abuse, getting treatment, and choosing between full integration and trying to function by having all personalities cooperate with each other.
* Iliana Ghemor in the ''Literature/StarTrekDeepSpaceNineRelaunch''. She was implanted with the memories and personality of Kira Nerys as part of an undercover operation. Now, she has both her original memories and Kira's, and considers herself the rightful inheritor to the real Kira's life. Because Kira set the bomb which killed Iliana's betrothed during the Occupation of Bajor, she also has a split perspective on his death -- as both the guilty party and a victim.
* OlderThanRadio: In the classic Robert Louis Stevenson novel ''Literature/TheStrangeCaseOfDrJekyllAndMrHyde'', Dr. Henry Jekyll develops a formula that separates his good and evil personalities. By drinking the potion, he can transform himself into the villainous Edward Hyde.
%%%* ''Sybil''
* Creator/SidneySheldon's novel ''Tell Me Your Dreams'' is about a woman who fears she is being stalked, and her two co-workers who become concerned about her. It is eventually revealed that all three are the same person; the main character developed two separate personalities because she could not handle the trauma of [[spoiler:childhood sexual abuse]].
* Ted Dekker's thriller novel ''Literature/Thr3e'' (as well as TheFilmOfTheBook): [[spoiler:The killer who's been chasing the protagonist is actually a split personality of the protagonist. But wait! Isn't the title "three"? That's right! It turns out his childhood friend who's been helping him solve the mystery is ''also'' one of his split personalities.]]
* The protagonist of Simon Hawke's ''Tribe of One'' trilogy (set in the ''TabletopGame/DarkSun'' setting of ''TabletopGame/DungeonsAndDragons'') is a man with more personalities than he can count, who [[WalkingTheEarth walks Athas]] in search of a way to bring his fractured mind together.
* In Creator/MichaelFlynn's ''[[Literature/SpiralArm Up Jim River]]'', Donovan. His multiple personalities were induced deliberately, but the manner was bungled -- also, perhaps, deliberately.
* In the Creator/MichaelSwanwick novel ''Vacuum Flowers'', Wyeth has deliberated installed four distinct personalities into his own mind, modeled after archetypes (he says it's based on the ideal makeup for an aboriginal hunting party). All of them are active simultaneously and seem to get along fine; in emergency situations, they all voluntarily step aside for the persona best able to handle that particular type of emergency, and in non-emergencies they make decisions by consensus. The heroine Rebel/Eucrasia is a straighter example; the body belongs to Eucrasia, but the personality in charge at the start is Rebel, who has been overlaid on top of Eucrasia due to an accident with some entertainment software.
* Creator/LoisMcMasterBujold's ''Literature/VorkosiganSaga'':
** Lord Mark Vorkosigan developed four extra personalities to resist torture: Gorge, Grunt, Howl, and Killer. While he learns to control them, they explicitly do not go away. Fortunately, they are all fixated from the get-go on protecting/aiding Mark to the best of their abilities and like his girlfriend.
** Mark's brother/progenitor Miles hovers upon the verge of this trope when his undercover identity of Admiral Naismith threatens to become a fully separate persona. Mark also laments that at least Miles' alter ego is the sort of person you can dress up and take out to a party if the need arises compared to his far more primal alters.
* ''Literature/TheWheelOfTime'':
** [[spoiler:Rand al'Thor and Lews Therin]] fit this trope as well as anything else. It's difficult to determine if it's caused by madness from use of the One Power or being a reincarnation of the original and the voice is actually a real being. In any case, [[spoiler:Rand]] certainly thinks he's suffering from madness. At the end of the 12th book, [[spoiler:they pull a SplitPersonalityMerge, after which it's explicitly stated that they 'aren't two men and never were' -- that is, Rand is most definitely the reincarnation of Lews Therin, and he also most definitely had some access to snippets of Lews Therin's memories and knowledge as a result, but the 'voice' of Lews Therin that Rand conversed with for six books was merely a symptom of his deteriorating mental state]].
** The series also includes a couple of weird borderline examples with the recurring villains [[AxCrazy Padan Fain]] and [[ProfessionalKiller Slayer]]. Fain merged imperfectly with the soul of the EvilChancellor Mordeth, and though he thinks of himself as one personality, he has two distinct sets of mannerisms which he'll switch between randomly and apparently unwittingly, and sometimes he'll forget which of the two names he's currently using. Slayer is actually two distinct men named Luc and Isam who share a body; they were combined into one by [[GodOfEvil the Dark One]], but retain discrete identities to the point that when which personality is dominant changes, the body also changes to reflect it.
* In ''When the Bough Breaks'' (part of Creator/MercedesLackey's ''[=SERRAted Edge=]'' series), a young girl develops multiple personalities when her father starts raping her. One personality takes over whenever she realizes a rape is about to occur, to protect the other personalities from knowing what's been going on.
* Mark Meadows, AKA "Captain Trips," of the ''Literature/WildCards'' series. Normally a smiling, weirdly dressed, and rather ineffectual hippy (albeit one with great skills in biochemistry), in time of need, his various powders and potions are capable of making him an ace of badass proportions... or rather, several aces, depending on which one he takes. All of them have a different mind and personality, and most of them think the good Captain is a wimp or worse, and do everything they can to keep from reverting when the chemical wears off.
* ''Literature/XWingSeries'': Wraith Squadron's "Runt" manages to skirt the reality issue by being, well, an alien - he has a number of highly specialized minds, such as the Pilot and the Student; this is noted to be natural and healthy for his species, and learning to switch quickly between personalities is helpful for him. Lara Notsil/Gara Petothel/Kirney Slane, though she might appear to fit the trope and once dreamed of her [[DoubleConsciousness different personae arguing]], is really a spy who started BecomingTheMask and soon had a [[HeelFaceTurn genuine desire to defect]], as well as some unstable identity issues. No split personality.
* ''Literature/{{Oathbringer}}'' (third book of ''Literature/TheStormlightArchive''): Shallan Davar falls into an downward spiral in this book, and keeps creating new personalities with her [[MasterOfIllusion Lightweaving]] to solve various problems. It started in ''Literature/WordsOfRadiance'' with the thief persona, Veil, then develops when she creates the warrior Brightness Radiant to handle using her Shardblade, and eventually ends up with either personality leaking out at unwanted moments. Soon she begins to consider "Shallan" as just another alternate personality. [[spoiler:Eventually, she is forced to come to terms the limits of her personalities when her actions eventually lead to the death of a young boy and that Veil isn't really as experienced as she pretends. This ends up with her uncertain and very confused of her self and her personalities constantly switch out with one another. In the final battle, we see things from all three's perspectives... and it's revealed that Shallan is just an illusion at the moment, and Radiant is the real one.]]

[[folder:Live-Action TV]]
* On ''Series/AllyMcBeal'', one client was the original personality, who wanted treatment to get rid of the alter-ego, who hired another firm to protect its existence. The court found in favour of the original personality, which the treatment then unexpectedly eliminated. This is wrong, as the treatment for DID is to integrate the personalities together.
* 1960's ''Series/{{Batman}}'' series. Professor William Omaha [=McElroy=], an Egyptologist at Yale University, would become the villain King Tut every time he was hit on the head and return to normal when he was hit on the head again. He became the only series villain never to be sent to jail, via the insanity defense.
** Prof. Mc Elroy also knew about his Tut self (despite not recalling ''what'' he did under it) and also tried to ''prevent'' King Tut's emergence via wearing a special hat supposed to soften blows to the head. Obviously, it didn't work.
* ''Series/{{Baywatch}}''. A woman develops a split personality when her twin sister dies. Her two personalities both become obsessed with Mitch Buchannon. One personality takes over and tries to drown him. The real topper is the woman is [[http://www.agonybooth.com/agonizer/Baywatch/Mirror__Mirror.aspx played by Carrie-Anne Moss]] years before ''Film/TheMatrix''.
* In the ''Series/{{Columbo}}'' episode ''Fade in to Murder,'' actor Ward Fowler (played by Creator/WilliamShatner) begins to demonstrate increasing signs of having a split personality with Detective Lucerne, the character he plays on the fictional TV show. While Fowler seeks to evade Columbo's investigation, Detective Lucerne actively aids the lieutenant in tracking down his other self.
* ''Series/CriminalMinds'' used this twice: once in the second season, when [[spoiler:Reid was kidnapped by a man with three personalities, one of whom tortured him, one of whom drugged him, and the last of whom played Russian roulette]], and once in the fourth season, when [[spoiler:the rapes and murders of young men in Florida over spring break turn out to be the work of a woman named Amanda in the body of a guy named Adam]]. In the first case, all of the personalities were aware of each other, although it's not clear that they knew they inhabited the same body. In the second, only the secondary personality is aware of the condition, which leads to a [[spoiler:SplitPersonalityTakeover]].
** Three times. In "All That Remains", Bruce Morrison is a friendly enough person, but has a sadistic personality named Johnny who tends to come out during drunken rages. Bonus points for this one coming right the hell out of ''nowhere'', whereas the others had some clues to them. [[spoiler:Interestingly, he isn't the killer. He isn't even involved.]]
* An episode of ''Series/{{CSI}}'' had a woman faking multiple personalities to get an insanity plea.
* In ''Series/CuteyHoneyTheLive'', Panther Claw member Yuji Nakajo has three split personalities: the original, a calm and reserved young man; Hikomaro, a gleefully sadistic child; and Giza, a viscous BloodKnight. [[spoiler:Later in the series, they are overtaken by a fourth personality: Hikaru, a non-combative yet ManipulativeBitch.]]
* The main hook of ''Do No Harm'': The title character is an ethical doctor who switches to a malevolent second personality at 8:25 pm each night and then reverts back at 8:25 am the following morning. After keeping this personality sedated with drugs for years, one day he finds that his body has become immune to them... unleashing the other personality, now bent on destroying his life. [[spoiler:[[SubvertedTrope Subverted]] in the series finale when it was [[TheReveal revealed]] that the benevolent personality was the alternate personality while the malevolent one was the original]].
* The ''Series/DoctorWho'' audio Omega has a sort-of case of this: [[spoiler:Omega, half of whose personality is under the delusion that he's the Doctor and that Omega isn't inhabiting the same body as he is.]] However, it's clearly not DID and has a more sci-fi cause.
* ''{{Series/Dollhouse}}'' has two: [[spoiler:Alpha and Echo. However, Echo only gets it the last two episodes, and they're both a literal case of many personalities.]]
* In ''Series/TheFollowing'', after recurring villain Luke Gray is killed, his twin brother/killing partner Mark recreates him as an alternate personality which he slips into to deal with stressful situations, as Luke had done for him in life.
* An episode of ''Series/ForeverKnight'' features a woman with two personalities, one of whom is a normal mortal and the other a vampire.
* In ''Series/{{Grimm}}'', there was a kid who was a [[DifferentlyPoweredIndividual wesen]] called a ''Genio innocuo'' who had his genome spliced with ''Löwen'' DNA and his Löwen side developed a separate personality of its own, killing people that he competed with as a way of protecting him.
* Rare realistic example from ''Series/{{Hannibal}}'', in which [[TheProfiler Will Graham]] begins to have dissociative episodes due to being overdosed on NightmareFuel. It basically consists entirely of stretches of "lost time," in which he can't remember what he's been doing.
* Niki Sanders on ''Series/{{Heroes}}'' has "Jessica", the personality of her dead sister, as an amoral alter ego with super-strength. Some people just can't handle having superpowers and the stress causes a dissociative break, making this one a quite literal SuperpoweredEvilSide.
** When "Jessica" kills their father in early S1, it's made clear that he was abusive to the point of killing Nikki's sister Jessica, after whom the alter ego is named. Only the "Jessica" alter remembers, which resembles real theories of DID fairly well. In S2, a third, party-girl personality called Gina, who apparently began as a mere alias, emerges.
* ''Series/{{Highlander}}'' had an immortal with a split personality. The good side, Michael Moore (no, not THAT one), was a good friend of Duncan's. But the evil side, Quentin Barnes, slowly overpowered Moore and Duncan had to keep his promise to stop Barnes. In an earlier time, the evil side actually killed the good side's girlfriend.
* ''Series/HillStreetBlues'' featured a murder at a homeless shelter for which the only witness was someone with this condition, or something like it. Eventually it transpires that one of the man's personalities was the killer, and when he figures that out [[DrivenToSuicide he throws himself out of a fourth-storey window]], [[TakingYouWithMe determined to prevent "TJ" (the killer) from harming anyone else.]] It's as much of a TearJerker as it sounds.
* On the British soap opera ''Series/{{Hollyoaks}}'', troubled emo kid Newt has an alternate personality called "Eli", who trashes the Deans' house and encourages him to run away from his foster home. In later episodes, he plans to find and kill the real Eli (a friend from his days in the social care system) in the hope of banishing the "Eli" personality.
* In the third season of ''Series/HomicideLifeOnTheStreet'', a serial killer turns out to have multiple personalities, including [[spoiler:a seven-year-old girl. One detective tricks this personality into burning herself, so another personality sues the precinct. However, it is implied that this may all be a ruse on the killer's part.]]
* ''Series/JamAndJerusalem'' has Rosie, the awkward but friendly CloudCuckooLander, and her angry, intimidating alter-ego Margaret.
** This becomes much more poignant in the second series when it is revealed that Rosie was [[spoiler:molested as a child]]; multiple personalities are common among [[spoiler:trauma survivors]], so this may be a possible explanation for Margaret.
* Korean drama ''Kill me heal me'' features the main character with [[spoiler:7]] different personalities due to his experience as a child.
* The Season Nine finale of ''Series/LawAndOrderCriminalIntent'', "Three In One", has a character who legitimately has three personalities as opposed to faking. The following spoiler will tell you whether any of them did anything illegal. [[spoiler:Yes. He ended up that way because of severe childhood abuse, which his female abuser told him was "discipline". When he grew up, hearing any adult woman talk about the importance of disciplining a child made him remember his own "discipline", which made him angry and afraid and brought the "protector" personality to the surface. The protector would then attack and kill the woman, whom he believed was advocating and participating in the abuse of children.]]
* ''Series/LawAndOrderSpecialVictimsUnit'' has had a multiple personality woman (Cynthia Nixon) killing her abusive dad. [[spoiler:She gets a "not guilty" verdict by reason of insanity, but she was faking it. The detectives realize it too late, and settle for arresting her sister, who was also involved.]]
* An episode of ''Series/LieToMe'' has Cal take a client with this disorder. Cal has to figure out which of her several personalities witnessed a murder. Although the character is initially referred to as having a split personality, Foster corrects the speaker and instead says that she has DID, which is the term used for the rest of the episode. Foster also [[LampshadeHanging notes that DID is very rare, assuming it exists at all.]]
-->'''Foster:''' It's Dissociative Identity Disorder, and it's more plausible than a psychic vision, but just barely.
* By the end of season 4 of ''Series/MelrosePlace'', Kimberly had several personalities. %% Would be useful to add examples here, please and thank you.
* On ''Series/MrRobot'', [[spoiler: it is revealed that the titular Mr. Robot, a hacker who recruited Elliot into the hacker collective fsociety, is actually another personality of Elliot that manifests itself as a hallucination of Elliot's deceased father. Elliot is not aware of this until near the end of the season.]]
* ''Series/MurdochMysteries'' features a suspect in a murder that suffers from this in the episode "Me, Myself, and Murdoch".
* ''Series/MyOwnWorstEnemy'' has this as the premise of the show. Edward Albright, a spy, is the original personality, and Henry Spivey, a quiet middle-management office employee with a wife and two kids, is the implanted cover. The chip that separates the two lives breaks down, and Henry becomes aware of his alter-ego.
* ''Series/NCISNewOrleans'': The killer in [[spoiler:Episode six]] is revealed to be one of these, [[spoiler:born to shield his original from their abusive father. He framed the father for a crime he didn't commit in order to get him locked up; when the father was released, the [[JekyllAndHyde Hyde]] personality started killing again to frame their father a second time and get him sent back to jail permanently.]]
* Played for laughs in an episode of ''Series/NightCourt'', where a defendant's DID wasn't revealed to the main characters until near the end. One personality was prudish, the other was slutty. The episode's running gag was for her more "open" side luring [[HandsomeLech Dan]] into some private (and always off-camera) location for some hanky-panky, only for her prudish side to re-emerge just as things were apparently getting good.
* In the ''Series/NightVisions'' episode "Switch", the protagonist, Sydney, has multiple personalities.
* ''Series/NipTuck'': one of the episodes is Montana/Sassy/Justice. One wants her ankles fixed and another one wants her breasts gone because she is 5. This is the same person.
* While this is a staple trope of daytime soap operas, the soap ''Series/OneLifeToLive'' took this to an extreme. Not only did established character Victoria Lord Buchanan develop a number of personalities (the most notorious of which was streetwalker Niki Smith, a complete contrast to Viki's upper-crust manner), her daughter Jessica later developed her own split personality (tough girl Tess), as a result of a retcon where a young Jessica follows Niki to a bar and gets raped by a guy and this was caught on tape. Apparently, in the OLTL universe, split personality is a genetic disorder. In addition, Viki's brother, Todd Manning, at one point was also thought to suffer from DID, with 5 separate personalities: the original Todd, Tommy, a little boy who was the abused Todd as a small child, Rodd, an Italian-accented charmer, and Peter, a representation of Todd's abusive step-father, and a strict female personality that served as the Gatekeeper. At the end of the storyline, Todd admitted he'd been faking all of the personalities, but as he [[PutOnABus left town]] (the actor was leaving the show), a last scene showed Todd and all of his personalities on the plane.
* A patient in ''Series/PrivatePractice'' was alleged to have this condition; she was diagnosed at the age of seven and partially raised by her older sister, and she hasn't had a resurgence in ten years. Unfortunately, they came back with the stress of her sister moving away. [[spoiler:She was actually faking so that they won't move.]]
* Shawn and Gus run into a character with three personalities on ''Series/{{Psych}}''. [[spoiler:Two are male, one is a female, and one is the killer, who is (understandably) a little ticked off that the female personality is scheming to get a sex change.]] When Gus points out how rare the condition is, it is hand-waved by Shawn pointing out it only has to happen once to be true.
* ''Series/{{Sanctuary}}'' has Adam Worth, a genius with a split personality. It's a bit confusing, since both are, apparently, named Adam. The split started after [[spoiler:his daughter got sick and died]]. He blames the Five for this.
* An early episode of ''Series/StarTrekTheOriginalSeries'' pushes the JekyllAndHyde trope to extremes when Captain Kirk is divided into his good and evil halves. And again like ''The Dark Crystal'', Kirk's good half is weak and indecisive while the evil Kirk has his way with pretty much everyone (including, very nearly, Yeoman Rand). He gets better.
* In one episode of ''Series/StargateSG1'', Carter likens being host to a Tok'ra symbiote to having schizophrenia. They meant DID. Apparently, they later did their research, and as though to pay penance for their error, made an episode where Daniel Jackson actually got schizophrenia from an AppliedPhlebotinum that was intended to kill Goa'uld.
* In ''Series/TerminatorTheSarahConnorChronicles'' episode "Allison from Palmdale," [[RobotGirl Cameron]] suffers a glitch due to combat damage she took earlier in the series. As a result, she takes on a completely different identity and personality, that of a girl named Allison Young, a future resistance fighter whom her body was modeled after [[spoiler:and who was then subsequently killed.]] By the end of the episode, she recovers, though not without [[NightmareFuel supplying the stuff of many an unpleasant dream]] in the process.
* ''Series/UnitedStatesOfTara'': One character has four alternate personalities: a 15-year-old sex-and-drugs addict called T; a disturbing StepfordSmiler housewife named Alice; and a male, rowdy, alcohol- and brawls-loving motorist called Buck; along with [[spoiler:the mysterious Gimme, who was unknown ''even to Tara'' and serves as a kind of "pure id/protector" alter, who comes out whenever Tara gets too close to discovering something which might traumatise her.]]\\
Seasons Two and Three introduce three more personalities: Shoshana Schoenbaum, an alter based on a therapist Tara creates after reading said therapist's book; Chicken, who is essentially Tara when she was five years old; and [[spoiler:Bryce Crane, an alter based on Tara's half-brother who is believed to have sexually molested Tara when she was a child and is the reason why she has DID in the first place. Bryce then proceeds to apparently kill all of the other alters, although the last episode reveals that Buck, T, and Alice are still 'alive'.]]
* Jacqueline Hyde of ''Series/WhereInTimeIsCarmenSandiego'' has two personalities, TheIngenue and OmnicidalManiac, which she repeatedly switches back and forth between. Her "evil" side speaks in VoiceOfTheLegion.
* This is the premise for the Russian comedy series ''Zaitsev+1''. The protagonist, Sasha Zaitsev (sometimes Latinized as Zaicev) is a typical college nerd who is in love with Nastya, the prettiest girl in his class, although she doesn't know it and stays with her cheating JerkJock boyfriend. Whenever Zaitsev gets hit in the head, is blinded by a bright light, or is deafened by a loud noise, he turns into Fyodor, his wild, rude, and cynical alter ego who likes big women. While Fyodor is actually played by a different actor, only the audience perceives him as a different person. Everyone else just notices that Zaitsev is suddenly acting very differently. Fyodor likes to sleep around, especially with [[NamesTheSame another girl named Nastya]], which becomes a problem for Zaitsev, who can't really explain his problem to others without sounding insane.

* [[http://www.furaffinity.net/gallery/renardv/ Renard]], oh lord, Renard. ''Some'' of his artists pseudonyms, in rough alphabetical order, are: Adraen, Azrael, Bloomin' Nutters, D-Mode-D, Detergent, Emoticon, Furries in a Blender, Hecate, Jackal Queenston, Jaql, Kitcaliber, Kitsune, Klippa, Lollipop, Mayhem, MGD-Crew, MGD Assault Force, Mr. R, Neko, Plusfuchs, Renard, Perdique Darron, Sigma, and Sonitus Vir, ''as well as some others.''
* On Maeror Tri's ''Multiple Personality Disorder'', each track corresponds to the function/role each personality tends to assume, based on now-outdated psychological theories about the condition:
--> 1. The Administrator
--> 2. The Anaesthetizer
--> 3. The Revenger
--> 4. The Protector
* [=SHeDAISY=]'s song "Lucky 4 You" uses multiple personalities in an almost comedic sense.
--> "Number 5 just cries a river a minute,
--> 7 wants to tie you up and drown you in it,
--> 14 just wants to say so long, bygones,
--> 32 wants to do things to you that'll make you blush,
--> 10 would key that El Camino that you love so much,
--> And there ain't nobody wants to mess with 23.
--> Yeah, lucky 4 you, tonight I'm just me."
* Cage9's song "My Doppelganger" (a.k.a. [[TranslatedCoverVersion "Doble Opuesto"]]) is about a guy who hurts his girlfriend (and possibly other people) via his other half, and apparently doesn't seem to understand [[JekyllAndHyde it's himself]] until later in the song.
* Naoki Maeda has so many aliases, he puts Renard to shame. 180, 190, 190', 200, 270, 290, [=RevenG=], Re-Venge, Black Hole, White Wall, [=NW260=], NM, Omega, Z, ZZ, sonic-coll, Neuras, and ''so many others.'' There are at least 50 at last count.
* During the AcidHouse movement, it was trendy for musicians to change their alias for every single song. This was probably started by Music/TheKLF, who used it for [[Literature/{{Illuminatus}} more occultist reasons]].
* In the early years of his career, Music/{{Eminem}} presented himself as having a split personality between Marshall Mathers, the serious, insightful rapper, and Slim Shady, the thuggish rapper with a dark sense of humor. He has occasionally revisited this concept later on, notably in the video for "Monster".
* The Music/{{Vocaloid}} song [[http://youtu.be/X17i0K5gc3g Ten-Faced]] is about a shy girl who develops no less than [[ExactlyWhatItSaysOnTheTin ten different personalities,]] none of whom share memories or realize the others exist. They all end up falling in love with the same guy, who only wants to date one girl. HilarityEnsues. They deal with the problem in the end by performing a SplitPersonalityMerge.
* In Music/TheMegas song "[=GeminEye=]", Gemini Man is shown as having two personalities who initially don't realize their connection to each other: Gemini, a fearful man with a hired killer after him, and [=GeminEye=], a tough PrivateDetective that he hires to protect him.

[[folder:Pro Wrestling]]
* Wrestling/MickFoley had three alters: sadistic Cactus Jack, psychotic Mankind, and ChickMagnet Dude Love.
* Rather than pretend Shannon/The Governor and Wrestling/{{Daffney| Unger}} were different people, Wrestling/{{TNA}} presented them as split personalities. Presumably this means [[Wrestling/RingOfHonor Lucy]], [[Wrestling/{{Wrestlicious}} Draculetta]] and [[Wrestling/{{Shimmer}} Shark Girl]] are also split personalities of Daffney.
* Will White/Bill Black, seen in Fringe Pro Wrestling. Each one is convinced that they are the only one that exists and doesn't know about the other but Will White claims to hear voices and Bill Black talks to himself.
* Wrestling/{{Kane}} seems to have developed a split personality. The helpful and somewhat dorky guy in a suit: Corporate Kane and the vicious fire-wielding Demon Kane. Corporate Kane seems to have no idea about Demon Kane.

[[folder:Tabletop Games]]
* This is actively cultivated by the [[SpaceElves Eldar]] of ''TabletopGame/{{Warhammer 40000}}''. An undisciplined Eldar mind is capable of terrifying extremes -- the species spawned a Chaos God during the depravity of the Eldar golden age -- so they develop different personae for wartime and peacetime to ensure that they don't lose themselves in bloodlust. They don't always succeed, and Eldar who become trapped on the Path of the Warrior will lose their old identities and take up the name and armor of an Exarch who came before them.
* ''TabletopGame/CallOfCthulhu'' supplement ''The Asylum and Other Tales'', adventure "The Madman". An investigator is driven insane by exposure to the Franchise/CthulhuMythos and develops an evil alternate personality.
* In ''TabletopGame/DungeonsAndDragons'', the [[DemonLordsAndArchDevils Demon Lord]] Demogorgon has two heads, but it wasn't until the 3rd Edition that a source mentioned that each had a separate personality. The personality of his left head is named Aameul, the right is named Hethradiah. His two personalities rarely cooperate, and are often fierce rivals. Aameul favors deception, while Hethradiah favors destruction. Strangely, this war within himself often turns out in Demogorgon�s favor. For example, one legend tells how Hethradiah formed an alliance with a powerful lich queen, which left her vulnerable to assassins sent by Aameul. When they killed her, Demogorgon gained her power and lands, so both sides of him benefited.
* In ''TabletopGame/{{Planescape}}'', the elvish spy Farrow has 15 personalities -- each a devout member of a different one of the setting's cutthroat factions.
* In the ''TabletopGame/{{Ravenloft}}'' campaign, there is Malken, the Darklord of Nova Vaasa. His original personality is Sir Tristen Hiregaard, a nobleman who is ''not'' actually evil (listed as Lawful Neutral on his character sheet) and actually perceived as benevolent by some people (it depends on who you ask). However, a dark curse transforms him into a brutal killer called Malken whose victims are often the people Hiregaard himself cares about. No-one in Nova Vaasa save for Hiregaard truly knows Malken's identity; he himself had been unaware for the longest time, believing that he'd managed to keep the curse under control by ordering his servants to lock him in his rooms when he felt its onset, but Malken typically escaped.
* In ''TabletopGame/{{GURPS}}'', a character may be created with multiple personalities. Depending on the "point value" of each personality (they may have different abilities), this can actually count as an advantage! The trigger is a roll against IQ in a "stressful situation"; fail the roll and switch personalities. (If you have more than two, the new one is chosen at random.)
* In ''TabletopGame/{{Orpheus}}'', one of the Flatliners is Jeffrey Rose, a serial killer with no less than seven other personalities, and [[UpToEleven each one of them a serial killer]] in their own right. Making matters more complicated, after Rose's death, his ghostly form develops yet another personality, though at least this one is dedicated to [[EvenEvilHasStandards killing Spectres]].
* The premise of TabletopGame/NewWorldOfDarkness fangame JanusThePersona is this combined with SuperpoweredEvilSide.
* ''TabletopGame/{{Shadowrun}}'' 5th Edition sees the introduction of "Cognitive Fragmentation Disorder," a nanovirus infection which overwrites the mind of the host with that of its own. Over the course of the disease, victims are subject to expressing one, two, or as many as ''twelve'' different personalities as different personality "strains" fight for dominance.
* One of the narrators in the ''TabletopGame/HunterTheReckoning'' Wayward creedbook is Kirsty [=McCallum=], a woman who'd previously had multiple personalities and integrated them; when she was imbued, she split again, her alternate taking the full force of the Wayward imbuing, seeking the elimination of all supernaturals by any means necessary.
* In ''TabletopGame/WraithTheOblivion'' most wraiths and Spectres are split personalities, splitting post-mortem into the Psyche, reflecting their consciousness in life, and the Shadow, reflecting their self-destructive traits. Wraiths have the Psyche as the dominant personality, while Spectres have the Shadow instead.
* ''TabletopGame/EclipsePhase'', unsurprisingly given the ubiquity of BrainUploading, has multiple ways this can happen:
** Split Personality is a mental disorder that can result from events like a botched fork merge or infection with an alien nanovirus.
** Multiple Personalities bioware surgically partitions the brain so it can host an additional Ego, often a fork of the main Ego or a friend of theirs. The Egoes can swap off on control of the body and both have full access to the morph's brain implants so one can fight while the other hacks, for instance.
** A Ghostrider Module is an implant that can run an Infomorph, they can't take control of the body unless it has a Puppet Sock implant but they can remotely control drones.
** The Fenrir is a tank-sized Synthmorph that needs to host six Egoes sharing control to work at full capability.

[[folder:Video Games]]
* This also happened in the ''VideoGame/SpaceAce'' video game (which later became a short-lived cartoon). After being struck by the bad guy's "Infanto-Ray", Ace would sometimes involuntarily transform into Dexter, a skinny, nerdy, teenage alter-ego.
* In ''VideoGame/FinalFantasyVII'', the protagonist Cloud suffers from a case of split personality, where [[spoiler:thanks to Mako/Jenova experiments at the hands of Hojo, the Jenova cells injected inside him take over his brain and create a new persona based on Cloud's desires about being a badass SOLDIER operative like his idol Sephiroth and his friend Zack. The real Cloud is reduced to a mere voice in his head.]]
* One of the villains in ''VideoGame/{{Xenogears}}'' turns out to be [[spoiler:an alternate personality of the main character, created as a coping mechanism against his childhood abuse]]. The villain's name, [[spoiler:"Id"]], offers a vital clue to those with knowledge of psychology. Notably, neither are the original personality, and the situation only gets more complicated once reincarnation's thrown into the mix).
* ''VideoGame/XenoSaga Episode II'' also has a mini-boss who alternates between two personalities, one of which is cold and cruel, the other of which is hot-blooded and nasty. Oddly enough, she doesn't feature in any story sequences and is just a throwaway boss.
* In ''VideoGame/Killer7'', the player-controlled character actually has seven distinct personalities, with their own looks, special abilities, everything. There's even a personality that's albino, one that's paraplegic, and one that's a woman.
** In the first versions of ''[=killer7=]'' the physical body that everybody else sees is Garcian's. There was either a cutscene or just a part of a level that showed this when Dan walked into a bathroom and saw [[strike:himself]] Garcian. This is also alluded to in the released game when confronting Curtis Blackburn when he says "you turned into a badass".
** [[spoiler:In the ending, everything you knew about the split personalities is all torn down. They aren't Harman's split personalities. They're Garcian's, with the weapons of the six recessive personalities in Garcian's suitcase. Also, "Garcian Smith" is a more literal split personality of Emir Parkreiner, the most powerful assassin in the world, so powerful that a god's avatar says that he's not even a mortal being anymore.]]
* ''VideoGame/{{Psychonauts}}'':
** [[spoiler:Ford Cruller]] suffers from this due to a battle that shattered his psyche in the past and is only able to remain stable within his underground sanctuary, which houses one of the largest [[AppliedPhlebotinum psitanium]] deposits. His personalities are [[spoiler:all named Cruller and serve as several different roles in the camp, ranging from Ranger Cruller, Admiral Cruller, Chef Cruller, and so on.]]
** Fred Bonaparte and his split personality Napoleon Bonaparte -- Fred knows he's crazy, he just can't seem to get rid of Napoleon until Raz helps him out. (Crosses over with GeneticMemory).
* Manah, the CreepyChild BigBad of ''VideoGame/{{Drakengard}}'', seems at first to be suffering from this. It later turns out to be part-SplitPersonality, part-DemonicPossession.
* ''VideoGame/SuperRobotWars Original Generations'': In ''Mugen no Frontier: SRW OG Saga'', Lamia {{Expy}} Aschen Brodel has personality split disorder. Just wait until she reveals some skin, and all the stoic android facade gets replaced with a GenkiGirl personality.
* ''VideoGame/SuperRobotWars'', SplitPersonality is the gimmick of the heroine of SRW Destiny, Cliana Rimskaya. One is a rougher, [[TheStoic stoic]] girl that is capable of piloting and kicking ass, one is a NiceGirl.
* ''Franchise/TheElderScrolls'':
** The series' [[OurGodsAreDifferent Aedra]] have oddly conflicting personality traits or govern over unusual combinations of spheres. Much of this can be traced back to [[FounderOfTheKingdom St. Alessia]]'s founding of the [[SaintlyChurch religion of the Eight Divines]], which stitched together the classic [[OurElvesAreBetter Aldmeri]] pantheon her Nedic people were used to with the old Nordic pantheon of her [[HornyVikings Nord]] allies. Examples include Kynareth being the Goddess of the Air with a FriendToAllLivingThings slant while also being a [[{{Valkyries}} Valkyrie]] and {{Psychopomp}}, and Stendarr being the God of Justice and... [[OddJobGods taking prisoners alive for ransom]].
** Akatosh, the [[DragonsAreDivine draconic]] God of Time and [[TopGod chief deity]] of the Aedra gets hit with it especially bad. To note:
*** As mentioned above, this applies to most of the Aedra. However, Akatosh gets it the most. This is taken to the point where Cyrodiilic stained glass and statuary depictions of him show that he [[MultipleHeadCase has two heads]], a dragon head and a human head.
*** Crossing over with LiteralSplitPersonality and PiecesOfGod, In-universe speculation is that [[BeastOfTheApocalypse Alduin]] (and perhaps all [[OurDragonsAreDifferent dragons]] and Dragonborn) is more akin to a fragment of Akatosh's being rather than his son. (For what it's worth, Alduin disputes this claim.)
*** The Maruhkati Selective, an extremist sect of the [[FantasticRacism already-extremist]] Alessian Order, tried to force this onto Akatosh by using powerful magics and the Staff of Towers to split the Aldmeri aspect of Auri-El from Akatosh. It's not clear if they actually succeeded, but their efforts ended up causing [[RealityIsOutToLunch The Middle Dawn]], the most extreme [[TimeCrash Dragon Break]] in history.
** Sheogorath, the [[OurGodsAreDifferent Daedric Prince]] of [[MadGod Madness]], is [[spoiler:a split personality of Jyggalag, the Daedric Prince of Order]]. When the other Daedric Princes grew afraid of how powerful [[spoiler:Jyggalag]] was becoming, they used their powers to [[HijackingCthulhu curse him into becoming the very thing he hated the most]]. ''[[VideoGame/TheElderScrollsIVOblivion Oblivion]]'''s ''Shivering Isles'' expansion ends with you [[spoiler:[[LiteralSplitPersonalities splitting them into two separate and distinct beings]] by taking on the mantle of Sheogorath ''[[DeityOfHumanOrigin yourself]]'']].
** ''Shivering Isles'' is also contains a village called 'split' where each citizen has been turned into two people based on their Manic and Demented sides.
* In ''[[VideoGame/ParappaTheRapper Um Jammer Lammy]]'', Captain Fussenpepper has a SplitPersonality, making him either TheDitz who can't tell right from left or a DrillSergeantNasty and War Hero.
** ''VideoGame/ParappaTheRapper 2'': Hairdresser Octopus's crazy red side is revealed to be this ''[[AllThereInTheManual in the manual]]''.
* ''Metal Gear Solid'' games:
** In ''VideoGame/MetalGearSolid2SonsOfLiberty'', the protagonist Raiden was [[spoiler:a deadly child soldier known as "Jack the Ripper", but after coming to America, blocked out this persona from his memories.]] This is explored further in ''VideoGame/MetalGearRisingRevengeance'', where [[spoiler:the Ripper persona resurfaces, to bloody and devastating effect for Raiden's enemies]].
** In ''[[VideoGame/MetalGearSolidPortableOps Portable Ops]]'': [[spoiler:Twins Elisa and Ursula are in fact one and the same.]]
*** Crying Wolf of ''VideoGame/{{Metal Gear Solid 4|GunsOfThePatriots}}'' suffers from a split personality. The "wolf" personality [[spoiler:has a compulsion to murder children]] and the "crying" personality [[spoiler:mourns those killed by the "wolf", but seems unaware that she is the "wolf".]]
*** The Beauty and the Beast Unit in general, really. In all of their back stories, they end up [[spoiler:doing something morally atrocious in response to extreme hardship and trauma during a war,]] and are found consumed by some manner of emotion in disbelief that it happened, [[spoiler:blaming a wild animal for their actions.]] All four stories end with Drebin saying, [[spoiler:"of course, there was no (animal)."]] They're all so similar, someone coded a Beauty and the Beast Unit back story generator.
* Socks, the lunatic boxer from ''Facebreaker'', has two personalities (a nice, English-accented intellectual and an angry psychopath), which manifests in the [[ExactlyWhatItSaysOnTheTin sock puppets]] that he uses for boxing gloves.
* A pirate appears in ''VideoGame/EscapeFromMonkeyIsland'' who has developed two additional personalities in order to cope with having his ego shattered by the Ultimate Insult. They are manifested through the puppets he wears in a Punch and Judy type of show, which themselves take on the forms of the series' hero and villain in appearance, though not so much in personality.
* ''VideoGame/SoulSeries'':
** Tira, who has had her brain broken by prolonged exposure to [[ArtifactOfDoom Soul Edge]], and she flips back and forth between her original "joyous" personality (where she'll kill you with a [[PsychoticSmirk smile on her face]]) and her "malicious" one (where she'll just kill you).
** Siegfried: before Nightmare could fully take over (and before Nightmare became a completely separate entity), Siegfried and Nightmare were sharing one body, and Siegfried would usually wake up covered in blood.
* [[spoiler:Therese and Jeanette Voerman]] from ''VideoGame/VampireTheMasqueradeBloodlines''. You never get the whole story, but the conversation you have with them after the fight in the diner suggested the split either happened when [[spoiler:Therese was sexually abused by her father, when their father shot himself/was shot by Therese, or after they were Embraced by a Malkavian.]] WordOfGod is that the writers carefully researched DID in order to maintain the arc's plausibility. And considering that the Malkavian Madness Network works like a very unusual kind of HiveMind, it can't be entirely ruled out that they actually ''did'' start out as twin sisters, one of whom didn't physically survive Embracing.
* In ''VideoGame/ClockTower II: The Struggle Within'', the entire storyline is based around a girl who has a malevolent split personality.
* ''VideoGame/TalesSeries'':
** Emil Castagnier from ''VideoGame/TalesOfSymphoniaDawnOfTheNewWorld''. Normally, he's very timid, sweet, and cowardly. But when he goes into his humorously named, "Ratatosk Mode", he turns much more vicious and merciless. Though, [[spoiler:he is actually Ratatosk, and "Emil" is actually a fabricated personality]], but still...
** In ''VideoGame/TalesOfVesperia'', [[spoiler:Raven and Schwann]] sure don't act like the same person. [[spoiler:Raven]] is his ObfuscatingStupidity disguise, with hints of BecomingTheMask.
* Brad Kilstein from ''VideoGame/PsychicForce''. For someone who is voiced by Creator/RyuseiNakao, he is surprisingly soft-hearted and abhors fighting and violence. However, at one point, his personality may revert into the typical Ryŭsei Nakao character: a brutal, sadistic AxCrazy PsychoForHire.
* ''VideoGame/EternalDarkness''' Xel'lotath speaks in two voices - one is well-spoken, rational, and almost as [[MagnificentBastard imperious]] as [[ElementalRockPaperScissors the paper to her scissors]] Ulyaoth, while the other sounds extremely paranoid and somewhat delusional, always using a quiet but harsh whisper. In cutscenes where she chats with [[TheDragon Pious]], it sounds like a conversation with three people. Fittingly, she is the Ancient of insanity.
** Not only does she have two voice actresses who each take a personality, ''[[UpToEleven they also swap the rational/irrational role depending on the scene]]!''
* Sakubo, a character of ''VideoGame/DotHackGU'', has a serious case of this. Originally stating he and his sister shared a character, we later find out they share the character. Saku, the girl side, is the more violent side and Bo, the actual person, is a shy boy who developed Saku to help him stand up for himself. It's essentially like sticking Blackrose and Elk into one body. Add in the fact that Saku is obsessed with 'White Haired Pretty Boy' Endrance and things get a little weird if you think on it too long...
* Dinah, one of the spirits from ''VideoGame/SummonNight: Swordcraft Story 2'' has a GoodAngelBadAngel split personality. The "bad angel" personality is the default one, though sometimes her "good angel" side will shine through every now and then to apologize profusely for Bad!Dinah's rudeness.
* Tink from ''VideoGame/Disgaea2CursedMemories'' has two sides -- the "blue" personality, which is calm, polite, and timid, and the "red" personality, which is lecherous, short-tempered, rude, and selfish. It takes a magic spell to suppress his "red" side in the cutscenes, though he can switch between them freely in actual gameplay. When in the "red" side, he gets a boost to his stats by being near female characters.
* Agent Francis York Morgan of ''VideoGame/DeadlyPremonition'' often has conversations with "Zach", to the confusion of others. [[spoiler:Near the end, it's revealed that Zach is the original personality and York was developed as a child in order to protect Zach's psyche. Eventually, Francis York Morgan goes back to being Francis Zach Morgan in order to confront Forrest Kaysen for the finale.]]
* Ethan from ''VideoGame/HeavyRain'' experiences occasional blackouts, and he believes that these blackouts occur when his alternate personality (who he believes is the Origami Killer, who is responsible for kidnapping his son) takes over. [[spoiler:The actual Origami Killer is a completely separate character, and there's no real explanation given for Ethan's blackouts.]]
** [[spoiler:The reason behind Ethan's blackouts could be both the trauma he suffered from the accident he had trying to save Jason, or the stress caused from it. That and since the Origami Killer has been over the news recently, he could have (unconsciously) attempted to find a way to blame himself for something.]]
* Played realistically (for once) in ''VideoGame/MassEffect1'' with the character of Talitha, who only shows up in certain branches of the PlayerCharacter's MultipleChoicePast. She was kidnapped by batarian slavers as a child; after her release, she is a ThirdPersonPerson who perceives her abusive experiences as having happened to someone else.
* ''VideoGame/InazumaEleven'' 2[='s=] Fubuki Shirou has a special mention of a SplitPersonality aside from other characters with dual modes. His regular persona, a soft-spoken and timid defender, and his alter persona, [[spoiler:created from a memory of his dead brother,]] a HotBlooded and reckless forward. The issue is developed further in the story.
* Gemini from ''VideoGame/SakuraWars: [[VideoGame/SakuraWarsSoLongMyLove So Long, My Love]]'' seems to be pulling a not-very-convincing masked vigilante act, until it's eventually revealed that she has a sister Geminine... living inside her.
* The ren'ai game ''Ori, Ochi, Onoe'' is a rare instance of two people having a love triangle or in this case, rectangle.
* The ''VideoGame/FalloutNewVegas'' DLC, ''Dead Money'', introduces Dog/God, a Nightkin with split personality. Dog is the dumb, violent, ExtremeOmnivore who obeys Elijah's every whim and brings victims to the Sierra Madre to help him break in. God is exceptionally intelligent and well-spoken, but very cold and calculating and regularly threatens the people he's with. Dog comes out when a recording of Elijah's voice is played, and God comes out after Dog hears a recording of God's voice. In the end, [[spoiler: Dog attempts to commit suicide and the player can kill him or talk him out of it, which allows for him to encourage one of the personalities to take over or merge both of them into a single balanced being.]]
** All of the Nightkin have some form of this due to their overuse of Stealth Boys, Their illness has more in common with real-world dissociative identity disorder, but is referred to as schizophrenia in accordance with 1950's science.
* ''Mystery Trackers: The Void'' involves the sinister events following the disappearance of Marius Void and his criminally-inclined "brother" Sirius.
* [[LoveInterest Goal]] gets a variation on this in ''Chaos on VideoGame/{{Deponia}}'' -- Her mind was stored on a hard-disk-like brain implant, but after some [[IdiotHero Rufus]]-related shenanigans, the data on it is split into three disks, each of which contains a third of Goal's personality. Rufus can use a remote control to [[FlipPersonality flip]] Goal between her selves. Tuning in the right Goal for the right situation is a core mechanic of the game.
* In ''Videogame/{{Borderlands 2}}'', Krieg suffers from this as a result of the experiments Hyperion put him through to make him such a deadly killing machine. His dominant, active personality is a lunatic, buzz-ax-swinging berserker who spends most of his time spewing jumbled nonsense (i.e. trying to talk to Maya resulted in him screaming "I'M THE CONDUCTOR OF '''THE POOP TRAIN!'''" at the top of his lungs). His original personality has been downgraded to a voice in his head that tries to steer the Psycho's murderous impulses towards [[PayEvilUntoEvil more deserving targets]], but can't do very much beyond that. About the only thing the two consistently share is that both are in love with Maya and believe that she is the one capable of curing them. Or at least the sane personality does. The Psycho personality [[ForTheEvulz doesn't particularly]] ''[[ForTheEvulz want]]'' [[ForTheEvulz to be cured]].
* In ''VideoGame/SpecOpsTheLine'', [[spoiler:The John Conrad that Walker spends most of the game interacting with appears to be a hallucinatory second personality created by Walker's stress and latent PTSD. Walker spends half the game pushing the blame for all his mistakes onto Conrad, whose incarnation Walker interacts with tries to bring to light all the self-justifications, repressions, and outright lies Walker forces himself through in order to avoid coming to terms with how messed up his situation has become. Just how Walker decides to come to terms of it when he meets the real Conrad in the end segment and finally can't deny his situation any more makes up much of your choices in the ending.]]
* In ''VideoGame/FireEmblemAwakening'', Noire has two personalities: a meek, timid one; and a bloodthirsty LargeHam that provides one of the more memorable catchphrases in the game.
** This second personality arose from a talisman that her mother made for her, and with it she was able to survive the [[spoiler:[[AfterTheEnd destroyed world]] [[BadFuture of the future]]]].
* The main heroine of ''VideoGame/TimeAndEternity'' has one in the form of the soul of a completely different person, Towa, inhabiting her body. Switching out between the two of them, with their different personalities and fighting styles, is a game mechanic.
* In the "bad" ending of ''{{VideoGame/Strife}}'', it is revealed that [[spoiler:[[VoiceWithAnInternetConnection Blackbird]] and [[BigBad The Entity]] are the same person. Whether Blackbird was a real woman on this plot path, and what became of her if she was, is not revealed]].
* [[MonsterClown Perpentach]], the mad king of the Belseraphs in ''VideoGame/{{Civilization}}: VideoGame/FallFromHeaven'', is this trope to a ridiculous degree. Due to his lineage, he has an incredible affinity for Mind Magic -- so much so that he [[PowerIncontinence can't even control it properly.]] Any ordinary person who got close to him had their minds stolen from them, turning them into his slaves and adding their personality to his own. Hundreds of minds all locked within his own quite understandably made him snap, ''hard.'' The calamity ended only when his master Kylorin solved the problem by locking Perpentach's mind away and imprisoning Perpentach within a derelict building in a remote swamp... Which did the trick, until a wandering circus troupe got too close, hence [[CircusOfFear explaining the theme of Perpentach's current form as well as his nation as a whole.]]
* Royal Sorcerer Navlaan from ''VideoGame/DarkSoulsII'' appears timid and gentle if you approach him in human form, but should you speak to him in hollow form, you'll meet his other personality -- a malicious and evil being who will send the player on assassination missions. The good side of Navlaan sealed himself behind a magical barrier after the evil side went on a murder spree, and begs the player not to let him out. If you do let Navlaan out, you'll be attacked by dark phantoms of his evil side all around Drangleic.
* Sho Minazuki from ''VideoGame/Persona4ArenaUltimax'' is [[BloodKnight violent]], childish and [[PungeonMaster loves bad puns]]. He has another personality (born from the Plume of Dusk implanted into his body) that is [[TheStoic calm]], calculating and ruthless. In the English localization, the wilder personality is referred to as 'Sho', while the other is referred to as 'Minazuki'.
* In ''VideoGame/TheUltimateHauntedHouse'', the house's owner Gahan Wilson suffers from this, due to a formula he drank. [[JekyllAndHyde One personality is good, the other is evil]], and it is difficult to tell which one is in control at first glance. Part of the difficulty of dealing with Gahan is that [[HydePlaysJekyll Evil Gahan will often pretend to be Good Gahan]] so that he can mock you and curse you after you give him an item.
* In ''VideoGame/MugenSouls'', the main plot revolves around Chou Chou recruiting new peons, continents, and even planets as her allies with her different split personalities.
* ''VideoGame/RandalsMonday'': One of the patients at the therapist office. Robert is the normal personality, an Alan is the crazy one.

[[folder:Visual Novels]]
* [[spoiler:Miku]] in ''VisualNovel/AProfile'' claims this, but Kaine claims it's incredibly unlikely because not only is DID extremely rare, but her behavior simply doesn't match up to what it should be because the claimed personalities are aware of each other, which defeats the whole point. [[spoiler:He's mostly right, but not entirely.]]
* In ''VisualNovel/UminekoWhenTheyCry'', Rosa is seen by her daughter Maria as having one in order to justify [[AbusiveParents her abusive behaviour]], interpreting her mother's violent mood swings as being possessed by a "Black Witch".
* In ''VisualNovel/{{Remember11}}: The Age of Infinity'', Keiko Inubushi suffers from Dissociative Identity Disorder (or so we're told), resulting in her being sent to the SPHIA psychiatric hospital when one of her personalities commits several murders. Later, protagonists Kokoro and Satoru allow their companions to believe this about them (They are actually undergoing a series of {{Freaky Friday Flip}}s, but find that its easier to convince their companions "I have two personalities", rather than "My mind randomly switches with somebody else's"). The novel even touches upon the legal implications for DID which allowed Keiko to be considered criminally insane much to the anger of family members of her victims.
* In ''VisualNovel/DanganRonpa'', [[spoiler:Genocider Syo, an infamous serial killer]], is the split personality of [[spoiler:Touko Fukawa]]. Despite this, [[spoiler:Genocider Syo doesn't actually kill anybody during the course of the game, despite being suspected twice as a murderer]]. The personalities switch when one of them sneezes, and they don't share the same memories. As you can imagine, they're both very different people: [[spoiler:Touko is gloomy and pessimistic, while Genocider Syo is a gleefully sadistic LargeHam]]. About the only thing they have in common is [[spoiler:their infatuation with Byakuya Togami]].
* Lisianthus of ''VisualNovel/{{Shuffle}}'' absorbed the soul of her unborn sister while still in the womb. The two take turns being the dominant personality. In the original visual novel she has no name but is known as Reverse Sia. Giving her the name Kikyo becomes a plot point.
* ''Franchise/AceAttorney'':
** Ben and Trilo seem to have something similar to Batman's Ventriloquist, in that Ben's doll Trilo acts as if it has a mind of its own and routinely beats up its owner. Trilo also seems to forget he's a doll at times - at one point, he tries to get Ben to sing with him in a round.
** A serious example is [[spoiler: Matt Engarde]], who refers to his evil side as his real self (and thus a separate identity) and does so in the third person, implying that he might have a split personality.
** In ''[[VisualNovel/PhoenixWrightAceAttorneySpiritOfJustice Spirit of Justice]]'', [[spoiler: Uendo Toneido has four of them. The "main three" include Uendo the fairly average rakugo performer, Patches the happy-go-lucky jester, and Kisegawa the stern female courtesan. These three personalities are all conscious at the same time, and decide which one will take over based on which is most appropriate for the situation. The existence of a fourth personality named Owen which takes over when the other three are unconscious is eventually revealed, and briefly suspected of being the case's killer. This is very quickly disproven, however, upon the reveal that Owen is a timid 5-year old boy.]]
* Tohno[[spoiler:/Nanaya]] Shiki from ''VisualNovel/{{Tsukihime}}'', with a twist: [[spoiler: ''neither'' of them is the original. His main Tohno identity was added after "the incident" via brainwashing, which also '[[DeathOfPersonality killed]]' the original, but it remains as his main identity even after he finds out the truth. The alternate Nanaya identity is a mechanism for dealing with his murderous instincts, identity issues, and sundry other mental problems who was patterned after the psychotic killer Tohno erroneously believes the original Nanaya would have been like if he were still alive (in fact, the original Nanaya was a perfectly pleasant child who valued the lives of others, albeit a bit aloof, something of a shut-in, and thoroughly traumatized).]]
** And then from the spin-off ''Manga/HanaNoMiyako'', there's also [[spoiler: Shiki/SHIKI Nanaya, which is further complicated by the fact that SHIKI may or may not be the selfsame Shiki Nanaya from Tsukihime.]]
* From ''VisualNovel/GrisaiaNoKajitsu'' we have [[spoiler: Michiru, who shares her body with the consciousness of the girl whose heart donation she received. At the start of the story, Other!Michiru only comes out when Michiru needs help while Michiru is left with no memory of it happening, but by the end they've learned to cohabitate.]]
* In ''VisualNovel/{{Sunrider}} Liberation Day'', Asaga develops one as a by-product of [[HeroicRROD overusing]] her SuperMode. While Asaga herself is a cheerful GenkiGirl and self-styled Hero of Justice, the new personality is a merciless KnightTemplar fixated on meting out “justice” to the entire galaxy and will push Asaga to kill anyone it considers to be evil. The new personality only has control when Asaga uses her powers, but both personalities are aware of each other and actually [[TalkingToThemself hold a conversation at one point]].
* ''VisualNovel/ShallWeDateNinjaShadow'' has [[spoiler: Kagura and his "other self", Homura, who was "born" from Kagura being the SoleSurvivor of a ninja squad that failed a mission [[FromBadToWorse in the worst way possible]]. They're a SensitiveGuyAndManlyMan duo in one body: Kagura is quiet and gentle plus very sweet to everyone and one Hell of a SuperStoicShopKeeper, while Homura is a brutal BloodKnight who considers Kagura as his OnlyFriend and [[DevotedtoYou is completely devoted to him]].]]
* In ''VisualNovel/MysticMessenger'''s Another Story, [[spoiler:Unknown/Saeran is depicted as having a split personality. The implication is that unlike in the normal story where he doesn't have a split personality and is just BrainwashedAndCrazy, Another Story takes place a couple of years earlier when the brainwashing hadn't completely wiped out his original kinder self (Ray) yet who can still keep his more psychotic personality somewhat in check]].
[[spoiler: Mitsuki/Shiho]] in VisualNovel/DoubleCast, with [[spoiler: Shiho being her regular personality and Mitsuki being her yandere personality. The latter personality was created due to the trauma of Shiho seeing her sister(who was also named Mitsuki)'s body and her love/hate relationship with her.]]

[[folder:Web Animation]]
* In ''WebAnimation/FiftyPercentOff'', there are multiple personas holed up inside Haru's brain that have conflicting interests and personalities, most notably the "Impulsive Haru"
* ''Machinima/RedVsBlue'':
** The Director of Project Freelancer needed multiple {{AI}} for his program but only had enough resources to create one, [[spoiler: made from his own brain patterns,]] the Alpha. To get around this, he subjected Alpha to enough MindRape to cause its psyche to fragment. The fragments were then harvested and [[LiteralSplitPersonality retooled into independent AI]], and as you can imagine more than a few ended up unstable. Worse, the main antagonist of the ''Reconstruction'' series has about eight of those fragments inside his head at the same time, and his/their goal is to collect the rest and [[SplitPersonalityMerge reunite with the Alpha]].
** In season 13, Doc, after spending several months trapped in another dimension and then lost in the caves of Chorus, eventually developed a split personality of his own- and it's exactly identical to Omega/O'Malley, the AI that once controlled him during the Blood Gulch Chronicles.
* In ''WebAnimation/AlfredsPlayhouse'', there is the superficially happy but very needy Alfred Alfer, who is secretly traumatised by his abusive childhood and uses a fantasy world to avoid thinking about his abuse, and there is vengeful, megalomaniacal Dictator Alfred, who wants to [[TakeOverTheWorld rule the world]] and is cruel to Alfred.

[[folder:Web Comics]]
* In ''Webcomic/{{Jix}}'', the titular character is the second personality of an invader, Remula, from an alien race who was surveying Earth. She stayed on Earth until she was sane again. She's manifested two more personalities since then, Lamerix the MadScientist and (male) superhero The Ambis.
* Kano, the protagonist of ''Webcomic/{{Kagerou}}'', has several personalities. The personality that answers to "Kano" is initially not aware of the others.
* ''Webcomic/MountainTime'' has [[http://mountaincomics.com/2009/08/27/mountain-time-89/ Donna the Bears]], who has multiple personalities that are all bears.
* ''Webcomic/TheWotch'':
** Repeated transformations into a mind-altering form seem to cause this. For example, the 'Lilly amulet' causes the wearer to turn into a slightly hyperactive [[GenderBender gender-bent]] child. At the beginning of the comic, the minds of Evan and Lilly are separate (Evan is gone while turned into Lilly, and vice versa) except for one incident where their minds were switched. Lately, however, Lilly seems to be present even while Evan is himself. Similarly, while the Jason-Sonja transformation was a simple GenderBender, they seem to be diverging slightly as Sonja gains time existing.
** [[OurWeresAreDifferent Weres]] seem to be similar, with the normal form and were form having separate minds (e.g. Yukio/Yukiko). Samantha and Katie are exempt because of the amulets that specifically suppress the were-mind and leave the normal mind in control, to the extent that they never developed separate minds in the first place (though Katie transformed once or twice without the amulet, all examples of multiple-personalities were developed over multiple and/or long-lasting transformations).
** Myrh (formed when magical slime ate Lord Sykos' maid) goes through a short time with this when a mind-meld with Ming and some jellybeans cause her human and slime portions to rebel against each other, as the slime [[BattleInTheCenterOfTheMind attempts to become Ming.]]
* Somewhat minor character Clive/Ernest in ''Webcomic/{{Concession}}'': Clive is passive and straight, while Ernest is gay and [[http://concessioncomic.com/index.php?pid=20100226 rather assertive]].
* ''Webcomic/BobAndGeorge'': [[http://www.bobandgeorge.com/archives/031026c George has an attack before the personality realizes it has the wrong character]] -- and [[TheLordOfTheRings work]].
* ''Webcomic/{{Homestuck}}'': [[spoiler:Calliope and Caliborn]]. She is probably the sweetest, kindest, most innocent character in the entire comic, and she uses the most passive class possible in the game. He, on the other hand, is evil, has the most active class possible in the game, loves to pretend he's [[Franchise/{{Saw}} Jigsaw]], is the original incarnation of the BiggerBad, [[ArsonMurderAndJaywalking and is turned on by his disgust for tender, non-sexual displays of affection.]]
** This is ''normal'' for juveniles of their species. At what amounts to puberty, one of the personalities "kills" the other one and takes over the body permanently. At least in this specific case, the two personalities have been aware of each other since early childhood and communicate through notes. They're ... not fond of each other. What's not normal, even by their species's standards, [[spoiler:is using SBURB's DreamLand mechanics to kill the other personality way ahead of schedule.]]
** There's also [[spoiler:Gamzee]], though in his case there seems to be ''three'' personalities: a 'good' host personality, which is kept dominant to begin with by [[spoiler:Sopor slime]] and two 'evil' (or rather, sociopathic) alters.
* ''[[http://healthymultiplicity.com/Zyfron/Gemini/ Gemini]]'' is a slice-of-life about Bernie and Z, and their life as multiple (and Z being a trans woman.)
* Chelsea Grinn of ''Webcomic/{{Chimneyspeak}}'' has four, progressively less sane, personalities.
* In ''Webcomic/MoonCrest24'', Derek and Dwayne both have the spirits of Drake and Daniel inside them respectively. And while Dwayne and Daniel are aware of each other, Derek and Drake are not.
* [[JekyllAndHyde Anna/Susan]] Enfield from ''Webcomic/{{Sire}}'', due to being a [[InTheBlood descendant]] of [[Literature/TheStrangeCaseOfDrJekyllAndMrHyde Edward Hyde]].
* The Webcomic/{{Drowtales}} character known as Sharess takes the Split Personality Trope and dials it UpToEleven. In the Daydream Archive Story dealing with her life after becoming a disembodied entity of Pure Aura (Aura is the Drow equivalent to a soul) [[spoiler:she battles a couple of Nether Gods, consumes their essence, rewrites the existence of the entirety of the Nether Plane that had currently been attacking the Drowtales Main Archive's world while simultaneously sealing all portals into that plane with herself lost on the other side of the portal. Once that is done, she promptly shatters into thousands of tiny individual consciousnesses, each with the individual ability to rewrite the physical reality of the Nether World she found herself inside of within a few hundred meters of herself. They can consume other copies of herself to access the ability to manipulate reality on a wider scale. Their children also have this ability. So yeah, that's thousands of Mini-Gods running around upon this poor unsuspecting Nether World...]]
* In ''Webcomic/GeneralProtectionFault'', the MirrorUniverse Nega-Trish ''claims'' to be "schizophrenic" to explain her occasionally slipping mask, and the regulars' brief encounter with Posi-Trish. Both Nick and Patty realise that a geek with a psychological disorder would use the correct term for it, [[ConvictionByContradiction therefore she's lying]].
* In ''Webcomic/BusterWildeWeerwolf'', Bernard the straight human and Buster the gay werewolf share the same body.
* You know how Yumie and Yumiko from ''Manga/{{Hellsing}}'' are mentioned above? [[spoiler:The webcomic ''Webcomic/AndShineHeavenNow'' takes it one step further, where it's revealed that aside from Yumie, Yumiko has ''nine more personalities'' that were being suppressed by Iscariot. She suffered a temporary HeroicBSOD when Heinkel released them as the personalities sorted themselves out. In a big ShockingSwerve though, Yumiko was never the original personality. She was just led to believe she was such because she's the easiest to control.]]
* ''Webcomic/DumbingOfAge'': Amber copes with her trauma and stress by creating Amazi-Girl, a vigilante modeled after Batman. The twist is that ''Amber'' [[http://www.dumbingofage.com/2017/comic/book-7/03-the-thing-i-was-before/unfinished/ is the dangerous one,]] because it's Amazi-Girl who shares Batman's stoicism, strict moral code, and self-control. [[spoiler:After ''Amber'' nearly guts Joyce's would-be rapist Ryan, Amazi-Girl embodies this trope even more, as she's been going out fighting crime...and Amber has no memory of it.]]

[[folder:Web Original]]
* ''Roleplay/DestroyTheGodmodder'' has lots of these. It's become a {{running gag}}.
** Then the GM came down with a bad case of this.
** Some of the players mess with this by having other characters try to take over their posts.
* [[WebVideo/TheSpoonyExperiment Spoony]] has a split personality named 'Dr. Insano' -- for ''WebVideo/{{Kickassia}}'', [[MultipleChoicePast at least.]]
* Pretty Pink Ponytails from ''Literature/AngelOfDeath'' has an alter named Anita who sometimes takes over.
* Merry, in the ''Literature/WhateleyUniverse'', has four personalities: Chaddy, her more innocent child self; Chad, her cynical, distrustful, early adolescent self; Merry, the most normal one and the dominant personality; and Mai, an evil AI she defeated that took up residence in and merged partially with her mind. Eventually these four were separated into pairs when Merry got accidentally cloned; Chad and Chaddy now live in Petra's head, while Merry and Mai now live in Paige's. And to those of you wondering why two of those personalities have male names... it's the Whateley Universe. [[GenderBender Figure it out.]] Fey, meanwhile, doesn't so much have a SplitPersonality as she ''actually has'' another person in her head, specifically Aunghadhail, an ancient Sidhe queen who died millennia ago but is now BackFromTheDead, sort of.
* In the ''Roleplay/GlobalGuardiansPBEMUniverse'', heroic crimefighter Arsenal has no idea that she is also the psychotic assassin Demise.
* ''WebVideo/EverymanHYBRID'' heavily implies this:
-->'''Evan:''' You may scare Evan, but he's just a bitch.
* Kaleigh Jones from v1 of ''Roleplay/SurvivalOfTheFittest'' had two, in the form of child-like "Carly" and nymphomaniac "Freya". Bizarrely, Kaleigh seemed capable of deciding which of her personalities was in control and when.
* In ''WebVideo/TenLittleRoosters'', Ryan Haywood's "Mad King" persona from ''[[LetsPlay/AchievementHunterMinecraftSeries Let's Play Minecraft]]'' is treated as this, to the point where [[spoiler:he's afraid he actually killed Creator/GavinFree and Creator/MichaelJones in the first two episodes]]. In actuality, this was part of [[spoiler:Barbara Dunkelman's]] EvilPlan to frame Ryan as the murderer.
** In ''WebVideo/ElevenLittleRoosters'', it turns out that [[TheMole the Saboteur]] went insane at some point before the start of the series and developed an alternate persona encouraging them to betray the rest of the Rooster Corps. [[spoiler:It's Gavin the 3rd, and his evil (well, [[TheSociopath evil]]''[[TheSociopath er]]'') persona is his supposed [[VoiceWithAnInternetConnection support coordinator]], Operator Mikey.]]
* From LetsPlay/VenturianTale's videos, we get Johnny Ghost and Jimmy Casket. Johnny is a (mostly) sane paranormal investigator, and Jimmy is an insane mass murderer, whose weapon of choice is a [[KnifeNut knife]].

[[folder:Western Animation]]
* ''Series/AceLightning'' has [[MeaningfulName Random Virus]], a [[CyberneticsEatYourSoul cyborg]] with one good and one evil personality. He's constantly fighting between them though how much these two sides of him are indivdiuals is unclear.
* PlayedForLaughs as a twist in ''WesternAnimation/AmericanDad'' when Roger, the alien with the PaperThinDisguise, hunts down someone who used his credit card only to discover it's himself, as a persona of his that gained a will of its own.
** Stan ends up going through something similar in another episode: the other personality takes over when Stan is asleep, and is Stan's long-ignored conscience.
* ''WesternAnimation/BatmanTheAnimatedSeries'':
** Played seriously with the "evil" personality of Two-Face almost completely consuming the mind of Harvey Dent to the point where the "good" personality rarely surfaced again, much to Batman's dismay. This got taken to a weird extreme when the [[KnightTemplar killer vigilante]] "The Judge" appeared and started trying to kill Batman's rogue's gallery, including Two-Face, with death traps. [[spoiler:The Judge turned out to be an alternate personality of Two-Face himself, who had no idea that he was the same person.]]
** Baby Doll alternated between being Baby, the CheerfulChild she once played and whom she had slipped into in obsession, and Mary Dahl, the sane adult woman. Her account of how it split was a TearJerker. [[http://www.youtube.com/watch?v=gj45viQGBqM&feature=related Watch from 8:30 for it]].
--->'''"Father":''' We're ''actors'', remember? You cancelled our show because you whined you weren't getting enough attention!\\
'''Baby Doll:''' But I knows now I made a boo-boo! ''[as Dahl]'' It was hard for me out there. I studied and trained and auditioned, but no-one wanted me. Over the years I remembered how happy I was with all you around me, and the folks at home watching me each week... Me. ''[as Baby]'' Baby Doll. Hee hee! Now I'm Baby for good, and everyone will love me again!
** And then there was the Ventriloquist and Scarface, the latter of which is a separate personality of the former, embodied in a ventriloquist dummy with a machine gun. Both personalities are present at the same time, it's just that the Ventriloquist can't acknowledge that he's the one working Mr. Scarface and giving him voice rather than the puppet being his own person. This is clearly seen where Scarface sleeps in a lavish bedroom, and the Ventriloquist sleeps in a closet. [[DemonicDummy It's occasionally hinted that Scarface has a will of his own]], but that's just silly.
*** ''WesternAnimation/TheBatman'' takes this even further: Scarface's ventriloquist is "Reformed" by being given a new puppet meant to be a "Good" alternate personality. [[spoiler:And it works, too: the new puppet even gives Batman the hint that Scarface is on the loose again.]]
*** The ''WesternAnimation/BatmanTheAnimatedSeries'' version of Scarface episode went so far as to describe the Ventriloquist and his dummy as two separate people who were born trapped in the same body, with Batman making an analogy to Siamese twins. ''Split Personalities Do Not Work That Way'', to put it mildly, but the series did go on to provide a more realistic portrayal of Dissociative Identity Disorder with Two-Face, whose personalities are different facets of Harvey's mind.
* Done as a visual pun in the ''WesternAnimation/BeanyAndCecil'' episode "The Seventh Voyage of [[PunnyName Singood]]." Dishonest John is Singood; he uses an inebriated little genie to do his dirty work. When it turns against him, D.J./Singood takes a scimitar to genie and instead of slicing him in half, he winds up duplicating the genie. "Split personality," D.J. comments.
* In ''WesternAnimation/BeavisAndButtHead'', The Great Cornholio makes his appearance whenever Beavis has too much sugar and/or caffeine, and when he comes back to himself (usually in some awkward situation), he doesn't remember Cornholio's actions.
* Dr. Splitz/Splitzy in ''WesternAnimation/CaptainSimianAndTheSpaceMonkeys''. Apart from his MeaningfulName, he's also notable in being TheSmartGuy. Sort of. Dr. Splitz is incredibly intelligent, while Splitzy is an impulsive moron. However, they both seem to share incredible knowledge of electronics and machinery, and Splitzy's irrationality sometimes comes in handy when Dr. Splitz is hesitant. They also actually go back and forth between acting like one person with two personalities and interacting with one another.
-->'''Dr. Splitz:''' Uh, don't you have anything to add, Splitzy?\\
'''Splitzy:''' I ain't talkin' to you!
* In ''WesternAnimation/Ben10Omniverse'', mentally unwell DarkMagicalGirl Charmcaster constantly flips between [[GenkiGirl energetic]], AffablyEvil {{CloudCuckoolander}} and [[WithGreatPowerComesGreatInsanity ruthless magic addict]], with the second personality being encouraged by her [[PoisonousCaptive poisonous captives]].
* In the WesternAnimation/{{Classic Disney Short|s}} "Motor Mania", Goofy plays an average suburbanite who is [[DrivesLikeCrazy a different person behind the wheel]].
* ''WesternAnimation/{{Futurama}}'':
** Parodied in the SoapWithinAShow ''All My Circuits'' in "Beast With A Billion Backs," as Calculon discovers he has a fourth split personality. And that it's having an affair with Monique behind his main personality's back.
** In the episode "[[GoAmongMadPeople Insane in the Mainframe]]," Fry encounters a robot Abraham Lincoln in the robot asylum. The problem isn't that he thinks he's Lincoln, but that he has multiple personalities, all of which are Lincoln. "I was born in 200 log cabins..."
* Flippy from ''WebAnimation/HappyTreeFriends'' has post traumatic stress disorder that led to both multiple personality disorder and schizophrenia combined. His normal self is calm, happy, polite, and friendly, while his other self is a blood-thirsty psychopath that murders every living creature around in the most horrifying ways possible, whose affinity for violence and sheer hatred of all things living is arguably on par with [[Manga/ElfenLied Lucy]]. He also has hallucinations of many versions of his evil self and himself going into battle and savagely massacrating each other. It doesn't get more screwed up than that.
* Dr. Rockso, the Rock n' Roll Clown (he does cocaine) in ''WesternAnimation/{{Metalocalypse}}''. Dr. Rockso is the dominant personality, but amicable troublemaker Leonard Rockstein briefly succeeded in suppressing him just long enough to make his return all the more surprising.
* ''WesternAnimation/SouthPark'':
** In the earlier seasons, Mr Garrison's hand puppet Mr Hat was his other personality and imaginary friend that helped him to deal with sexual abuse and transexual thoughts. Said in "World Wide Recorder Concert":
--->'''Mr Mackey:''' Mr Garrison, are you alright?\\
'''Mr Hat:''' Mr. Garrison isn't here right now...\\
'''Mr Mackey:''' Mkay, Mr Garrison, you're just having a hard time dealing with the memories of your father's sexual abuse, so you've switched personalities to Mr Hat.\\
'''Mr Hat:''' Ooh, good one Sherlock, you figured out all that by yourself?
** However, as is later revealed, Garrison feels traumatized by the fact his father '''didn't''' molest him.
** Parodied in the episode "City Sushi" where Dr. Janus diagnoses Butters with multiple personality disorder, identifying Postman Butters, Fireman Butters, Big Rig Butters, Inspector Butters, [[BreadEggsMilkSquick Porn Star Butters]], and Professor Chaos. Meanwhile, [[MeaningfulName Janus]] in fact does have other personalities. Janus has four personalities in total: himself, Billy, a young boy, a violent, unnamed criminal, and [[spoiler:Lu Kim, the owner of City Wok, who in the end becomes the dominant personality.]]
* Lampshaded/played with in ''WesternAnimation/TheMask'' episode... ''Split Personality''. The character is already two personas in one, but subverts the trope as the second personality can only come out when Stanley puts on the mask and changes. However, in this episode, the mask itself is split down the middle, and Stanley puts on one half. The results were... interesting, with half of his body changed into The Mask and the other half left alone. Both characters were sharing one body at the same time. This leads to some very interesting circumstances as Stanley has to try to hide this while half his body is changed. The other half of the mask? It gets worn by Stanley's old high school bully, who ends up with a psychotic murderous half that even manages to freak out the normal side.
* Coldstone in ''WesternAnimation/{{Gargoyles}}'' as it is made of parts from three gargoyles and their souls are trapped inside him, he has three personalities, two good and one evil.
* ''WesternAnimation/TotalDrama Revenge of the Island'''s cast features Mike, who is labeled "The Multiple Personality Disorder", who has four alternate personalities [[spoiler:(with a hidden fifth one in ''All Stars'')]] that even have their own names. [[spoiler:As of the ''All Stars'' finale, Mike cured himself, erasing Mal from existence and gaining the abilities of the others.]]
** GrumpyOldMan (Chester)
** ForeignExchangeStudent and gymnast from Russia (Svetlana)
** {{Jerkass}} from {{Joisey}} (Vito)
** AwesomeAussie (Manitoba Smith)
** [[spoiler: TheDreaded TokenEvilTeammate (Mal a.k.a. The Malevolent One)]]
* Blitzwing of ''WesternAnimation/TransformersAnimated'', with a face to go with each personality. Blitzwing's weaponry and vehicle modes seem to be tied into his personality (in the only interpersonality conflict he's had so far, his angry and calm faces argued over which vehicle form to scan). The calm face uses some sort of ice missile and a jet form, while the angry face uses a flamethrower and tank form and the crazy face seems to be able to use both - but is not as skilled with either. Prowl actually caught on to this during a battle, and used Bumblebee to annoy Blitzwing so much that he switched from calm/jet to angry/tank -- and promptly fell out of the sky.\\\
WordOfGod gives the personalities the names of Icy, Hothead, and Random respectively. Blitzwing's personalities technically aren't different people; they're just immediate shifts between certain states. As seen in the falling tank incident, he'll often swap depending on his mood/the situation -- you'll never see Icy get angry or Hothead act happy. Though there is the infrequent time that the three states interact with each other as if they were separate people. They once even debated over a vehicle mode choice:
-->'''Icy:''' I will choose this fighter jet.\\
'''Hothead:''' No! The assault tank!\\
'''Icy:''' Jet.\\
'''Hothead:''' Tank!\\
'''Icy:''' Ze Jet.\\
'''Hothead:''' Tank!\\
'''Random:''' Ooh-ooh! Why not scan both?
* Played with in the [[WesternAnimation/LooneyTunes Daffy Duck]] cartoon "The Prize Pest." Daffy is Porky's prize in a radio contest. He claims to be schizophrenic--loving and placid when he's treated nice, but mean and monstrous if he's treated wrong. Daffy is actually yanking Porky's chain with the latter id, to which Porky eventually wises up.

[[folder:Real Life]]
* Anne Heche claims (or at least once claimed) to have multiple personalities.
* UsefulNotes/AmericanFootball legend Herschel Walker is probably one of the most interesting real life cases of DID, as despite the disorder (or, possibly, [[DisabilitySuperpower because of it]]) the man was otherwise the very image of mental and physical toughness. When he was growing up he was actually somewhat overweight, as well as being crippingly shy and having a speech impediment. He was consequently bullied throughout elementary and middle school. The trauma eventually led to him creating an alternate "superhero" persona, which did a truly massive amount of exercise and took up sports as a coping mechanism. These changes would eventually lead him to play UsefulNotes/CollegeFootball at Georgia, where his Olympic level speed and immense size and strength more or less allowed him to [[LightningBruiser run through anyone on the field]], which naturally produced some of the most [[https://www.youtube.com/watch?v=wRVE1TQvGzA spectacular plays]] in the history of the game. Imagine superman playing football, and you get an idea of what it looked like. He wasn't diagnosed with DID until he retired from the NFL and his angry persona suddenly no longer had an outlet.
* Kenneth Bianchi, one half of The Hillside Stranglers, [[ObfuscatingInsanity attempted to set up an insanity defence]]. He claimed to have another personality named Steve Walker and, according to Bianchi, Walker was the killer - Bianchi himself was innocent. He managed to fool a couple of psychiatrists before the whole charade collapsed.
* Probably the most well-known case of DID and the one credited (or blamed) with introducing the concept to the public, is ''Film/{{Sybil}},'' whose story was published as a bestselling novel and adapted into a mini-series starring Creator/SallyField.
* ''Book/TheMindsOfBillyMilligan'' is another non-fiction novel that explores a young man with twenty-three personalities. Milligan was tried for a series of rape-and-abductions in the 1970s and was the first (and to date only) person found not guilty by reason of insanity due to DID.
* There have been several autobiographies written by people with DID; for instance, Nellie Parsons Bean's ''[[https://books.google.com/books?id=oDlq6EtyR8wC&dq=%22My+life+as+a+dissociated+personality%22&printsec=frontcover&source=bl&ots=jG6Ha_RbAf&sig=Y_R015UyfFOxrGfDhIjzPb3V9sA&hl=en&ei=bA34SYyBM6b4tAO336nsDg&sa=X&oi=book_result&ct=result&resnum=1#v=onepage&q=%22My%20life%20as%20a%20dissociated%20personality%22&f=false My Life as a Dissociated Personality]]'', writen in 1908; ''The Flock: The Autobiography of a Multiple Personality'' by Joan Frances Casey (Fawcett, 1992) and ''Book/WhenRabbitHowls'' by the Troops for Truddi Chase. Truddi Chase has also appeared on ''Series/TheOprahWinfreyShow''. Chris Costner-Sizemore, the real [[Film/TheThreeFacesOfEve Eve]], wrote her autobiography in two books, ''I'm Eve'' and ''A Mind Of My Own''. Ann Garvey's ''Ann's Multiple World of Personality'' is an account of everyday living as a non-integrated multiple. There are many more books by and about multiple personality [[http://astraeasweb.net/plural/books.html here]].