Rogues Gallery Transplant

Also known as The Supervillain Shuffle. The occurrence wherein a villain, originally introduced as an enemy for a specific hero, subtly through time or Continuity Creep, deliberately or unintentionally, becomes more identified with another hero.

While any Shared Universe may depict a hero fighting another's antagonist, usually they remain identified with the original. For instance, Superman may occasionally fight The Joker, but no one would claim the latter is anything but a Batman villain. This trope refers specifically to characters that have reached the narrative point where the villain is now more identified in the popular consciousness as being an adversary to a character he did not originally fight.

Often occurs when an obscure character is used in a recent popular work or adaptation. In many cases, it also happens when the villain is better suited to another hero either thematically or with regard to powers, especially if the themes or powers of the hero have changed in the interim. Can also be the result of a writer creating a villain while writing for one character, then moving on to another project and taking all of their toys with them.

Comic Books

 * Wilson Fisk, the Kingpin, was introduced as a Spider-Man villain, and though Spidey still fights him on occasion, you'd be hard-pressed to say that the character is not best known for being a nemesis of Daredevil, taking the place of the Owl (who is a lot harder to take seriously) among his enemies.
 * Referenced (but not used directly) in Spider-Man: The Animated Series; Fisk is the Big Bad for much of the show, but in the episode where Daredevil does appear, it's made very clear that for him, It's Personal, while for Spidey, it's more of your standard hero/villain thing.
 * Other Spidey villains have been known to torment Daredevil from time to time, and vice-versa; the guys practically live next door to each other, so there's a ton of overlap. Inverted with Mysterio who seems to have not so much transferred to Daredevil's gallery as branched out, becoming an enemy of both of them.
 * By comparison, the various Green Goblins were notable for being solely Spider-Man villains, never antagonizing other New York-based heroes as Doctor Octopus or Electro would. Since Secret Invasion, however, Norman Osborn has been transformed into an over-riding Big Bad of the Marvel Universe. He has been able to stay at that level even after Dark Reign.
 * Fin Fang Foom was originally a general Marvel Universe monster. He has become an Iron Man villain to the point that he has appeared in both Iron Man cartoon series, was featured in the animated movie, and was considered as a foe for the live-action Iron Man movie... presumably without the purple shorts.
 * Solomon Grundy was originally specifically an enemy of the (Golden Age) Green Lantern. However, since the Green Lantern titles now tend to focus on more interstellar action, Solomon now fits more into Batman's Rogues Gallery.
 * The Shade was originally created as a villain for The Flash, but in the modern age, he's perhaps best known for being a Trickster Mentor for the Jack Knight incarnation of Starman.
 * An in-universe version is how the Mist originally fought the Wesley Dodds incarnation of the Sandman before moving to Opal City and fighting Starman. This fact is used as a plot-point in the 1990s series.
 * Doctor Destiny was originally created as a villain for the Justice League of America, and specifically Green Lantern. However, he is now almost certainly best known today for being the sap who got his hand on the magical ruby created by the King of Dreams, Morpheus, in The Sandman.
 * Jason Woodrue the Floronic Man, created as an adversary of The Atom, is obscure outside of his appearances in Alan Moore's run on Swamp Thing and Neil Gaiman making him integral to the creation of Poison Ivy in a Secret Origins story.
 * The Cyborg Superman was, unsurprisingly, originally created as a recurring villain in the Superman titles. The character then disappeared for several years. The Cyborg has since re-emerged as a Green Lantern villain, with many of his Superman-related appearances excised from continuity, due to his actions in Reign of the Supermen touching off Hal Jordan's temporary Face Heel Turn.
 * The same thing happened with Mongul Jr. His father was a Superman villain, and also the one who helped the Cyborg-Superman destroy Coast City. After being killed for refusing a pact with, and then trying to punch, Neron, his son appeared a few years later as a foe of Superman. Nowadays, he fights Green Lantern and the Green Lantern Corps.
 * Mephisto works well as a recent, deliberate example: He was originally introduced in the Silver Surfer series, but has spent stints as an adversary of both The Mighty Thor and Ghost Rider. To the modern reader, though, he's best known for his role in One More Day.
 * Mephisto is best understood as a member of the Rogues Gallery for the wider Marvel Universe, rather than any one hero, which is fitting as he is basically a stand-in for Satan. He has tangled with near enough every single major hero and several villains, and is a lot more personal for many.
 * Clock King was originally introduced as an adversary of Green Arrow, but is now considered to be a minor member of Batman's Rogues Gallery, due in large part to his appearances in The DCAU. (And the sixties TV series.)
 * Darkseid is a circular example of the trope. He was introduced in Superman's Jimmy Olsen title, en route to becoming the specific villain of the New Gods series. With said title's cancellation, he has become associated as part of the Superman rogues gallery. This likely due to how well he serves as a counterpoint to the Man of Steel: a super-powerful alien who comes to Earth to rule mankind, not serve it, and being one of the few foes of a similar weight class.
 * He's also fairly strongly associated with the Legion of Super-Heroes, thanks to the classic storyline "The Great Darkness Saga".
 * He's also become a popular villain for Crisis Crossover stories that encompass all of The DCU, such as Legends in 1986, Genesis in 1997, and Final Crisis in 2008.
 * Rhino was introduced as a Spider-Man foe but has spent most of his career battling The Hulk. At the very least, it's shared custody.
 * Professor Arnold Hugo (a man who gave himself super-intelligence at the cost of an oversized cranium), debuted as a Batman opponent, but languished in obscurity until he was reused as a Martian Manhunter foe, reappearing several times.
 * Thanos first appeared as an enemy of Iron Man, though he is now more commonly linked with the Silver Surfer mythos, (Marvel Comics') Captain Marvel, and then with Adam Warlock.
 * Like Mephisto, he's now pretty much a general enemy of the entire Marvel U.
 * Seems to be all over Wolverine's mythos. He started out as a foe of the Hulk, and Sabertooth was a foe of Iron Fist.
 * Sabertooth had originally been intended to be Wolverine's father by creator John Byrne (he was based on Byrne's rejected design for Wolverine sans mask), but ended up getting dumped on the second-string titles when Claremont and Cockrum weren't interested.
 * Also notable is that Lady Deathstrike first appeared fighting Daredevil.
 * A lesser example would be Omega Red who started off as an X-Men foe before focusing squarely on Wolverine.
 * Superman's first supervillain was the Ultra-Humanite, but he was retconned to be a Justice Society of America villain after Golden Age Superman was removed from continuity.
 * He also served as the main villain of Power Girl's solo series.
 * Sandman was introduced in the pages of The Amazing Spider-Man and has a regular baddie for some time before switching over to menace the Fantastic Four for some time with the Frightful Four then go solo again fighting Spidey.
 * The contract killer Boomerang, who uses deadly gimmick boomerangs as his weapons, originally started out fighting the Hulk, before he moved on to become a semi-regular Spider-Man villain after writers realized that trick boomerangs versus the most powerful creature on earth was a bit of a mismatch.
 * Mister Hyde, a villain based on the story of the same name, started out as a Thor villain but would later move on to become a Daredevil regular, although he also took the time to mess with Spider-Man, Captain America, Ghost Rider, and the Hulk, finally settling in to become a regular foe of Cap, DD and the Big Green Machine.
 * Cobra, Mister Hyde's sometime partner, also started out as a Thor villain. Wisely, he has decided against challenging the god of thunder and became a foe of Daredevil and Captain America. You think Cobra and Hyde had a sit down over beers and agreed to only fight guys they had a chance of defeating?
 * If he wanted to face someone he had a chance of defeating, Hyde wouldn't pick a fight with Hulk.
 * Although to be fair, an early storyline had Loki enhancing both their powers so they stood a chance against Thor. This troper doesn't recall if that ever wore off/retconned or not.
 * In the very early days of the Marvel Universe, the original Human Torch had his own rogues gallery as a solo hero. Two of his mainstays, the Wizard and the Trapster, would later become enemies of the Fantastic Four, with the Wizard becoming an Evil Counterpart to Reed Richards and even forming his own Evil Counterpart team in the Frightful Four, of which the Trapster was a charter member. The Trapster and the Beetle, another long-standing enemy of the Torch, would also become recurring enemies of Spider-Man. The Eel also originally debuted as a foe of the Human Torch before becoming a semi-regular Daredevil villain.
 * Many of the enemies the various members of The Avengers had faced as solo heroes would later become enemies of the team as a whole, with characters like Egghead, an enemy of Ant-Man, AKA Henry Pym, Baron Zemo (an enemy of Captain America), the Norse trickster god Loki, an enemy of The Mighty Thor, the Mandarin, the Arch Enemy of Iron Man all becoming some of the Avengers' worst enemies.
 * This would also get inverted. The first incarnation of the Masters of Evil featured the Black Knight as a foil for Wasp and Giant Man and Radioactive Man as the foil for Thor. Soon after, both became regular enemies of Iron Man.
 * The Silver Samurai and Arcade debuted in the pages of Daredevil and Spider-Man, respectively, but these days they're better known as X-Men villains.
 * Mystique first appeared in Ms. Marvel and was originally slated to be her Arch Enemy. She's pretty much entirely an X-Villain nowadays, and her history with Ms. Marvel (such as killing her boyfriend) has been all but forgotten.
 * She did return to torment Ms. Marvel in Carol's recent series.
 * Deathstroke the Terminator started out as a Teen Titans rogue, turned towards antiheroism, and then became (after Identity Crisis) a sort of generic DCUniverse villain, being as much of a dick to as many superheroes as he could manage.
 * He seems to have a hobby of harassing young heroes. He's never let go of his grudge against the Titans since he never completed his contract against them (a bit of a blow to his merc cred). He even went so far as to harass Damian Wayne, his Arch Enemy Nightwing's (now Batman) protege.
 * Superboy-Prime first appeared as a hero in the Superman team-up series DC Comics Presents. His Face Heel Turn occurred in a Crisis Crossover called Infinite Crisis, which put him up against many heroes of The DCU. He later faced Green Lantern as an ally of the Sinestro Corps. After that, he fought The Legion Of Super-Heroes during Final Crisis. Most recently, he got to be the Villain Protagonist of his own Evil Versus Evil story during Blackest Night.
 * Apocalypse first appeared in X Factor as the leader of the Alliance of Evil (a role, again, originally intended for the Owl) eventually becoming their Big Bad, getting killed, and, upon resurrection, graduating to become one of the X-Men's most powerful foes and being Ret Conned as Cable's archenemy.
 * Deathbird started as a Ms. Marvel villain before becoming a recurring foe of the X-Men in general and Professor X's girlfriend Lilandra (her sister, as it turns out) in particular. Like Msytique above, this is a result of Chris Claremont creating a villain for one book, then moving her to another when the first was canceled.
 * The demon Blackheart debuted in Daredevil, though now spends most of his time messing with Ghost Rider, even appearing as the villain in the movie adaptation. He also shows up in the X-Men from time to time (amongst others), even at one point serving as the Black King of the Hellfire Club.
 * Minor-league Iron Man villains Blizzard and Firebrand started out fighting Shellhead, but eventually transitioned to fighting street-level heroes like Spider-Man after Tony Stark's equipment began to completely outclass theirs.
 * Moses Magnum started out fighting Spider-Man and The Punisher, but seems to have eventually settled on antagonizing Black Panther. Thematically, Magnum and T'Challa are a perfect fit.
 * Bolivar Trask is most associated with the X-Men in mainstream Marvel continuity, but in the Ultimate Universe he became integrated into Ultimate Spider-Man's mythos, eventually becoming the Big Bad of the video game adaptation.
 * The Absorbing Man, who was able to mimic and absorb the physical properties of anything he touched, started out as a recurring enemy of The Mighty Thor and remains a charter member of Thor's Rogues Gallery. However, he's also tangled with the Incredible Hulk enough times that, as with the Rhino (see above), it's arguably shared custody.
 * Doctor Doom was created to be the main nemesis of the Fantastic Four. While he still maintains that role to the present day, he has since become one of the overall Big Bads of the Marvel universe and has fought pretty much every single Marvel hero.
 * In Archie's Sonic The Hedgehog series, the Dark Legion - a group of villainous Echidnas - was originally created to serve as enemies of Knuckles, acting as the central antagonists of his spin-off. However, after the "Enerjak Reborn" arc in the main series (several years after the Knuckles spin-off was cancelled), the Legion allied with Sonic's Arch Enemy Dr. Eggman and began serving as his personal army. Therefore, they can be seen as much Sonic's enemies as Knuckles' these days.
 * MODOK was originally created as a foe for Captain America. However, in his role as leader of AIM, he's been increasingly an antagonist of Iron Man.
 * The Electrocutioner began as a one-shot Batman villain before appearing in The Vigilante where he became the closest thing Vig had to an archenemy. Since the Vigilante's death, he has returned as a sporadic Batman foe.
 * Annihilation has the Fantastic Four's long-time foe Annihilus launching a devastating attack on the universe, uniting cosmic heroes like Nova and the Silver Surfer against him. Even through Annihilus returned a few years later to fight the first family again, he is now generally considered a threat to the entire universe.
 * Annihilation Conquest does a similiar thing - Avengers villain Ultron takes control over the Phalanx, a race mostly known for their fights with the X-Men, as well as few lesser-known villains like the Avengers' enemy Ultra-Adaptoid or the Fantastic Four's foe Blastaar, and then goes against cosmic heroes. Ultron later returned to fighting the Avengers, though.
 * In a similar vein, War of Kings is driven by conflict between the Kree Empire, ruled by the Inhumans, and the Shi'Ar Empire, ruled by X-Men foe Vulcan. Time will show to antagonizing which group will Vulcan stick.
 * The Thanos Imperative and a few other apperances helped classic Doctor Strange enemy Shuma-Gorath get upgraded to universal threat, like Mephisto or Thanos.
 * Demogorge the God Eater and Amatsu Mikaboshi all debuted as the antagonists of The Mighty Thor. To modern reader they are probably know as enemies and occasional allies of The Incredible Hercules.
 * The Queen of Fables started out attacking the entire JLA, but now she is an enemy to both Wonder Woman and Superman.
 * The Punisher has few reoccuring villains due to his deadly nature but one of his few villains, Jigsaw, started off as a Spider-Man villain, although his introductary story did involve Punisher as well.

Film

 * The Kaiju Baragon was originally the enemy of a giant version of Frankenstein's Monster. However, Baragon eventually became part of Godzilla's Rogues Gallery thanks to video-games, action figures, and the films Destroy All Monsters and GMK.
 * While Maleficent is still primarily known as the main antagonist of Sleeping Beauty, crossover shows and theme park attractions, as well as Kingdom Hearts, usually make her something like an arch-Disney villain and her connections to Princess Aurora are barely mentioned.
 * Both Alien and Predator started as antagonists in their own movies. Today, thanks to humongous franchiche of movies, games, comics and novels, two races are more known for fighting each other.

Live Action TV

 * Darla was introduced in Buffy the Vampire Slayer as a Dark Action Girl Female Vampire Antagonist for Buffy, though was killed off soon after her debut. However, she was revived as a much more potent and ongoing adversary for Angel in his eponymous spinoff; even in Buffy they had a much more significant connection, as Darla was established as both his vampiric sire and former lover.
 * The Slitheen family started out as briefly recurring antagonists (two episodes, one of which was a two-parter) of the Ninth Doctor, then disappeared from the main series and started showing up frequently on The Sarah Jane Adventures.
 * The Cardassians began as villains of the week on Star Trek: The Next Generation but ended-up with much greater plot significance on Deep Space Nine.
 * To a somewhat lesser extent, the same thing could also be said of the Romulans being more associated with The Next Generation than with TOS.
 * The Borg are partially this trope and partially an aversion. They had only four TNG episodes (of which two were two-parters) plus First Contact. Compare this to their twenty (of which two were two-parters) appearances on Voyager, plus a Borg character joining Voyager's main cast for the last four seasons. (They also appeared in one episode of Enterprise, and formed a major part of Sisko's backstory on Deep Space Nine.) Despite this, in popular consciousness, the Borg are still considered Picard's nemesis.

Video Games

 * While the Super Robot Wars series does, of necessity, involve various Humongous Mecha fighting enemies from different shows, it can sometimes veer into this territory with especially strong enmities developing between characters of different series, especially in regards to Original Generation characters. The best example would probably be from Super Robot Wars Original Generation 2, where Axel Almer of Super Robot Wars Advance fame becomes the arch nemesis of the Pact series' Kyosuke Nanbu.

Web Original

 * The Angry German Kid originally started out as a Youtube Meme, but eventually became one of the main memes at Nico Douga, with the new moniker of Keyboard Crusher.
 * In the Global Guardians PBEM Universe, Doctor XX was originally created to be an ongoing antagonist for the titular Global Guardians team. But then, after the Game Master for the Hyperion Academy campaign got ahold of her, she tended to never appear in any other campaign so as to "not ruin her amazing portrayal in that campaign".
 * In a reverse of the previous example, The Blood Red King was originally intended to be a semi-demonic villain for the Knights of Malta (a team of superhero priests, monks, and nuns sponsored by the Roman Catholic Church). He ended up fighting the Global Guardians more than any other hero team in the setting.

Western Animation

 * Most of the villains on Batman the Brave And The Bold qualify, Gentleman Ghost in particular. He was a minor enemy of Hawkman, but has had three episodes in a Batman-centric show devoted to him and Hawkman hasn't even been mentioned yet. His latest appearance actually has Batman replacing Hawkman in the Ghost's origin story, which more or less explains the difference.
 * The series seems to be trying to do this on purpose. Outside of his own (rarely used) rogues' gallery, it's actually fairly rare for Batman to fight an enemy that regularly opposed the team up partner for that episode.
 * Big Bad Pete originally appeared in Walt Disney's Alice Comedies before becoming an enemy of Oswald the Lucky Rabbit and eventually Mickey Mouse. In the later years of Disney shorts, Pete mainly menaced Donald, though mainly as a bullying jerkass than a straight up villain. To modern audiences he's probably best known for his role as Goofy's Poisonous Friend on Goof Troop, or his role in the Kingdom Hearts series.
 * And speaking of Disney comic book villains: Emil Eagle originally was made up to give Gyro Gearloose a criminal rival, but he later became a recurring character in Mickey Mouse comics by Paul Murry et al., mostly to explain how people like Idget the Midget and Dangerous Dan McBoo or Pete could have sophisticated plans or super-science equipment.