Jekyll and Hyde

"I guess we're all two people. One daylight, and the one we keep in shadow."

- Bruce Wayne/Batman, Batman Forever

When a character and his Evil Twin, Evil Counterpart, or Shadow Archetype are really the same guy after all. Or, sometimes, a completely different character is sharing body space with another. The point is, the villain lives inside the hero's body, and therefore hides in plain sight. The hero is trying to catch himself.

If the two personalities are aware of each other, it becomes a case of Gollum Made Me Do It. For a more mundane version, see Mood Swinger. See In Vino Veritas if the change is alcohol-induced. As the Hyde personality's crimes are outside the character's control and, often, the character is unable to stop themselves from becoming evil, this is often a case of being Driven to Villainy.

Sometimes they're not really evil, although ... see Dr. Pedia and Mr. Trope for the Wiki Tropes version of this. Occasionally, this can be resolved (not necessarily favorably) with a Split Personality Takeover, or with a Split Personality Merge that reconciles both sides into a healthy whole. Also, the "Jekyll" side isn't neccesarily "good" either; after all, the Trope Namer was selfish enough to keep drinking the stuff, and invented it for pretty bad reasons.

Comes, of course, from The Strange Case of Doctor Jekyll and Mr. Hyde, by Robert Louis Stevenson. It used to be a Twist Ending, but it no longer surprises anyone.

The real life example of Deacon Brodie (cabinet-making pillar of the church by day, burglar by night) is said to have inspired Stevenson.

Not to be confused with the stage musical of the same name.

Anime and Manga

 * Kenshin and Battousai in Rurouni Kenshin.
 * Kyo and Kyoshiro in Samurai Deeper Kyo.
 * Magical Project S: Misao Amano's normal self is that of a stereotypical Shrinking Violet friendless, blue-haired Ill Girl. However, this persona falls away when she's transformed into Pixy Misa, the manifestation of her deeply repressed id: an egomaniacal jealous Dark Magical Girl trickster.
 * Inverted with Lucy/Nyu from Elfen Lied. Lucy, the evil counterpart, is actually the original character (sort of), while a blow to the head caused her to go into passive, non-lethal mode.
 * After the protagonist of Death Note pulls a Memory Gambit, he devotes himself to catching Kira, not being able to remember that he himself is Kira. The instant he regains his memories, he reverts to his original personality and begins killing once more.
 * Gankutsuou has The Count of Monte Cristo possessed by the titular demon which completely submerges his original good personality as Edmond Dantes.
 * Tohno Shiki from Tsukihime; when either his life is in extreme danger or he is confronted with something non-human he loses grip on his consciousness and becomes the amoral sociopathic killer Nanaya Shiki, who is a highly skilled assassin. Slightly subverted, though, in that
 * Mnemosyne subverts this in its penultimate episode. Rin, who was sucked into a jet engine, and presumably got her memories mixed up from having her brain turned into a shake, is seen working at a Mega Corp by day and killing other immortals and collecting their time spores by night. Mimi even lampshades it. However, it turns out that
 * In D Gray Man, this is the case with Tyki Mikk and quite possibly the rest of the Noah.
 * Nah, just Tyki (who 'loves humans'); but his mind remains constant between sides, and he gave his little friend the silver off a murdered exorcist's coat as a present. If Allen had gotten it, the plot might have run a bit differently....
 * Also, White Tyki appears to be effectively dead. His identity took a serious scramble back when Allen thought he'd cut the evil out of him and got a really superpowered especially evil side instead. Surprising pulled himself back together, but he's different.
 * The Noah are activated out of normal humans, whenever a seat is left unfilled by a death in the family, and for the most part memory is not continuous from incarnation to incarnation, but those persons are still pretty much entirely subsumed into the Noah identity once activated.
 * Whether Adam the Millennium Earl and the Fourteenth have died and recorporated before is not clear; very possibly they haven't. Road is over thirty five now; it's possible Adam has kept that rakish young face for thousands of years. (And covered it with a grinning balloon thing in a goofy hat about as long. Mysteriously.)
 * Hellsing has Yumiko Takagi, sweet and gentle nun, kept on hand by the Vatican's secret team of assassins for her alternate personality Yumie, who is a berserker killing machine (and darn good with a katana).
 * Harumi Chono from Paranoia Agent. Tutor for Ichi by day, a prostitute named Maria by night. The way they communicate with one another? Leaving messages on their answering machine for each other.
 * Allelujah and Hallelujah in Mobile Suit Gundam 00.
 * Zettai Karen Children has Mirage, who is also Phantom Daughter. Both personalities are hiding in and from Yuuri, AKA The Doll, an ordinary schoolgirl "built" for infiltration that they are spending an increasing amount of time in, to their boss' displeasure. Additionally, there's a fourth personality that the other three are unaware of.
 * In Kämpfer, Akane is a sweet, shy, bespectacled girl who often hangs out in the library. When she turns into a Kämpfer, then she becomes a real mean, foul-mouthed, trigger-happy bitch with a pair of pistols.
 * In Project ARMS, . Alice herself is split into "White Alice" and "Dark Alice".
 * Naraku and his evil human self, Onigumo, in Inuyasha.
 * Don't forget about Suikotsu and his evil personality.
 * In the manga 666 Satan (or O-Parts Hunter in the US), the main character Jio has Satan inside of him. Satan comes out when Jio's or his friend's lives are threatened.
 * Rosario to Vampire has Moka Akashiya, a shy, well mannered girl who is not always confident. Her true self is thuggish brute of a vampire who can litterally kick the snot out of just about anyone.
 * Amuri in Star Ocean has Perrier/Vernier La Mer. Perrier is the real personality who, as a result of torturously cruel parenting, subconciously created Vernier as a defense mechanism and even referred to her as her older sister. When seeing her reflection, Perrier would see Vernier looking back and talking to her, always taunting and insulting her. Vernier does not take full control of Perrier, though, until she is pushed into a state of extreme terror.
 * Jūgo of the Scales in Naruto is a Gentle Giant who lives in constant fear of what he will do when his bloodline transforms him into his Curse Seal self.

Comic Books

 * The League of Extraordinary Gentlemen includes an aged, monstrous Hyde as a member. Jekyll is now thin and sickly while Hyde is a red-skinned, bulked up giant monster, and its implied that he was feeding off of Jekyll's energy.
 * The "A Murder In Paradise" Story Arc of Cable & Deadpool has Deadpool looking for the murderer of an Osama bin Laden-esque figure who took sanctuary in Cable's island country. Guess who did it and can't remember.
 * Bruce Banner and his more famous darkside The Incredible Hulk.
 * In the Marvel 1602 Elseworld, David Banner gets transformed into the Incredible Hulk. One of the follow-ups reveals a twist: David works for the new king of England, James Something-Or-Other, and is evil, sadistic and altogether not a nice bloke at all. The Hulk, on the other hand, is noble and intelligent.
 * The supervillain Mr. Hyde subverts this trope in a couple of different ways. While the "Hyde" persona is a sadistic Complete Monster, the "Jekyll" persona is both an unethical scientist and a perverted Dirty Old Man to boot. Both personas are completely aware of one another, and they happen to get along just fine, although "Hyde" is the dominant personality.
 * Harvey Dent, a.k.a 'Two-Face', of the Batman mythos has this going on as well, with the split represented by Harvey's own split face; his unblemished, handsome right side representing the good, noble District Attorney Harvey Dent, and the scarred, mangled left side representing the malevolent, vicious criminal Two-Face. In his case, the choice between 'Jekyll' and 'Hyde' depends on the results of a coin toss, with good or bad triumphing depending on which side the coin comes down on.
 * This is singly most obvious in his debut apperance, where distinct similarities are drawn between him and the story. In fact, his appearance was inspired by a poster for the Spencer Tracy film.
 * The Dark Knight Returns turns this on its head.
 * The Green Goblin is sometimes, and to an extent originally, depicted as a split personality of the milquetoast scientist Norman Osborn in Spider-Man. The main difference is that Osborn is a Manipulative Bastard, while the Goblin is a Ax Crazy psychopath. Since he came Back From the Dead, Osborn had been more or less in control and became the Goblin willingly and for shitz and giggles, but recently he's started losing it again.
 * Of particular note is when he had a total breakdown while he was Captain America, and when they took his mask off he had Green Goblin paint on underneath...
 * Speaking of Spider Man villains The Lizard also counts.
 * In X-Men, Sauron (no, not THAT Sauron) has this kind of relationship with his alter-ego, Karl Lykos.
 * The Ventriloquist and his puppet, Scarface. Thought most people (including some writers and readers) act as if Scarface were actually alive.
 * In Daredevil, Typhoid Mary is the split personality of the otherwise nice and peaceful Mary Walker.
 * She also has the Bloody Mary personality.
 * Alpha Flight's Aurora switched between a free-spirited superhero personality and that of a highly repressed Catholic school teacher.
 * Kyle Rayner's vast powers were not being fully harnessed, so they formed a shadow entity called Oblivion.
 * Is dat sum Parallax?
 * Pretty much the exact same situation with The Sentry and The Void at Marvel.
 * Hal Jordan had an arc where his...conjured body was warping between Spectre, the white-templed Evil Hal run by the fear entity Parallax, which is what he looked like when he did the genocide thing, and his own mixed-up personality, which looks like he did when he was a spry young pilot and at the top of his superheroing game. Often the head and shoulders of one entity will come thrusting out of one of the others. It verges on squicky. They argue a lot. Specter only possessed Hal hoping he could purge Parallax, but now it looks like Parallax might just be getting the Specter's considerable powers, and the Specter and Hal can't see eye-to-eye enough to work well together.
 * Ultimately Parallax is overwhelmed, the Spectre ditches Hal to go find another host just when it looked like they could really beat Parallax, the remaining two split, and Hal winds up back in his body (which had been preserved where he sacrificed himself in the sun), which de-ages to match the look of his soul, and he's a good guy again. Just in time for the world to go to hell.
 * Mark Shaw aka Manhunter was constantly tracking a serial killer named Dumas, guess why he could never find him.
 * In Grendel, what starts out at Hunter Rose's supervillain-identity gradually evolves into a sort of Mr. Hyde alter-ego, which jumps from host to host (or do the "hosts" just share the same psychosis?) over many generations. The Grendel persona best conforms to this trope with the third "host", Brian Li Sung, whose personal journal contrasts the guilt-ridden ponderings of Brian and the emerging rants of the Grendel within.

Film

 * The 2006 film A Scanner Darkly has the main character hunting down a drug dealer who is in fact himself, having developed split personalities from the drug.
 * The Amicus Studios version, I Monster followed the original novel quite closely but changed the character's names in the hope of catching the viewers by surprise.
 * from Fight Club.
 * Lampshaded by Marla: "You're Dr. Jekyll and Mr. Jackass."
 * Dr Jekyll and Ms Hyde.
 * Me, Myself and Irene had this with Jim Carrey playing two guys in one- nice cop Charlie and bad cop Hank.
 * Repo! The Genetic Opera has Nathan, doting father by day, Repo Man by night.
 * Eh... Somewhat. Nathan's seems to be a more intentional shifting between identities rather than a real split personality. This can be seen during the scene where he's talking to Shilo as Nathan while performing his job as Repo Man at the same time.
 * Zdunich has referred to the character(s) as "Doctor Nathan and Mr. Repo Man", so Word Of God... er... at least considers that reference accurate?
 * in Psycho.
 * Is the spoiler bar really necessary?
 * Alfred Hitchcock doesn't want us to spoil the movie for others.
 * in Hide and Seek.
 * The Two Faces of Dr. Jekyll has an interesting variation. Dr. Jekyll is hirsute, unkempt, ill-tempered and mannerless; Hyde is clean-shaven, well-dressed, well-mannered, and charming. But Jekyll's still basically a decent guy, and Hyde is thoroughly depraved and evil.
 * Angel Heart (1987) with Mickey Rourke.
 * Bergman's 'Persona'. The dynamic between Elisabet and Sister Alma; the strange scenes in which one turns the other's head towards her; the reaction of Mr Vogler to Anna.
 * Julius Kelp (Sherman Klump in the remake) and Buddy Love in The Nutty Professor.
 * Jekyll and Hyde... Together Again had Mark Blankfield going from humble doctor to drugged out sex crazed swinger.
 * Quaid is actually an implanted personality of the villain Hauser. Maybe.

Literature

 * , though you probably know this already.
 * In Neil Gaiman's American Gods it is revealed at the end and hinted throughout that the paired Slavic gods Czernobog (which translates to Black God) and Bielebog (White God) are a Jekyll and Hyde.
 * In the book version of Dexter, the lovable Serial Killer is motivated to kill by a sort of being/other personality, the Dark Passenger.
 * In the Xanth book Crewel Lye,
 * Even though it's the Trope Namer, the book The Strange Case Dr Jekyll and Mr Hyde is not really an example of this. Dr Jekyll deliberately created Mr Hyde and they were not at all antagonists, until Dr Jekyll eventually permanently became Mr Hyde. The protagonist is a friend of Dr Jekyll who investigates his sudden disappearance.
 * Jekyll's transformation is inverted and averted by Julian Advent of the Nightside series, who faced the same choice as Jekyll when he discovered a similar formula, but chose to drink the version that brought his Good side to the fore, making him The Cape instead of this trope.
 * Nabokov's Lolita has the whole dynamic between Humbert and Quilty leading to the frankly quite trippy scenes at the end, the chase, and especially the murder.
 * Odetta and Detta in The Dark Tower.

Live Action TV

 * Scorpius's suicidal program inside Crichton's head in Farscape.
 * Brainwashed Geordi used as an assassin on Star Trek the Next Generation.
 * One episode of Star Trek Voyager has  develop a villainous split personality which he is unaware of as a result of.
 * A really beautiful Deconstruction is the British series Jekyll.
 * Niki and Jessica from Heroes.
 * Season 6 of Dexter has  turning out to be just one person, they even try to Sixth Sense the twist for nine episodes. It was painfully obvious.
 * Buffy the Vampire Slayer.
 * More obvious, Angel and Angelus from Buffy the Vampire Slayer and Angel. Though at different times in both series that varies between Jekyll and Hyde and Enemy Within. It all depends on whether Angel simply becomes evil when he loses his soul (as his Buffy appearances and Angel's fifth season implied) or if losing his soul replaces Angel with the demon soul of Angelus (as it seemed to be in Angel's fourth season).
 * Except that Angel losing his soul always leads to the demon Angelus taking over, because Angelus is always there. Otherwise Angel would, at least, not be able to vamp out, and probably keel over dead, being a corpse, without the demon animating him. For proof, see the season 2 finale of Angel. When he tries to vamp out on Pylea, . Of course, Angelus, particularly according to that example, is a blend of the demon's personality and sadism with Angel's memories and brain(but not his soul). When Angel loses his soul, it's gone, and all that's left is Angelus. All of those incidents where he's evil are Angelus.
 * There's also the Series Three episode Beauty and the Beasts, which features a high school student drinking a chemical potion that turn him into a monster who attacks anyone who gets too close to his girlfriend.
 * Julia Jekyll and Harriet Hyde had the main character Julia Jekyll turn into a hairy monster called Harriet Hyde uncontrollably.
 * A show called My Own Worst Enemy features a man leading a double life. His normal side is Henry and his alternate ego (that he doesn't know about) is the spy Edward, which is most likely an allusion to the original Dr. Henry Jekyll and Edward Hyde. Reverses the usual Jekyll/Hyde dynamic in that
 * Also subverted. While Edward is arguably the edgier of the two personalities, he's not actually evil.
 * Ace Lightning has Random Virus, who has two personalities, good and evil, signified by his cyborg eye being green or red, respectively. He doesn't seem to have much control over whether he's good or evil, although Ace managed to turn him good temporarily by reminding him that he was a Lightning Knight, and therefore a 'good guy'.
 * Playing this trope painfully straight is Darkstrike from Birds of Prey: he's a vigilante hunting after the Creeper, the Serial Killer who killed his girlfriend.
 * From Where In Time Is Carmen Sandiego was a girl named Jacqueline Hyde, who jumped from sweet, innocent schoolgirl to raving, snarling harpy at the drop of a hat.
 * Davis Bloome/Doomsday.
 * Adam Worth from Sanctuary is said to be the in-universe explanation for the novel. Neither personality is particularly stronger, but unlike most examples, both sides work in tandem.
 * Supernatural: Kind-and-gentle human Sammy, arrogant-and-violent demonic Sammy. And then there is soulless robo Sammy...
 * Doctor Who has
 * Mesogog and Anton Mercer from Power Rangers Dino Thunder. Eventually Mesogog splits himself off from Mercer because he gets fed up with sharing. It frees the Rangers to not hold back against him, but he becomes even more effective due to being able to act more often and not just when he surfaces.

Music

 * "Sacrifice" by Disturbed is about this trope, along with themes of "My other side is going to hurt you".

Tabletop Games

 * The Alchemist in Pathfinder has this as a class option. The character researches and creates a unique infusion that, when taken, changes the character's abilities, personality and alignment.
 * Magic the Gathering, in its Gothic horror-themed Innistrad expansion, introduced "Civilized Scholar", a double-faced card that transforms into "Homicidal Brute". He was actually named "Jekyll and Hyde" as a placeholder in the early designs for the set.

Video Games

 * Marcus Kane (Roadkill) and Needles Kane (Sweet Tooth) of the Twisted Metal series.
 * Daniel and in Manhunt 2.
 * Emil from Tales of Symphonia Dawn of the New World has two personalities. First, there is his normal, timid, self-effacing personality. Then there's his "Ratatosk Mode," which is significantly more aggressive, to say the least.
 * in the first Mega Man Star Force.
 * Xenogears -
 * In the second Summon Nights for GBA, one of your Guardian Beasts is a trashtalking demon who claims to have been possessed by her angelic sweet side. Subverted in the matter that the demon is the leading personality, with the angel being the hidden "Hyde".
 * Kind of easy to miss, but Quest for Glory had
 * It turns out that, in The Suffering and it's sequel,
 * Angel Starr from the first Ace Attorney game, complete with Peek a Bangs moving from one eye to another depending on whether she's sweet or sour.
 * Doshin, the kind, benevolent, helpful giant, and Jashin, the evil, sadistic, vicious version, in Doshin the Giant.

Web Comics

 * Chastity and Prixen, Martina and Sweater Puppy in The Magnificent Milkmaid.
 * Anna and Susan in Sire. Indeed, they obsess over the original Stevenson work, and are even.
 * of Tessa Stone's Hanna is Not a Boy's Name! has a Jekyll and Hyde disorder of sorts.
 * When of Homestuck is stoned, he's one of the sweetest, most goofy Love Freak characters in the whole thing. But when he gets sober...

Web Original

 * This is how Spoony and  are portrayed in the That Guy With the Glasses anniversary special Kickassia. (Note that this is subject to Negative Continuity.)
 * Flippy from Happy Tree Friends.

Western Animation
"Jade (pointing to amoral Jackie): You're evil! EVIL!
 * In the Transformers universe, the Autobot Punch adopted a Decepticon personality as Counter-Punch, so as to play a double agent. He has lost some sense of self-identity because the Counter-Punch personality takes over, leaving him with a sense that he's missed out on the past hour or so.
 * It also happened in Beast Machines, with Savage and Noble. Savage is a blind, insane, vicious dragon, while Noble is an intelligent and cunning wolfbot.
 * Several times in Jackie Chan Adventures is Jackie split into a good and bad side, usually via the Tiger talisman. Of course these two sides are the same person and represent the balance in all humans of a good and bad side. Ironically, this occurs in one episode in which Jade is performing in a play about Jekyll and Hyde.
 * It's not really "good" and "bad" so much as "moral pacifist" and "amoral badass":

Uncle: Not evil. Only misguided."


 * Spider-Man the Animated Series - Norman Osborn and the Goblin; unlike most depictions, this version of Osborn was a decent guy (or at least trying to be one), while the Goblin was as homicidal as ever.
 * Catscratch has Gordon, who is allergic to broccoli and turns into a monster if he even touches it. Subverted that he's still himself after the reaction.
 * Morph from the X-Men animated series, after coming Back From the Dead, often wavered back and forth between his normal, "Jekyll" self and a semi-undead "Mr. Hyde" alter-ego who blamed the X-Men for leaving him behind on a failed mission. Of course, it turned out he was mind-controlled by the season's Big Bad, but the effects didn't leave him for a good while afterward.
 * At one point, he even hides out with a theater troop, where he performs "Jekyll and Hyde", using his shapeshifting powers to play both roles.
 * The 1950 Goofy cartoon "Motormania" features Goofy as the mild-mannered, friendly Mr. Walker. However, whenever Mr. Walker gets into his car, he becomes the ill-tempered, violent, and reckless Mr. Wheeler.
 * The Superhero Episode of Jimmy Two Shoes featured a large, green monster that constantly attacked Lucius. It was eventually revealed to be Samy, who was constantly transforming thanks to one of Heloise's potions.
 * Mary Shelley's Frankenhole has the Jekyll and Hyde, whose serum causes . Victor also ridicules him for being his own monster.
 * "Jekyll, Jekyll, Hyde, Jekyll, Hyde, Hyde, Jekyll! "Jekyll, Jekyll, Hyde, Jekyll, HYDE!!!"

Real Life

 * According to Colin Willson's History of Murder, the Thugee cult of India were sort of a Truth in Television example of this achieved through brainwashing, as they would lead normal lives most of the time, but then commit mass murder when seized by bloodlust. Wilson includes comments from Thugs to the effect that while generally they treated their killings as committed as within a dream, many felt that this murderous life was the real one rather than their respectable life.
 * "It wasn't me, it was the Black Sleep of Kali!"

Other

 * TV Tropes: Sugar Wiki and Darth Wiki.