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[[quoteright:350:[[ComicBook/IdentityCrisis1998 https://static.tvtropes.org/pmwiki/pub/images/Spider-Man_Identity_Crisis_1870.jpg]]]]
[[caption-width-right:350:''Who'' was that strange, masked man?]]

->'''Betty Brant:''' Wait, wait, is that... do you think that's Spider-Man?\\
'''Ned Leeds:''' No, no, no, it's like a European ripoff version of him. I was actually reading about him the other day, it's not him.\\
[...]\\
'''Betty:''' What's his name? What's his name?\\
'''Ned:''' Umm... Night Monkey.
-->-- About Peter Parker's new look, ''Film/SpiderManFarFromHome''

This is when your hero decides that, for whatever reason, they are going to create an additional superhero alter ego besides the one they already have. This is often, but not always, due to necessity or due to a superhero mid-life crisis. This new identity is often less well known than their original one. Maybe it's to do things that their alter ego can't be seen doing. Maybe they dress up as another preexisting hero to cash in on their reputation. Sometimes it's just a stylistic name change. Or sometimes their alter ego is being hunted by cops and they need to crimefight while getting their name cleared. Whatever the reason, the hero now has another crime fighting alter ego in addition to their original one.

Related to LegacyCharacter, BecomingTheMask, SecretIdentity, SecretIdentityIdentity, MultilayerFacade.
----
!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* ''Manga/DeathNote'''s L, the greatest detective in the world, also assumes the identities of the second and third greatest detectives, respectively Eraldo Coil and Deneuve. This is useful for him because anyone who wants to figure out L's identity usually will try to hire Coil or Deneuve.
* In ''Anime/DragonBallZ'', Gohan becomes a crime fighting superhero. At first, he just turns into a Super Saiyan and is referred to as "the Golden Warrior". Later, Bulma builds him a tokusatsu hero outfit and he adopts a second moniker, "The Great Saiyaman". Eventually during the 25th Tenkaichi Budokai, he ultimately reveals to the other characters that he's both.
* In ''Anime/FZeroGPLegend'', Captain Falcon [[spoiler:is at one point killed. After that, the mysterious racer Berserker joins Dark Million. It is eventually revealed that Berserker was actually Captain Falcon, alive, and in disguise, spying on Dark Million.]]
* ''Anime/{{Medabots}}'': Hikaru Agata (Henry) with his two alter egos, the [[PhantomThief Phantom Renegade]] and [[TheAce Space Medafighter X]]. The two have alter egos have the same haircut as Hikaru and they both use almost identical masks, one being white, the other being gold. Space Medafighter X also serves as a MultilayerFacade for the Phantom Renegade because Hikaru wears ''two'' masks.
* Not exactly super, but Char from ''Anime/MobileSuitGundam'' is actually the secret identity of Casval Rem Deikun, who seeks revenge on his father's murderers by posing in their army as his dead friend Char. Then, in ''Anime/MobileSuitZetaGundam'', he takes a second secret identity as Quattro Bajeena. This one is completely ineffective thanks to his PaperThinDisguise, and by mid-series his identity as Char is essentially an OpenSecret amongst the members of the AEUG and the enemy forces' leaders. He ends up revealing his true identity to the world at his publicly-broadcast address to the Federation assembly at Dakar.
* In ''Manga/MyHeroAcademiaVigilantes'', the vigilante Stendhal is introduced killing villains in what he believes makes up for the heroes' failure for removing them. He is later revealed to be [[spoiler:Chizome Akaguro]], who would take the identity as [[spoiler:the Hero-Killer Stain]] in [[Manga/MyHeroAcademia the main series]].
[[/folder]]

[[folder:Comic Books]]
!!!Marvel:
* Hank Pym, the original ComicBook/AntMan, has a habit of juggling multiple superhero personae (i.e. Giant-Man, Wasp, Goliath, Ant Man, Yellowjacket and even, at one point, his real name). Some continuities explain this as him having identity issues.
* ComicBook/CaptainAmerica went undercover as The Captain on two different occasions.
** This was because the Government demanded that he work exclusively for them, and when he refused, they forbid him from using the Captain America identity, which they legally owned. They gave the identity to another hero, Super Patriot, who later ended up trading costumes with The Captain and being renamed US Agent.
** His ComicBook/UltimateMarvel counterpart spent some time as that universe's ComicBook/BlackPanther.
** In the 1970s he becomes disillusioned with the U.S. government and takes on the new identity "Nomad". This identity would later be taken by Jack Monroe who had previously been Bucky to the 50's anti-communist Cap.
* ''ComicBook/{{Hawkeye}}'': Clint Barton usually goes by Hawkeye, but he's also been Ronin (the second Ronin in the Avengers) and Goliath. Plus he tried out the Captain America identity after the death of the original, but decided it wasn't for him.
** In ''ComicBook/MightyAvengers2013'', a powerful guy joins the team with the first disguise he found, a ridiculously colored "Spider Hero" outfit. When he clarifies he'd be happy to wear anything hiding his identity but better looking, Luke Cage hands him a box of old Clint Barton's stuff, so the reader still doesn't know his first identity, but he becomes the new Ronin. He is eventually revealed to be [[spoiler:Blade]].
* ''ComicBook/TheIncredibleHulk'':
** Early in Creator/PeterDavid's run on ''ComicBook/TheIncredibleHulk1968'', the Hulk is caught in the middle of a gamma bomb explosion and presumed dead, but he ends up hiding out in Las Vegas as a mob enforcer calling himself Joe Fixit. This ends up being the gray Hulk's all-but-official name.
** In ''ComicBook/Hulk2014'', during the ''Omega Hulk'' storyline, the superintelligent Hulk took the name Doc Green.
* ''ComicBook/MoonKnight'' himself has been known to operate as both Moon Knight (the violent and vengeful gadgeteer vigilante) and Mr. Knight (a violent intellectual ''sarcastic'' vigilante).
** Inverted by the same character, who has multiple civilian identities. As cabby Jake Locksley, he can keep an ear to the ground, and as Steven Grant he's often invited to high-society functions. His actual birth name is Marc Spector. Interestingly, he actually suffers from DID (aka "multiple personality disorder") and his identities are his alter egos.
* Ronin was intended to be an example (he was supposed to be Daredevil in disguise) but ExecutiveMeddling changed Ronin's identity. [[spoiler:It still remained an example, as Ronin was revealed to be Echo, a deaf former AntiVillain.]]
* Comicbook/SpiderMan did this as an entire group of heroes. When Spider-Man was accused of murder during the ''ComicBook/{{Identity Crisis|1998}}'' storyline, he temporarily adopted four other costumed identities to allow him to continue fighting crime without appearing as Spider-Man: Hornet, Prodigy, Ricochet and Dusk. By having 4 different identities (2 of which he used to go undercover as a "supervillain"), Spidey could freely discard any one that got compromised while continuing to act as a hero. Eventually these personae were adopted by other heroes, creating The ComicBook/{{Slingers}}.
** Then there’s the times when Peter has had to hero without his usual webs, donning makeshift costumes and identities like “The Bombastic Bag Man”.
* In the ''ComicBook/{{Thunderbolts}}'' series, the original premise was that the Masters of Evil took on new (faux) super-hero identities and presented themselves as a replacement for the Avengers.
* During Flash Thompson's time as ComicBook/{{Venom}}, he relocated to Philadelphia and came up with some other identities to hide his symbiotic status. One of them was "Hail Mary, the Mother Superior of Punishment", a vigilante nun, because frankly why not at this point.
* In the ''New X-Men'' series written by Creator/GrantMorrison, the friendly Chinese dissident mutant Xorn (who was explained to require a mask at all times due to the nature of his powers) was revealed to be ComicBook/{{Magneto}} in disguise all along, who after crippling Professor X proceed to take a giant, [[ANaziByAnyOtherName Nazi-esque]] leap over the MoralEventHorizon. Attempts were made by higher ups and other writers to RetCon this as soon as possible, leading to a ContinuitySnarl, wherein Xorn was explained to be [[MultiLayerFacade Xorn pretending to be Magneto pretending to be Xorn]]. And then later on, another Xorn showed up who was the brother of the impostor Xorn. For their part, Morrison maintains that they always intended Xorn to be Magneto.
* During the ComicBook/XMen storyline "The Twelve", {{ComicBook/Apocalypse}} has a new Horseman, Death, who fights and kills Wolverine. Death turns out to be [[spoiler:the real, albeit brainwashed, Wolverine. The Wolverine he killed was a Skrull imposter.]]
** Other characters with existing identities who became Horsemen include Angel (Death, afterwards he'd adopt the name Archangel), Plague of the Morlocks (Pestilence), Caliban (Death and Pestilence at different times), Hulk (War), Deathbird (War), Gazer (War), Sunfire (Famine), Polaris (Pestilence), Gambit (Death), and Psylocke (Death).

!!!DC:
* In ''ComicBook/FiftyTwo'', Lex Luthor thinks ComicBook/{{Superman}} has done this and become the new hero Supernova. After looking into it, his subordinates come to the conclusion it's actually Superboy. Of course, they're all wrong. It's [[spoiler:ComicBook/BoosterGold]].
* ''ComicBook/{{Batman}}'':
** Subverted. Bruce Wayne took on the identity of "Starman" for an issue in 1951 when a dose of Fear Gas (from Professor Milo this time) made him terrified of bats. In the Post-ComicBook/ZeroHourCrisisInTime version of the story from ComicBook/{{Starman}}, it was [[spoiler:Doctor Mid-Nite]].
** ''ComicBook/TheSupergirlBatgirlPlot'': Since Batman does not yet know ComicBook/{{Batgirl}}'s real identity, Batmite tries to trick him into believing Batgirl is ComicBook/{{Catwoman}}'s second secret identity. Nonetheless, Batman is not fooled because both women have different eye colors.
** ComicBook/{{Nightwing}} once adopted the alternate superhero identity of the Target when it became inadvisable for him to operate as Nightwing. He'd previously had the identity of Robin.
** Before being forced to take up a new superhero identity and adopting ComicBook/RedRobin on a more consistent basis Tim Drake temporarily used the alias in the pages of ''ComicBook/Robin1993'' after suffering burns to the back of his head and neck. He also used "The Spectacular Sunbird" for about a day when he realized that in his hurry he'd forgotten to remove a wig he was using before changing into most of the Robin costume.
* ComicBook/MartianManhunter: Since he's a ShapeShifter who has been on Earth since 1955, J'onn has used a number of identities, including the superheroes The Bronze Wraith in [[MediaNotes/TheBronzeAgeOfComicBooks the seventies]] and Bloodwynd in [[MediaNotes/TheDarkAgeOfComicBooks the nineties.]] Although [[TheRealRemingtonSteele there was a real Bloodwynd]].
* ''ComicBook/{{Supergirl}}'':
** Before her existence was revealed to the world in "ComicBook/TheUnknownSupergirl", Pre-Crisis ComicBook/{{Supergirl}} sometimes operated as the heroine "Mighty Maid".
** ''ComicBook/Supergirl2005'': Supergirl briefly took up the "Flamebird" moniker during the "Candor" storyline, alongside Power Girl as Nightwing.
** In ''ComicBook/AdventureComics'' #350, Miss Terious and Sir Prize replaced ComicBook/{{Superboy}} and ComicBook/{{Supergirl}} as members of the ComicBook/LegionOfSuperHeroes when the Earth was covered in Kryptonite, eventually revealing themselves to be [[spoiler: Dream Girl and Star Boy, who had previously left the team]].
** In "ComicBook/TheUnknownLegionnaire", Supergirl became "Unknown Boy" as posing as a nameless Legion's ally.
* ''ComicBook/{{Superman}}'':
** In "ComicBook/LuthorUnleashed", Lex builds an armor and creates another super-villain identity called the Mystery Marauder to commit crimes across the world of Lexor.
** Back in the early '90s, Superman comic books had a super-antihero named Gangbuster. After a year, he turned out to be [[spoiler:Superman, with a trauma-induced separate personality]].
** In the Silver Age, Superman would sometimes shrink himself and Jimmy Olsen to visit the bottle-city of Kandor.[[note]]A former Kryptonian city, inhabited by former Kryptonians, that had been shrunk by Brainiac 5.[[/note]] There, they would sometimes adopt the personas of Nightwing[[note]]the names were based on Kryptonian mythology and ''this'' Nightwing predated the more famous Dick Grayson version by a couple of decades; it was and may still be canon that Dick chose the moniker at least partially ''because'' of the Kryptonian hero[[/note]] (Superman) and Flamebird (Jimmy), a pair of costumed heroes along the lines of Batman and Robin (Superman lost his superpowers while in the city but was still muscular and athletic, and he had some gadgets to help him out as well).
* ''ComicBook/WorldsFinest1941'':
** Issue #89 revolves around a new superhero named Lightning-Man who keeps showing up Superman. Eventually, the heroes realized a small piece of Green K gave Clark amnesia, so he constructed the new identity himself to help people.
** Issue #119 revolves around a superhero named "Tigerman", who turns out to be...Superman acting as a clumsy new hero so bad guys will capture him and take him to their hideout.
** Issue #155 revolves around a new hero named Nightman who teams up with Superman instead. It turns out Superman had hypnotized Batman into taking the identity to give him a challenging case to solve.

!!!Other:
* In the ''Big Bang Comics'' universe, Knight Watchman's sidekick -- Kid Galahad -- inherited the role of Knight Watchman. He operates both as the publicly known and liked Galahad during the day, and as the mysterious and feared Knight Watchman at night.
* Happens to a few characters in the ''ComicBook/DisneyDucksComicUniverse'':
** Donald, Fethry and Daisy are all superheroes as the Duck Avenger (Paperinik), the Red Bat and Super Daisy (Paperinika) respectively, and also work as spies for Scrooge's Private Intelligence Agency.
** Being a continuation of the "classic" Paperinik stories, ''ComicBook/PaperinikNewAdventures'' already has his two Paperinik and PIA agent identities... Then a ''ComicBook/DoubleDuck'' story confirms that it's set in the same universe as ''ComicBook/PaperinikNewAdventures'', adding a ''third'' identity. This actually got {{Foreshadowed}} in an omake where he accidentally took his superspy tuxedo (Double Duck) instead of his superhero costume (Paperinik), and when Paperinik's Extransformer Shield was spotted in a ''Double Duck'' story.
-->"Sometimes I envy other super-heroes who have to manage ONE single DOUBLE identity!"
* ''Comicbook/{{Supreme}}'' had a version of Superman's Nightwing identity, when he and Diana Dane entered the Prism World as Doctor Dark and Duskwing, based on Professor Night and Twilight.
[[/folder]]

[[folder:Fan Works]]
* ''Fanfic/CheshireMiraculousLadybug'': Marinette has ''several'' identities at her disposal, depending upon the Miraculous that she uses.
** Plagg: ''Cheshire''
** [[spoiler:Trixx]]: [[spoiler:''Kitsune'' or ''Cheshire Foxy Mode'']]
** [[spoiler:Kaalki]]: [[spoiler:''Knightmare'']]
** [[spoiler:Mullo]]: [[spoiler:''Multicat'']]
** [[spoiler:Plagg+Kaalki]]: [[spoiler:''Manecat'']]
** [[spoiler:Plagg+Liiri]]: [[spoiler:''Griffin'']]
** She is also the [[spoiler:Temporary Turtle Hero Bixi]].
* Xander Harris in ''[[https://www.tthfanfic.org/Story-21621/CrazyDan+The+Child+of+Rao+Book+II.htm The Child of Rao: Book II]]'' is a kryptonian superhero and has another identity as an Amish [[WesternAnimation/StaticShock bang baby]] who's an ActualPacifist and only participates in search and rescue work for the Justice League.
* ''Fanfic/ConsequencesMiraculousLadybug'':
** In ''RUNNING AMOK'', Lila (having been both the akumas Volpina and Chameleon) is given the Peacock Miraculous to become Pavona. After the heroes defeat her and reclaim her Miraculous, Adrien/Cat Noir uses it to become Catbird.
** In ''EXPOSED'', Adrien uses the Fox Miraculous to become Kitsune in order to save Ladybug's SecretIdentity, who had been exposed by Lila Rossi.
** In ''CUTTING THE STRINGS'', Max (the Horse hero Pegasus) and Kim (the Monkey hero King Monkey) are given the Ladybug and Black Cat Miraculous respectively after Marinette and Adrien are captured by an akumatized Lila. They use them to become Bug-a-Boy and Jaguaro.
** In ''SUN'S WRATH'', after Adrien is akumatized, Nino (the Turtle hero Carapace) is given the Black Cat Miraculous to become Calico.
** In ''CAGED'', Juleka (the Tiger hero Purple Tigress) becomes the Black Cat Ahkari when Adrien cannot transform while held in Cage-Master's cage.
* ''Fanfic/HeroChat'': Officially to the public, both Chloé and Kagami stepped down as Queen Bee and Ryuko respectively after their identities were exposed. In truth, both of them still use the Bee and Dragon Miraculous as Honey Bee and Arashi respectively. The only ones that know this are the rest of Team Miraculous.
* ''[[Fanfic/ALadysScout A Lady's Scout (and the Salt Within Her Soul)]]'': Marinette's plan to punish the ''former'' temporary heroes who betrayed her trust hinges on this. In addition to being Ladybug, she had a brief stint as Multimouse; after spreading rumors that she's been acting as a "talent scout" for her alter ego, she allows herself to be caught in the latter identity, then [[SayingTooMuch "accidentally" lets slip]] that somebody in their class has been {{stalk|erWithoutACrush}}ing Ladybug.
* In ''[[https://archiveofourown.org/works/37394824/chapters/93319366 La Lynxe et le Chatton]]'', Alix Kubdel is the user of the Black Cat Miraculous and [[AdaptationalGenderIdentity genderfluid]]. [[SupernaturallyValidatedTransPerson Since the Miraculous's outfit is based on the user's identity, Alix's outfit changes depending whether they are more feminine or masculine on a given day]]. As such, they go as La Lynxe Noire when female and Le Chatton Ombré when male, introducing both as separate individuals to their partner Coccinelle / Luka.
* ''Fanfic/ManagerSeraviel'': Taylor uses her power-managing abilities to create several alternate identities for herself.
** Her power-stealing identity, which uses an androgynous outfit made of a dress suit of Danny's and a veil, is dubbed Slenderman by PHO after a leaked video of her visiting and depowering Skidmark and Squealer hits the web. She later runs with that, using tinkertech and a careful selection of powers to play up the theme.
** Her first attempt at a crime-fighter persona, using tinkertech PowerArmor, gets abandoned before she even comes up with a name after Victor snipes her in the shoulder and drops a building on her.
** Apparition, an Undersider with shadow-movement powers. She uses a blonde wig and padding to separate this from her other personas, and later uses her cloning power to stage a fight between Appartition and Slenderman to further confuse the issue.
** Arsenal, a rogue tinker with PowerArmor and a deep male voice. She creates this persona both to have a crime-fighting option and to get access to better supplies through PRT affiliation.
* ''Fanfic/MarisStella'':
** When Sonya is Akumatized into Princess Nemo, she locks herself in a tower. Maris speculates that Princess Nemo will allow her crush Fletcher into the tower, so she asks Tenechat to lend Fletcher his Miraculous. [[DramaticIrony Unbeknownst to Maris]], Fletcher ''is'' Tenechat, leading to him creating a brand new identity, though admittedly less secret, in an effort to get Princess Nemo to allow him into the tower.
** The second time Sonya is Akumatized, instead of becoming Princess Nemo again, she becomes Bubblegum Witch.
** When Naota's brother Daichi is Akumatized and attempts to lock him up for his own protection, Naota uses time travel so he can be in two places at once, both as his normal identity Maris Stella and as the Goat Hero, Heiðrún.
** After the Ladybug Miraculous is stolen, Naota temporarily wields the Dog Miraculous and becomes Corgiranian.
** When they need to fight Quartz Chameleon in order to save Maris Stella and Tenechat, Erica, Sonya, and Arc are all given new super forms. Erica becomes Freesia Mage instead of Thorn Reaper, Sonya becomes Chaos Angel instead of either of her older forms, and Arc becomes Terrapin instead of Sharkbite.
** [[spoiler:After losing the Butterfly Miraculous, Yukari ends up borrowing the Ladybug Miraculous to become Akaribug when the new Butterfly villain akumatizes Lita.]]
* ''Fanfic/MiraculousCity'': Thanks to a freak event [[MassSuperEmpoweringEvent causing everyone in Paris to be able to use Miraculous powers]], this tends to happen to those who already had a Miraculous but now have indefinite access to their respective abilities.
** In chapter 2, when a group of expelled bullies invades and attack Dupont, Marinette uses her internal Ladybug powers to make a new appearance, which is publicly named "Maribug".
** In chapter 5, Sabrina (already the dog hero Miss Hound) transforms into Stray Hound when dragged by Chloe into performing heroics [[GlorySeeker for the latter's own desire for fame]].
** In chapter 6, when the same group of bullies turn villains attack a fair Adrien and Marinette are attending, he transforms into Cat Walker to help Maribug and Lady Beetle.
** In chapter 7, it's revealed by a flashback that Luka used an unnamed snake transformation [[ProperlyParanoid as a precaution]] when signing a record deal with [[CorruptCorporateExecutive Bob Roth]], which lets him turn back time after signing and learning how skewed the contract was in the fine print. In chapter 12, this new identity is named Snake Charmer while his sister Juleka has another Tiger form named Goth Tiger.
* ''Fanfic/AShadowOfTheTitans'': After ending up in the ''WesternAnimation/TeenTitans'' world, circumstances lead to [[WesternAnimation/JackieChanAdventures Jade]] (now [[ForcedTransformation changed into a Shadowkhan]] again) being mistaken for a villain and taken in by the HIVE; playing along, she takes the identity of a KungFuWizard called Zhu Chan. Later on, after her internship with the Joker goes south (as in, [[spoiler: he gives her a GlasgowGrin and she undergoes an EmergencyTransformation to survive]]), she goes into hiding in Gotham out of concern that the HIVE will [[YouHaveFailedMe terminate her for failure]]. To enable this, she changes into a new costume, complete with a plague doctor mask, and starts calling herself Karasu.
* ''Fanfic/SOE2LoneHeirOfKrypton'': Asuka created her ComicBook/PowerGirl identity when she became a superheroine for first time. Later she decided she had to become a different and better kind of heroine, so the she made a new costume and took a second secret identity as ComicBook/{{Supergirl}}.
* ''Fanfic/TaylorVarga'': Several of Taylor's cape allies create new super-identities for themselves as members or associates of the Family.
** Amy and Lisa use Varga-themed biosuits to disguise themselves as Ianthe and Metis, "cousins" to the Saurial/Raptaur/Kaiju branch of the Family. This also allows them to disguise Amy's biokinetic powers as a Family technique (especially since the biosuits allow Lisa to do some basic biokinetic tricks).
** Missy uses an old cloak and some new tricks for her SpaceMaster powers (learnt after exposure to the AlienGeometries that are a Family staple) to disguise herself as a cloak with nothing visible inside it but with powers similar to those of Vista, creatively named "Cloak".
** After defecting from the Merchants, Linda (formerly Squealer/Sherrel) takes advantage of having access to better materials to pretend to be an entirely unrelated Tinker with a similar specialty to Squealer. This is further supported by Amy giving her a basic Brute/Changer package.
** And then there is of course Taylor herself, who disguises the full scope of her shapeshifting by pretending to be multiple different reptilian capes with similar powersets.
* ''Fanfic/TheTickvsMyHeroAcademia'': Many of the students are active as both heroes-in-training and vigilantes, and thus have different names for each role.
** Midoriya has Jack Rabbit as his [[AdaptationalNameChange Official Hero name]] and Aphid as a vigilante.
** [[spoiler:Tsunotori has Rodeo as her Official Hero name and Tree Leaper as a vigilante.]]
** [[spoiler:Uraraka has Uravity as her Official Hero name and Dive Bomber as a vigilante.]]
** [[spoiler:Kaminari has Chargebolt as his Official Hero Name and Railgun as a vigilante.]]
** [[spoiler:Mineta has Grape Juice as his Official Hero Name and Dark Wine as a vigilante.]]
** [[spoiler:Ashido has Pinky as her Official Hero name and Alien Queen as a vigilante.]]
** [[spoiler:Kirishima has Red Riot as his Official Hero name and Black Diamond as a vigilante.]]
* ''Fanfic/WormWaterworks'': [[Literature/{{Worm}} Taylor]] starts to set up multiple Tinker Rogue identities.
** Plumber: specializes in plumbing, pipework, and liquid-based machinery.
** Sailor: specializes in aquatic vehicles and transportation.
** Hydroponics: specializes in irrigation, filtration, and water management systems.
[[/folder]]

[[folder:Films -- Animated]]
* In the 2007 ''WesternAnimation/{{TMNT}}'' film, Raphael becomes the vigilante known as Nightwatcher.
[[/folder]]

[[folder:Films -- Live-Action]]
* ''Franchise/MarvelCinematicUniverse'':
** Colonel James Rhodes takes on the superhero moniker of War Machine in ''Film/IronMan2'' when Tony Stark gives him an Iron Man suit. In ''Film/IronMan3'', in the face of terrorist attacks by the Mandarin, the US government decides to bolster public morale by rebranding Rhodey as the "Iron Patriot", complete with repainting his armor in a red-white-and-blue color scheme. Rhodey shows personal dislike for the name, and he quickly ditches the moniker after the movie, sticking solely to the War Machine moniker in all of his subsequent movie appearances.
--->'''Rhodey:''' It tested well with focus groups, alright?\\
'''Tony:''' "I am Iron Patriot!"\\
'''Rhodey:''' Listen, "War Machine" was a little too aggressive, all right? This sends a better message.
** [[WordOfGod A post on the Russos' Instagram]] confirmed that [[Film/CaptainAmericaCivilWar post-Civil-War]], Captain America ditched the shield and rebranded as the vigilante Nomad for ''Film/AvengersInfinityWar''. Black Widow, Falcon, and Scarlet Witch held onto their monikers but the entire group became known as the "Secret Avengers".
** ''Film/BlackPanther2018'' had Bucky Barnes aka the Winter Soldier use the nickname "White Wolf", a reference to a comic-book ally of the Black Panther.
** After his absence in ''Film/AvengersInfinityWar'', Hawkeye returned in ''Film/AvengersEndgame'' as "Ronin", with a new sword and haircut.
** ''Film/SpiderManFarFromHome'' features an ''unintentional'' one -- Spider-Man, while wearing Fury's stealth suit, is dubbed "[[AtrociousAlias Night Monkey]]" by [[BadLiar Ned]], who's trying to keep his girlfriend from realizing that it is in fact Spider-Man in order to preserve [[SecretKeeper his friend Peter's]] SecretIdentity. The press, hearing Ned and Betty call out to "Night Monkey" for help, refer to him by that name in their reports.
[[/folder]]

[[folder:Literature]]
* ''Literature/{{Brennus}}'': It's revealed that The Dark likes to do this in his spare time, by creating entirely new super-villain personas and using them to do mercenary work. Why? Because people tend to run away screaming when the world's greatest super-villain shows up, and he needs to keep his skills sharp through practice. It becomes useful when [[spoiler: his secret son need his help, and neither of them want people to find out about their relationship]].
* In a non-superhero example, Miss Level the witch from ''Literature/AHatFullOfSky'' used to perform in circuses as Topsy & Tipsy, a mind-reading act. This was made much easier because Miss Level's "superpower" isn't that she's psychic, but that she's one person with two bodies.
* ''Literature/{{Price}}'': Anima, as White Lady.
** The practice is so common in the setting that it's given a name: Moonnighting. A MultipleReferencePun on 'moonlighting' and the sheer number of heroes who use the word 'night' on the list.
* Both of the main protagonists of ''Literature/{{Renegades}}'' take up alternate identities to suit their needs, which forms a key part of the series. Nova, normally the villainous Nightmare, becomes the heroic Insomnia to spy on the Renegades, and has to rely on her FightsLikeANormal skills to compensate for supposedly only having a non-combat power. Adrian, normally the heroic Sketch, turns into the vigilante Sentinel to investigate his mother’s murder, and uses his art power and tattoos to give himself ComboPlatterPowers. Both of them use face-concealing masks in their non-Renegade identities to keep up the charade.
* In the ''Literature/WildCards'' series, the superhero Black Shadow killed a couple of criminals early in his career. Sought by the police, he simply adopts various other superheroic identities. He eventually starts thinking of himself as "Shad" just so he has an internal identity that he can cling to, because things have gotten so confusing.
[[/folder]]

[[folder:Live-Action TV]]
* ''Series/{{Arrowverse}}'':
** In Season 4 of ''Series/{{Arrow}}'' Oliver assumes his ''third'' identity. First he was known as "The Hood", then "The Arrow", and now the "ComicBook/GreenArrow". Each had his own costume and the public even thinks the Arrow is dead, not knowing that all these 3 were the same man. Eventually he does reveal himself as all three identities.
** In ''Series/CrisisOnInfiniteEarths2019'', Oliver briefly assumes a fourth and final identity: [[spoiler:ComicBook/TheSpectre]].
** Sara Lance went from being The Canary[=/=]ComicBook/BlackCanary to White Canary after joining [[Series/LegendsOfTomorrow the Legends]], although she's mostly [[ComicBookMoviesDontUseCodenames just called Sara]].
** ''Series/BlackLightning2018'': Aside from being the heroine Thunder, Anissa Pierce also sneaks around at night in dark hoods, brutally beating up criminals and stealing money for those in need. The streets label her second alias "The Blackbird". In season 3, she uses this alternate identity to join the resistance against the ASA, since the ASA is aware of her being Thunder.
* ''Series/{{The Boys|2019}}'': The superhero known as Stormfront [[spoiler:went by the name Liberty back in TheSeventies and operated out of North Carolina]], where she [[PoliticallyIncorrectVillain murdered black people for kicks]]. [[MegaCorp Vought International]] repackaged her and moved her around to avoid her violent racist outbursts being exposed, which Hughie likens to being the superhero version of a PedophilePriest being shuffled between parishes. After discovering her past, the Boys speculate that this has happened multiple times with her.
* ''Franchise/KamenRider'' has {{Transformation Trinket}}s pass hands quite a bit (at least in shows where they're purely mechanical devices with no mystical abilities), and characters will often assume another Rider's identity for one off-occasions like TheMovie.
** ''Series/KamenRiderRyuki'': In the AlternateUniverse movie ''13 Riders'', protagonist Shinji Kido loses the Ryuki powers and receives the Knight powers from a dying Ren Akiyama just in time to face off against all the other Riders.
** ''Series/KamenRiderDouble'' has probably the purest example of this trope, where the title character is normally a FusionDance between detective Shotaro Hidari and his brainy partner Philip. Starting with TheMovie, Shotaro has the "side identity" of Kamen Rider Joker, which he uses in situations where Philip isn't available; likewise, the spin-off novel has Philip becoming Kamen Rider Cyclone solo because Shotaro is laid up with a cold. These are mostly used in emergency situations, since Double is literally as powerful as both of them combined.
[[/folder]]

[[folder:Professional Wrestling]]
* From 1991, the true identity of wrestling NonIronicClown Command Bolshoi remained unrevealed. Haruyama #2, Miko-san, Piko, T-1 Mask, Medium, and [[JapaneseRanguage Dotonborishoi]] have been revealed to be the same person as Command Bolshoi however.
[[/folder]]

[[folder:Tabletop RPG]]
* ''TabletopGame/{{Champions}}'' supplement ''Champions III''. After a hero named Revenant killed a gang member and was indicted for 2nd degree murder, he continued operating as a hero under the name Kestrel.
* ''TabletopGame/{{GURPS}} Robin Hood'' included a ''TabletopGame/GURPSSupers'' version who maintained two identites. Known as a stolid and reliable energy-blaster for International Super Teams under the name Lightbolt, he's secretly also the killer vigilante Librum, dedicated to wiping out the city's drug dealers. He's managed to keep some aspects of his powers secret from IST, so they don't realise that Lightbolt's bright blue pulses of plasma and Librum's deep purple energy arrows are actually the same thing.
[[/folder]]

[[folder:Toys]]
* In the action figures based on the 80s TMNT cartoon, they released a Super Mike action figure who was basically a ComicBook/CaptainAmerica Expy persona that Michelangelo adopted. Super Mike also had a sidekick parrot named Crackers. They also made a Batman Expy identity for Don, known as Super Don. The Super Don action figure is based on the Dark Turtle Example below.
[[/folder]]

[[folder:Video Games]]
* In a meta sense every ''VideoGame/CityOfHeroes'' player is doing this once they create a second, third, forth... etc. character.
* In ''VideoGame/TheKingOfFighters XIV'', the King of Dinosaurs is actually Tizoc from ''[[VideoGame/FatalFury Garou: Mark of the Wolves]]'', who was previously a member of the ''KOF 2003'' and ''XI'' rosters; after getting beaten by Nelson he wanted a grudge match, but since that doesn't suit his {{Face}} persona he adopted a more villainous identity. Of course, [[CharlieBrownFromOuttaTown he's not very good at it]]: his character profile is still mostly identical to Tizoc's, he still goes on ForGreatJustice rants during his win quotes, and Terry Bogard sees through the disguise instantly and engages the [=KoD=] in a friendly conversation for a few moments before he realizes what he's saying and comically tries to reassume his shattered bad guy identity.
[[/folder]]

[[folder:Visual Novels]]
* In the WhereAreTheyNowEpilogue of ''VisualNovel/PhoenixWrightAceAttorneyDualDestinies'', masked wrestler The Amazing Nine-Tails, [[spoiler:Damian Tenma]], says he has recently started wrestling under a second, {{Heel}} persona in addition to his normal {{Face}} one. The problem is, the two personas have been scheduled to fight ''each other'' very soon, leaving him in quite the pickle.
[[/folder]]

[[folder:Web Animation]]
* ''WebAnimation/DrBees'' brings us Dr. Miles Manners. By day, he's an average wasp-themed superhero, but by night (despite his cartoons taking place in day), he becomes '''[[https://www.youtube.com/watch?v=PYtXuBN1Hvc DR. BEES!]]'''
[[/folder]]

[[folder:Web Comics]]
* In ''Webcomic/SwordCatPrincess'', when the NYPD created a task force to capture Artemis, [[http://swordcatprincess.thecomicseries.com/comics/136/ she continued to fight crime as SwordCat Princess.]]
[[/folder]]

[[folder:Web Original]]
* In ''Webcomic/DocRat'', [[http://www.docrat.com.au/default.asp?thisItem=841 Captain Kerpow's secret identity is Awesome Possum, another crimefigher.]]
[[/folder]]

[[folder:Western Animation]]
* In one episode of ''[[WesternAnimation/BatmanTheAnimatedSeries The New Batman Adventures]]'', Batman faces a new vigilante in town who calls himself "The Judge", who is going after the city's criminal element and has a more violent manner of dealing with them. Batman tries to stop him as he targets ComicBook/TwoFace, [[spoiler:only to discover at the end that The Judge is really a new multiple personality of [[ComicBook/TwoFace Harvey Dent]].]]
* ''WesternAnimation/TheFairlyOddParents'' episode "Gone Flushin'" has Catman become Ratman due to winding up in the sewers after an orderly at the nursing home flushed him down the toilet under the belief that he was dead when he was only napping. He got the rat costume because Timmy's Dad flushed it down the toilet due to the costume being dead to him.
* ''WesternAnimation/MiraculousLadybug'':
** A villainous example is present in the episode "[[Recap/MiraculousLadybugS02E01TheCollector The Collector]]", [[spoiler:where [[Characters/MiraculousLadybugHawkMoth Gabriel Agreste]], revealed to be Hawk Moth, akumatizes ''himself'' and turns into The Collector to throw off any suspicion that he is the BigBad]].
** This also goes for some of the other villains -- some characters who have been akumatized before get turned into new villains. For example, Lila has been Volpina before and later becomes Chameleon, Kagami has been Riposte before and later becomes Oni-chan and Lies, Sabrina has been Vanisher before and later becomes Miraculer, and Luka has been Silencer before and later becomes Truth.
** A heroic example almost happens in "[[Recap/MiraculousLadybugS02E20StyleQueenQueensBattlePart1 Style Queen]]" when Ladybug goes to give [[Characters/MiraculousLadybugAlyaCesaire Alya Césaire]] the Bee Miraculous. Alya had previously wielded the Fox Miraculous as Rena Rouge. Subverted when Alya is struck by Style Queen and becomes a statue. The Miraculous then falls into Chloé's hands...
*** Alya would be able to play the trope straight in the season four episode "Hack-San" [[spoiler:when Marinette entrusts her to be the temporary Ladybug Scarabella while the former is out of Paris]].
** Put the above examples together, and you get Queen Wasp. Chloé has already been akumatized into being Antibug, but when she's akumatized while using the Bee Miraculous, she goes from Queen Bee to Queen Wasp.
*** And in the Season 3 finale, [[spoiler:she gets a third villainous identity as "Miracle Queen", once again akumatized while as Queen Bee.]]
*** And then in season 4 [[spoiler: she once again gets akumatized into "Queen Banana".]]
** Similarly to Queen Wasp, in the Season 2 finale, Alya and Nino are akumatized while using the Fox and Turtle Miraculouses, respectively, and are turned into EvilKnockoff versions of their superhero selves rather than their former villainous selves, Lady Wifi and Bubbler.
** Chloé's half-sister Zoé Lee, who is [[spoiler:the second Bee Hero Vesperia]] would get a second hero form in the season 5 two-part special "The Kwamis' Choice" [[spoiler:when she becomes the temporary Cat Hero Kitty Noire]].
** [[Characters/MiraculousLadybugMarinetteDupainCheng Ladybug]] and [[Characters/MiraculousLadybugAdrienAgreste Cat Noir]] themselves get a few of these.
*** In the episode "Reflekdoll", they swapped Miraculouses, becoming Lady Noir and Mister Bug.
*** In "Desperada", Ladybug entrusts Adrien with the Snake Miraculous, becoming Aspik. [[RefusalOfTheCall Adrien eventually turns this down,]] believing he's not the one for the job and that Cat Noir is necessary to take down the titular villain, having [[GroundhogDayLoop tried and failed]] [[{{Determinator}} over 25,000 times]].
*** In "Kwamibuster", Marinette uses the Mouse Miraculous to become [[SelfDuplication Multimouse]], and some of her alternate selves use another Miraculous on top of that. She later allows Cat Noir to see that they're the same person (using a Mirage to make it look like Ladybug and Multimouse/Marinette are present at the same time), simply to throw him off the scent of her normal secret identity.
*** In "Kuro Neko", [[spoiler:Adrien uses an alternate transformation with the Cat Miraculous to become Cat Walker]].
%%*** Marinette also combines the Dragon Miraculous with the Ladybug one. At some point, Adrien combines his Cat and Snake Miraculouses.
* ''WesternAnimation/TheSpectacularSpiderMan'' has a villainous example: Season 2 introduces a mysterious villain called the Master Planner, who turns out to be [[spoiler:Doctor Octopus, who had pretended to be reformed.]]
* In ''WesternAnimation/TeenTitans2003'' Robin becomes "Red X" for an episode. Later the costume is stolen and [[TheRealRemingtonSteele a new Red X shows up]], [[RiddleForTheAges whose true identity remains unknown]].
* ''Franchise/TeenageMutantNinjaTurtles'':
** In the ''WesternAnimation/TeenageMutantNinjaTurtles1987'' cartoon, Donatello becomes the superhero known as Dark Turtle when [[IdentityAmnesia he hits his head]].
** And in ''WesternAnimation/TeenageMutantNinjaTurtles2003'', Michaelangelo becomes the "Turtle Titan," especially when hanging out with Justice Force.
[[/folder]]
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