Rokk: Kal-El, I have to tell you - we've heard of Lois Lane, Lana Lang, even Jimmy Olsen, but we've never heard a thing about any "Chloe Sullivan". Clark: ...Then you don't know me as well as you think.
When an established existing medium ventures into the Expanded Universe, writers will often rely heavily on familiar characters and past storylines from the official canon to ensure that fans of the original material are happy. Unlike the original canon, however, an "expanded universe" adaptation also gives the writers freedom to introduce new, "never before seen" characters, as the production staff enjoys their newfound liberation from whatever codes and limitations ruled the original work.
Often, these new characters will be added to fill a particular need in the new story, and add some degree of novelty to attract readers/watchers. Frequently, they'll also fill some gap in the current cast, such as adding a female character to an all-male cast, or imposing some other element of diversity, be it racial, geographic, or simply personality. This can spark new conflicts and adventures that wouldn't otherwise occur under the limitations of the "conventional" cast and series format — one of the main points of "expanded universe" fiction to begin with.
Depending on how well the character fits into the adaptation or how much the fans like the character, Canon Foreigners can either be much beloved or much hated, and if popular enough, may be Ret Canoned into the official canon where they are known as Canon Immigrants.
Filler Villain is a Sub-Trope of this.
Compare Original Generation characters, who are Canon Foreigners to several canons at once in a Crossover plot.
See God-Created Canon Foreigner when this character comes from the original creator.
Ashil from the Shaman King anime. And the Lily Five, who became surprisingly popular among the fans.
The Aliens and the Makaiju in the first arc of Sailor Moon R, the similarly themed Fiore in the Sailor Moon R movie and Perle & the villains from the Sailor Moon SuperS movie. Also Yūichirō, Rei's love interest.
Kiyone from Tenchi Muyo! was added in the TV version as a Straight Man foil for Mihoshi. She has since become one of the more popular cast members, but never featured in the original OVA canon, where her name is used for a completely different character.
She has a counterpart in the third OVA in Noike; the green-haired, no-nonsense former partner of Mihoshi.
She is also in the semi canonical Mihoshi Special (Which in canon is Mihoshi telling a story which may or may not be based on real events) and the movie Daughter of Darkness which takes place in the OVA continuity.
Sasuke Sarugakure, the ninja servant of the Kunō family in the Ranma ˝ anime, is at least a semi-regular character who never appears in the original manga. On his first appearance, he did the actions originally done by Gosunkugi, a character oddly removed from the anime at first, and introduced much later. There are a number of other anime-only characters, but few of them appear in more than one episode.
The Fatal Fury anime movies had Lily McGuire, Tony and his mother Elsa in the TV specials, as well the Gaudeamus siblings Sulia and Laocorn, Panni, Hauer and Jamin in The Motion Picture.
Lily does make a cameo in the Mexico stage of The King of Fighters '94 (alongside other SNK characters), and, as they were love interests and Lost Lenores to Terry in their respective appearances, both Lily and Sulia are mentioned by him in Days of Memories, an AU Dating Sim series featuring several SNK IPs.
Homura, the Big Bad of the second season of Gensoumaden Saiyuki, and his two henchmen, Zenon and Shien. Homura didn't make it to Canon Immigrant status, but original manga-ka Minekura Kazuya did write and illustrate an Omake chapter about him.
Sonic X featured more Canon Foreigners than characters from the games. Most notably are the Thorndyke family, Eggman's crew, Cosmo and Dark Oak.
Street Fighter Alpha: The Animation has Dr. Saddler, Rosanov, Wallace, and Shun (Ryu's "brother"). The manga adaptation of Street Fighter II by Masaomi Kanzaki also has a girl named Po-lin and her brother Won-mei, who befriend Ryu. The Street Fighter Generations OAV gives us the unnamed Old Master, his granddaughter Fuuka and a woman from Akuma and Gouken's past named Sayaka.
Many of the star trainers from Pokémon Special are taken directly from the main game series (Blue herself existed as a Mythology Gag), yet Yellow and Emerald are the only ones with no canon video game equivalents.
The anime adaptation of Slayers has quite a few of these, with the standouts being Zangulus from the first season, Martina from the second, Filia, Valgaav, his henchmen, and the guardians of the Black Orb from the third, and Pokota from the fourth and fifth.
The manga adaptations that branched off even further from the novel canon also has these, namely Lyos from Knight of the Aqualord and Noah and Ranzam from Hourglass of Falces. There's also the video games, with Lark and Rynnea from the Royal games and Demia and Viola from Slayers Wonderful.
Yu-Gi-Oh! has many, but one of the most notable would be Noah Kaiba; the character would be the actual son of Gozaburo Kaiba (Mokuba and Seto's foster father), who conveniently died right before Mokuba and Seto arrived at the Kaiba manor. He also looks a lot like Seto, even though they're not blood-related.
InuYasha has a few. Ayame, a wolf-demon girl and supposed bride-to-be to Koga; Akitoki Hojo, a past ancestor of one of Kagome's classmates. Kagome's friends, Eri, Ayumi, and Yuka, could also be considered as such. While they appear in the manga only one of them (Eri) is named and they hardly have any parts to play as opposed to the anime where they're used for many a filler.
Code Geass has several due to its various spinoff manga and video games, including literal Evil Twins Castor and Pollux from the Nintendo DS game; Rai, the protagonist of the Visual NovelLost Colors; Mariel, Suzaku's Love Interest in Suzaku of the Counterattack; Nunnally's best friend Alice and the other Irregulars from Nightmare of Nunnally, and more.
The Gurren Lagann manga introduces Nia's eldest sister, Princess Straea, who was discarded many years ago only to have chosen to serve her father by running the all-women village for him, and now wants Nia to take her place.
Traditionally there are four Saint Beasts as was the case in Angel Tales with Goh, Shin, Rey and Gai filling these roles. When Angel Tales spawned a rather different spinoff, Saint Beast, Judas and Luca were created to be the main characters and the Saint Beasts became six instead. Also, instead of the goddess, Zeus became the head god of heaven.
Marvel Anime: X-Men had Yui Sasaki and her son Takeo, who essentially acted as Japanese versions of Moira MacTaggert and Legion. There were also a few minor characters like the U-Men member Kick and Armor's best friend Kyoko.
Trigun: Several one-shot villains in the first half of the anime, a few of which even wound up making cameos in the manga, most notably Descartes. Gung-Ho Guns Caine the Longshot and Chapel the Evergreen are exclusive to the anime (although Chapel does have an equivalent in the manga).
The numerous anime that drew from Mahou Sensei Negima! surprisingly do not add a lot for all of the changes they make; the most well-known immigrant was the demonic king that made a Deal with the Devil with Asuna, which ends up in her death from the 2005 anime adaptation.
Puella Magi Oriko Magica uses this heavily, with Oriko, Kirika, and Yuma, the inhabitants of a mystery timeline where where the titular character decided to muck with the events of the series. The question of what happened in the other timelines would eventually be answered in a spinoff starring only Canon Immigrants.
The Captain Tsubasa original series gives us Rika Oosawa, a half-Japanese/half-French Plucky Girl who befriends Tsubasa and the Japanese Team and acts as their tour guide when they go to France. She also appears in the non-canon movies.
The Big Finish Doctor Whoaudio plays had Erimem (companion to the Fifth Doctor), Evelyn Smythe (companion to the Sixth Doctor), Hex and Raine Creevey (both companions to the Seventh Doctor), Charley Pollard (Eighth and later, at least from her point of view, Sixth Doctor companion), C'rizz, Samson and Gemma Griffen, Lucie Miller, and Mary Shelley (all companions to the Eighth Doctor) all slotting in around gaps in the timeline of the TV series.
While Archie Comics' Teenage Mutant Ninja Turtles Adventures was originally meant to be a Recursive Adaptation of the original cartoon, it eventually featured a good dozen original characters. The most prominent were allies Ninjara, Oyuki Mamishi, Ray Fillet, Jagwar, Dreadmon, and Cudley the Cowlick; and villains Armaggon, Verminator X, Null, and Maligna.
And while we're on an Archie kick: in Archie Comics' Sonic the Hedgehog, canon foreigners outnumber characters adapted from the games or the Saturday Morning cartoon.
Sonic the Comic (alternately known as Fleetway Sonic) also contained many canon foreigners, supposedly based on the various critters released from Badniks in the first Sonic game, such as Johnny Lightfoot (a rabbit) and Porker Lewis (a pig). It also included squirrel turned invincible Badnik "Shortfuse the Cybernik", and a whole legion of Mecha-Mooks known as "Troopers".
The rarely seen Sonic manga released by Shogakukan in 1992 also had some canon foreigners of it's own. Aside from the three main characters of the games at that time, it also featured Nikki as an ordinary version of Sonic, Nikki's family (Anita, Brenda and Paulie), Little John, Anton, Madd, Amy and Charmy.
Campion Bond of The League of Extraordinary Gentlemen. When every other character, no matter how background or minor, is taken from a work of Victorian literature, it is a shock to find a main character that's completely original, although an ancestor of James Bond). Other Canon Foreigners are ancestors of other fictional characters, like the ancestor of The Dude who makes a brief appearance in The New Traveler's Almanac. More prominently, William Sampson, the League's cabbie, is the father of the Wolf of Kabul, from The Hotspur.
Originally the creators of The X-Files comics were told they could not use the character of the Cigarette Smoking Man so they created a mysterious blonde woman to fill his role. Later the producers changed their minds and the comics were allowed to use CSM and the mysterious blonde quietly vanished. It is unlikely she will ever appear in any other X-Files adaptation.
The comic books made to tie-in to Justice League had a few as well, the most notable probably being the teen superheroine All-Star.
The Star Trek comics produced by DC in The Eighties featured a plethora of original characters, until Paramount exerted greater creative control over the series. This resulted in the cancellation of the first volume after issue 56, a new series launching after the debut of Star Trek V: The Final Frontier, and the characters created by Mike W. Barr and his successors on the first series (including the final writer of the first series, Peter David), as well as the Star Trek: The Animated Series characters, to be banned from use in the new series.
Peter David attempted to add his own original characters, such as protocol officer R.J. Blaise, security officer Fouton, navigator Kathy Li, and a recurring villain, the Salla. Paramount (and Richard Arnold in particular) wasn't happy with anything taking focus away from the original cast, even though these characters existed primarily to play off of that cast (Blaise and the Salla for Kirk, Fouton for Chekov, and Li for Sulu), and Arnold ordered these characters removed by the end of the "Trial of James T. Kirk" arc. David, frustrated over his scripts getting rejected by Arnold, submitted a particularly violent story under the pen name Robert Bruce Banner, which was accepted. Concluding that his issues with Arnold had become personal, David quit the series following the "Return of the Worthy" arc, on which he collaborated with Bill Mumy; the "Banner" story would get published (under David's name) a few issues later. David did get to write a few more DC Star Trek issues (notably, the TNG portion of The Modala Imperative, and a Star Trek Special that allowed him to give R.J. Blaise a proper send-off).
As with Star Trek, the Star Wars comics added dozens if not hundreds of new characters. Two of them — Aayla Secura and Quinlan Voss (mentioned but not shown) — actually make it Canon Immigrant status.
In the late 1980s, DC Comics did a Doc Savage series that centres around Doc being moved through time to the present day. The series included Doc's grandson and a team of new aides Doc assembled (as his original aides were now all old men). While interesting, these characters are unlikely to appear in any other version of the Doc Savage saga.
In an odd bit of a Recursive Adaptation, the official tie-in comic for the Young Justice animated series added three more members to the Flying Graysons, the family of acrobats Dick Grayson belonged to before becoming Robin. While the Flying Grayson troupe from the comics consisted of Dick and his parents, the Young Justice comic introduced Richard, Karla and John Grayson, Dick's uncle, aunt and cousin respectively.
The story of a one-shot comic taking place after the original Toy Story revolved around Speck, the puppy Andy got at the end of the movie. This was written years before Toy Story 2, which introduced his canon equivalent, Buster.
In DA's Darkwing Duck comics, there was a popular recurring villain named Fluffy, a super-intelligent housecat with a robotic suit of armor, who never appeared in the official canon.
The early Doctor Who comics had John and Gillian, the Doctor's other grandchildren, and other, less well-remembered companions. Doctor Who Magazine comics had Sharon (companion to the Fourth Doctor), Sir Justin and Angus "Gus" Goodman (companions to the Fifth Doctor) Frobisher (long-running companion to the Sixth, and briefly, Seventh Doctors), Izzy, Fey, Kroton (a rogue Cyberman) and Destrii (companions to the Eighth Doctor) and the Tenth Doctor has Majenta Pryce. Other comics have featured other companions. The comic in Doctor Who Adventures has Heather McCrimmon and Wolfgang Ryter as companions to the Tenth Doctor.
As well as companions, the DWM strip featured other recurring characters such as Max Edison and Colonel Muriel Frost. The latter might be a Canon Immigrant as "Major Frost" in "Aliens of London", in which case she's dead.
Marvel loved to do this in the 1980s with their adaptations from other media. They seemed to enjoy introducing relatives to certain characters; fathers, sons, and brothers, ESPECIALLY brothers! In Dino Riders, Questar's brother pops up at the end of the 1st issue. In Defenders of the Earth, The Phantom has to confront his evil brother.
Various Transformers comic lines have loads of this, introducing original Transformers, like Primus, Scrounge and Jhiaxus that never were in the toylines before. And with the... eagerness Transformers fans display, many of these characters reach Canon Immigrant status, earning their own toylines.
Ninja Turtles again: IDW's Teenage Mutant Ninja Turtles book, while focusing mostly on characters brought in from other TMNT incarnations, has also introduced a handful of new characters of its own, such as cat mutant Old Hob, who was mutated at the same time as the turtles; and Alopex, a mutant arctic fox.
DC Comics' The Powerpuff Girls book introduced the Powerpunk Girls, who are popular in fan fiction. This one is rather debatable, since they were meant to show up in the TV series. But due to over-blowing their budget, the creators weren't able to make the episode and gave it to DC for a 50th issue anniversary special.
Shazam: The Monster Society of Evil (and its sequel series, Billy Batson and the Magic of Shazam!) featured a blonde Lois LaneExpy named Helen Fidelity, who was in a Two-Person Love Triangle with Captain Marvel, and who (to date) has never appeared in the main Fawcett and DC Comics continuities.
Malibu Comic's Street Fighter had Nida, a woman who blames Ryu for her father's death. If the comic had continued it would have turned out to have been an evil clone created by M. Bison.
If The Smurfs comic books are considered the official canon (and they most likely are in Europe), then the American-produced cartoon show and film series have characters that are considered foreigners to it, which also include the human allies of the Smurfs as well as the villains created by Hanna-Barbera and Sony Pictures. For the Smurf characters of all three continuities to be present together, they would have to appear in Merchandise-Driven stories such as the Smurfs Village game app for the Apple iPad and Android.
For The Simpsons comic series, we have Apu's nephew Jamshed.
The Night Fury dragons are actually found only in the film adaptation of How to Train Your Dragon. In the books, Toothless was much smaller and looked more like a Terrible Terror dragon than a Night Fury dragon.
Lucifer in Cinderella. For that matter, a good number of animal sidekicks in Disney movies count.
Averted with Djali, who is indeed in Victor Hugo's original novel.
Li Mei, the Mandarin's descendant from The Invincible Iron Man. Though a similar character named Sasha has been introduced in the comics as the Mandarin's daughter, it's unclear if the two are intended to be the same person.
The 1991 film adaptation of The Little Engine That Could, we get Chip the bird (a friend of the title character), a doctor engine, a Jerk Ass control tower, and a human boy's skeptical older sister.
The Lord of the Rings trilogy added various tertiary characters as well as additional individually identified bad guys. To this end, one of the Uruk-Hai in Fellowship of the Ring was given more importance and called "Lurtz". Similarly, Gothmog fills this role in Return of the King. Technically, the latter was in the book, but only mentioned in passing, and it's unspecific whether he's even an orc. The movie expands on this by making him a big nasty orc with what appears to be Proteus Syndrome.
Yet another Teenage Mutant Ninja Turtles example; as in the original cartoon, they outnumber the actual canon characters. Tatsu, (TMNT I and II), Tokka, Rahzar (TMNT II), all the introduced characters in TMNT III and Max Winters (TMNT) are the most notable.
Tom Sawyer and Dorian Gray in The League of Extraordinary Gentlemen. Although those characters were alluded to in the original material, they were never seen and certainly were not main characters. The film also features an Expy for the Invisible Man because they couldn't get the rights to the H. G. Wells character.
Clue had Wadsworth the butler. Wadsworth can also be considered a result of Third Option Adaptation; that way, at least one of the endings - the last to be shown on editions that show all three in sequence, implying its canonicity - would have a culprit who wasn't one of the playable characters.
Robert Hammond, a U.S. Senator and the father of Hector Hammond, in Green Lantern.
In Supergirl, all of the major characters save Supergirl herself, her parents, Jimmy Olsen, and Lucy Lane. Another (sort of) exception is Principal Danver. In the comic book, the Danvers are Supergirl's foster parents on Earth. Perhaps this character (or one of his relatives) was supposed to adopt Supergirl in a sequel that was never made.
In the first one, Blade and Deacon Frost were the only comic characters. Blade's quasi-love interest and all of the named vampires were created for the movie.
In the second, Blade was essentially the only comic character to be featured in the movie. While there was a team called the Blood Pack in the original material, the individual members featured in the movie were new.
Like the Blood Pack, the third film featured a team of vampire hunters that were lifted from the comics called Night Stalkers, but Hannibal King was the only member taken from the comic series. Whistler did not have a superhero daughter and the rest were completely new characters. Also, while Marvel Comics did have a version of Dracula who has fought Blade many times, this film featured a version that was taken in a different direction.
While the Strategic Scientific Reserve is made up of established comic characters and is one of the MCU's in-universe predecessors to S.H.I.E.L.D., the organization itself fits this trope, as it was created solely for the movie.
The Transylvanians fromThe Rocky Horror Picture Show. The original stage version used "phantom" back-up singers who weren't part of the story, not party-goers.
Colonel Hardy and General Swanwick don't exist in the comics Man of Steel is based on. Though Swanwick might be considered a stand-in for Lois Lane's father General Sam Lane, who filled the military brass role in Superman: Secret Origin. In addition Colonel Hardy is referred to by the codename "Guardian" near the end of the movie. Colonel Hardy is seemingly a replacement for Jim Harper, aka Guardian.
Although Toho's Godzilla franchise features plenty of giant mutant insectoid monsters, the makers of this film decided to introduce the Mutos as an original set of this sort of creature for Godzilla to fight.
The Teaser Trailer Monster only appeared in the SDCC teaser trailer, but did not appear in the final film. There is, however, a small nod to it in the form of a peculiar and brightly coloured millipede in the Janjira zone.
The first StarCraftExpanded Universe novel, Liberty's Crusade, was a Pragmatic Adaptation of the first game's Terran campaign. Its viewpoint character is a journalist named Michael Liberty who is embedded with then-Colonel Edmund Duke's Alpha Squadron (partly to hide him from Confederate magnates he pissed off with his previous story). With the exception of Queen of Blades (which covers the SC Zerg campaign from Jim Raynor's viewpoint) and Speed of Darkness (which focuses on a group of Confederate Marines on Mar Sara who were Heroes of Another Story to the Player Character of the Terran campaignnote They fought a holdingaction against the Zerg at the same time as the third Terran mission, which diverted substantial forces away from the PC's troops and enabled their escape.), the other books don't touch the game campaigns, inevitably creating dozens of Canon Foreigners.
Inevitable in the Star Wars Expanded Universe, since its timeline spans roughly 100,000 years of which the movies comprise about forty.
Clark's friend and sidekick Chloe Sullivan. Lampshaded when the Legion of Super-Heroes visit and have knowledge of all of Clark's canon friends but none of her.
The Arrow TV series gives Ollie Queen a teenage sister named Thea and a partner named Diggle. Also Malcolm and Tommy Merlyn (though Malcolm is closer to the comic character Merlyn the Archer) and Dinah Lance's sister. Tommy and Diggle have since become Canon Immigrants in the New 52.
How much you consider Power Rangers an adaptation of Super Sentai is variable (depending on the season. You get some that are all their own and just borrow some fight footage, and some that are shot-for-shot remakes.) but in addition to non-sentai supporting casts, Power Rangers Lightspeed Rescue has the Titanium Ranger, a Sixth Ranger that doesn't exist in any form in the original series, which it is otherwise quite similar to. The Spirit Rangers may or may not count (the characters existed; that storyline and their getting shiny suits didn't.)
Power Rangers RPM has an attack with the wheels of the suits that didn't appear in Go-onger.
Except that it becomes Canon Immigrant in Gokaiger. No sign of the Burst Attacks yet, though.
The show also introduced "Mio Kuroki", a mysterious and malicious teenager who enjoyed making the senshi's lives miserable. While described as a "shadow" of Beryl (who could more directly interact with the cast), she seemed to have a degree of free will.
Insofar as we can call hundreds of years of legend "canon", the 1980s series Robin of Sherwood introduced the idea of including a Saracen to Robin Hood's outlaws, a figure that was popular enough to be included in Kevin Costner's Prince of Thieves and again the BBC's 2006 Robin Hood. The latter television series also introduced original characters Isabella (Guy of Gisborne's sister) and Kate (Locksley village girl) as Affirmative Action Girls after Marian and Djaq (who ironically, was the Saracen) were written out.
Ros, who serves equally well as Ms. Fanservice and The Watson, for especially thorny bits of exposition, and additionally fills the (relatively minor) roles of Kyra and Alayaya in the books. George RR Martin has said he intends to give her a cameo in a later book, so she may soon get promoted to Canon Immigrant.
Talisa Maegyr, who replaces minor character Jeyne Westerling as Robb Stark's love interest.
Kovarro, one of Daenerys's bloodriders. He has elements from Dany's other bloodriders, favoring the arakh like the book version of Rakharo. There is an also an older bloodrider named Malakho who is seen amongst other Dothraki.
The Spice King from Qarth. There is an Ancient Guild of Spicers in Qarth, but no prominent members directly interact with Dany.
A lot of characters in The Walking Dead, a large amount of characters from the show never appeared in the comics including Daryl Dixon, Merle Dixon, T-Dog, Beth Greene, Leon Basset, Gary Taylor, Patty Taylor, Jacqui, Ed Pielter, Morales, Dr. Jenner, Guillermo, Jimmy, Dave, Tony, Randall, Nate, Sean, Oscar, Tomas, Big Tiny, Milton Mamet, Rowan, Haley, Tim, Shupert, Crowley, Gargulio and Sasha.
The Vampire Diaries has a few, mostly family members of canon characters. Alaric is a good example, and Jeremy qualifies as well — he's too far different, and fills such a completely different role in the story, from Elena's younger sister in the books that he can't be considered the TV version of her.
True Blood almost exclusively uses characters based in some way off characters from the books, with the prominent exception of Jessica Hamby, Bill's vampire progeny.
The iconic gumball machine in The Twilight Zone was not taken from an existing episode of the series.
The most prominent toy in Stern Pinball's Batman game (based on The Dark Knight) is a large yellow construction crane that swings out over the playfield — and is nowhere to be found in the movie.
The Adventures of Superman introduced Jimmy Olsen, Inspector Henderson, Kryptonite and the names "Daily Planet" and "Perry White."
The BBC Radio 4 series The Rivals adds Inspector Lestrade from the Sherlock Holmes books to the adventures of various other Victorian detectives, creating a sort of Shared Universe from unrelated stories.
Whenever Clue comes out with an expanded version or spinoff based around Boddy Mansion (as opposed to say, Star Wars or The Simpsons) it seems traditional to add a bottle of poison as a weapon, as well as the appearances of Madam Rose, Sgt. Grey, M. Brunette, and Miss Peach as extra characters.
The mage/planeswalker Jodah in Magic: The Gathering was created by Jeff Grub for the novelizations of the plot of The Dark and the Ice Age cycle of books, created in 1999 (where the sets were created in 1994-5). He'd prove popular enough to get an Avenger card in Planar Chaos.
The Neon Genesis Evangelion RPG game The NERV White Paper introduced Maria Vincennes, a female EVA pilot from America.
The Most Happy Fella, adapted from the straight play They Knew What They Wanted, built the comic Beta Couple of Cleo and Herman out of whole cloth, and gave Tony a sister Marie to object to his marriage. (In the original play, the objector is the Catholic padre; also, Amy jokingly refers to herself at one point as 'Cleo', playing off Antony and Cleopatra.)
Several characters in As You Like It (which was Shakespeare's adaptation of the Thomas Lodge novel Rosalynde), most importantly Touchstone and Jacques (of "All the world's a stage" fame). The rest of the Canon Foreigners in the story are all related to them in some way: Jacques, being a cynicalphilosopher, gets a scene where he plays off the idealistic, music-loving "Amiens", while Touchstone's subplot necessitates the inclusion of his love interest, "Audrey, a country wench", a country priest named "Oliver Mar-Text", and "William", Audrey's ex-boyfriend.
Star Wars: Galaxies introduced the Force Sensitive Village of Aurilia, Vader's failed apprentice Mellichae, The Meatlumps and their King to name a few. These canonical additions, among many others, have been cited in other Star Wars mediums.
Another Star Wars canon foreigner, Kyle Katarn is perhaps one of the most prominent video game-based canon additions from the Jedi Knight series who has spawned his own books and action figures.
The original characters in the Street Fighter EX series are owned by Arika, the company that developed the game, instead of Capcom. When the developers realized this, they retconned the backstories for Doctrine Dark, Pullum Purna, and Garuda to distance them from the canon Street Fighter cast (for example, Garuda, who was originally a demon created by the Satsui no Hadou, was now a manifestation of evil energy). Blair Dame and Allen Snider were also put in a non-Capcom related fighting game called Fighting Layer.
Sisyphus the mutant beetle from the Genesis version of Tournament Fighters was never in any other TMNT media, although its easy to think otherwise due to the number of anthropomorphic characters that were introduced to the toyline in later years.
The first game for the NES however, mostly used such familiar characters as: Those chainsaw guys, people made of fire, weird giant porcupine/armadillo hybrids, machines that have never been seen anywhere else before or since.
The various third-party Mega Man (Classic) productions add characters that would never be seen again — all of the bosses from the PC games (.EXE renamings and coincidentally same-named bosses in later games notwithstanding), several characters from the Ruby-Spears cartoon, Akane and Yuuta from the OVA, Dreamwave's three "boss characters", etc.
The insidious House Ordos from the Dune RTS games by Westwood Studios.
Turned on its head in The King of Fighters 2002 Unlimited Match: the new character Nameless was created specifically to take the place of K9999 from KOF 2001, who was such a blatant ripoff of Tetsuo Shima that SNK Playmore had trouble using him in later games.
The King of Fighters EX and Maximum Impact sub-series, both falling squarely under Alternate Continuity, feature their own original faces, more than a few of whom could feasibly be inserted into the main canon with little (if any) alterations to their backstory. One example is Xiao Lon, the half-sister of Hizoku assassin Duo Lon, who was created with the intention of loosely linking together the original titles and the MI series while avoiding plot holes (her debut in Maximum Impact: Regulation A, an Updated Re-release of MI2, also featured Ash Crimson, a former teammate of Duo Lon's from the current "Tales of Ash" arc).
Reika Kirishima, one of the playable characters in Castle Of Shikigami III, was originally the star of her own Laserdisc and Sega CD game called Time Gal. She was also a playable character in Elevator Action Deluxe.
Wolfduck was a villain that only appeared in the Darkwing Duck video game.
The Metal Gear canon excludes all the original characters from Metal Gear: Ghost Babel and the Metal Gear Ac!d games. If you wish to go further, there's also Twin Shot, one of the replacement bosses from the NES version of the original Metal Gear, as well as John Turner and Nick Myer, Snake's FOXHOUND comrades from Snake's Revenge (as well as the "Metal Gear 2" mecha from the same game).
Teliko and Venus from the Metal Gear Ac!d games did, however, make cameo appearances as playable characters in the canon game Metal Gear Solid: Portable Ops. In that game, they were described by the other characters as 'aliens'.
Definitely Vermon CaTaffy and Higharolla Kockamamie from the NES Metal Gear games. Although neither character actually existed to begin with.
One of the more extreme examples would be Nicole-458 from Dead or Alive 4, who doesn't appear in any work from the Halo universe she comes from. She's supposed to be a member of the second class of Spartan-IIs, which happens to be one of the few remaining elements from I Love Bees that neither Bungie nor 343i seem to have yet truly adopted as canon.
In Batman: Arkham Asylum, Batman meets in the titular asylum canon foreigners Frank Boles, Doctor Young, and Quincy Sharp. As canon foreigners, they are allowed to be killed, as Boles and Young found out when they stopped being useful to the Joker...
Spider-Man: Shattered Dimensions has a few, mostly in the form of the Hammerhead from the Noir universe, (the developers said that he felt like a perfect fit and he did fit quite well), 2099 Hobgoblin, and a female Dr. Octopus from 2099. There's also the DS versions, which have Noir Calypso and 2099 Silvermane.
X-Men: Destiny revolves around three teenage mutants created exclusively for the game: Aimi Yoshida, Adrian Luca, and Grant Alexander. Aimi is the daughter of Sunfire, who is an actual character in the X-Men and Uncanny Avengers books.
2nd Impression, a lesser known Evangelion game for the Sega Saturn, had Mayumi Yamagishi. She was the Mega Nekko before Mari came around.
In her Resident Evil novelizations, S.D. Perry introduced Trent, a renegade member of the Umbrella board of directors. His role was to fill all the glaring Plot Holes in the games by pulling strings from behind the scenes and assisting the heroes while sabotaging Umbrella's plans.
The two original Resident Evil novels, Underworld and Caliban Cove, were written back before the release of Resident Evil 3: Nemesis. Two of the characters introduced therein, John Andrews and David Trapp of the Exeter S.T.A.R.S. unit, have a small fan following and occasionally appear to this day in fanfiction.
Due to being retconned, anything having to do with the original SNES Star Fox and the unreleasedStar Fox 2 were rendered non-canon. Two new pilots from 2, Fay and Miyu (a poodle and a lynx, respectively), are considered foreigners. With them is Fara Phoenix from the Nintendo Power comic adaptation of the original game.
All the main characters in Discworld Noir. Canon characters such as Gaspode and Nobby Nobbs are limited to secondary roles. There is certainly no indication in the books that Lewton, or even the profession of Private Detective, exists.
The Simpsons Arcade Game gives us all the bad guys in the game except for Mr. Burns, Smithers, the wrestler boss, and the drunk boss.
The fan-made Streets of Rage Remake gives us the female ninja Rudra, who serves as a boss character (depending on which path you take in the story) and is also an unlockable character. Interestingly, she started out as a joke sketch which the artist posted on a forum and claimed that she was Shiva's sister, but a lot of fans didn't get the joke and thought she was real. During the fan-remake's development, Rudra was going to actually be Shiva's sister, but prior to the final draft's development and release the creators went in a different direction with her, turning her into more of a mercenary character who works for the Syndicate as a hired assassin.
In War in the North, there's the main party of Andriel the Elf, Eradan the Ranger, Farin the Dwarf and their Great Eagle companion Beleram. There's also the Big Bad Agandaűr, one of the chief lieutenants of Sauron.
Technically speaking, Agandaűr could be interpreted as an OC Stand In given that he matches the description of a messenger who knocks on King Dáin's door in Fellowship of the Ring.
The Lord Of The Rings The Third Age gets the same treatment with their own main party: Berethor the Gondorian soldier, Elegost the Ranger, Hadhod the Dwarf, Eaoden the Rider of Rohan, Morwen the Shield-maiden, and Idrial the Elf.
Then there's Battle for Middle-earth II. Both the original and The Rise of the Witch-King. Especially for the Evil Armies - including the Goblin King Gorkil, Hwaldar the Wildman serving under the Witch-King, Rogash the troll, and Karsh a celebrated Hero turned Leader of the Great Plague.
The 2003 video game The Hobbit, also made by Sierra Entertainment, has Balfor, a Dwarf; Lianna, an Elf; and Corwin, a man.
The American release of Super Mario Bros. 2 was an altered version of a non-Mario game, Doki Doki Panic. Several of the enemies featured, like the Shy Guys and Snifits, were later used in Yoshi's Island, and more frequently in the Mario franchise from then on.
The multiplayer-focused RaymanSpin-Off game Rayman M introduced the characters Tily and Razorwife and a new robo-pirate model, Henchman 1000, none of whom have made any appearances in the main series.
Ultra Fast Pony is an abridged series that nevertheless has a few original characters thanks to creative editing. There's Snuggle Berry, who's referred to a few times but never appears on-screen—and dies in the same episode she was introduced in. There's also Mutation: in UFP she's a separate character, but in the original canon she was just a shared secret identity.
The King of this trope would have to be Sonic the Hedgehog. Sonic Sat AM, has the most memorable ones. Princess Sally, Bunnie Rabbot, Rotor the Walrus, Antoine, Uncle Chuck, and Snively became amazingly popular.
It's worth noting that the Freedom Fighters were originally based roughly off the small captive animals of the original games, even retaining their western names. However the concept was revamped before production and only a redesigned Sally Acorn (aka "Ricky") remained (though Rotor and Bunnie are arguably based off of Joe Sushi and Johnny Lightfoot respectively). Interestingly some of the Freedom Fighters (including the remodelled Sally for the show) cameoed in Sonic the Hedgehog Spinball and were intended to be playable characters in canned titles, making for a somewhat complex Canon Immigrant.
"This X-23 character is pretty popular among kids ... we should bring her into comics."
"Let's make her a child prostitute!"
Spyke is a sort of example. A character with similar powers named Spike appeared in X-Force, while a canonical nephew of Storm was introduced in Black Panther. His name is David Evan Munroe (his middle name is a Shout-Out to Spyke, whose name was Evan), but it hasn't yet been established whether or not he's a mutant.
Harry Grimoire, wizard in training and friend of Felicia, of the ill-fated Darkstalkers cartoon. While he looks like a total ripoff of Harry Potter, he does in fact pre-date Rowling's work. Also, there is Hairball, Sasquatch's nephew, who bravely fended off Demitri. Klaus, Victor's stout butler also qualifies. Terramon, the health inspector and Pyron's brother from the last episode. Dracula and Van Helsing may or may not count, as they are Public Domain Characters.
Red Claw, Summer Gleeson, Joan Leland, Maven, Baby Doll, Roland Daggett, Calender Girl, Kyodai Ken, and H.A.R.D.A.C. from Batman: The Animated Series, plus Harley Quinn, Renee Montoya, Gray Ghost, Roxy Rocket and Lock-Up, five successful Canon Immigrants. There's also various one-off supporting characters like Veronica Vreeland or Batman's mechanics Earl and Marva Cooper.
Ethan Bennett, Chief Angel Rojas, the Kabuki Twins, Temblor, Rumor, and Scorn (but not Wrath, who was just very obscure) from The Batman. Ellen Yin may seem like this, but she is actually a Race Lift of Ellen Yindel, the obscure female police commissioner from Batman: The Dark Knight Returns. There's also Smoke and Blaze, two Distaff Counterparts of Mirror Master and Firefly.
Everyone in Batman Beyond except Bruce Wayne, Barbara Gordon, and Mister Freeze. Prominent examples would be Terry McGinnis and his family, Max Gibson, Barbara's husband Sam, and every member of the JLU except Superman and Big Barda.
Most of the villains from Static Shock were created for the series, with the major exceptions being Hot-Streak and Rubberband Man. Richie Foley (AKA Gear) and She-Bang were also created for the show, though the former was a Captain Ersatz of Rick Stone, Static's buddy from the comics.
The Geek, a female child companion to Sam & Max: Freelance Police, was created for the kid-friendly cartoon series. She was, however, created by the creator of the original comic books, with a light dash of Executive Meddling: originally he created The Geek as a male character, intended to make the series more kid's-TV-friendly, but when the network suggested Max be made female, he opted to make The Geek female instead. (A much more acceptable compromise.)
Blade's mentor, Whistler, in Spider-Man: The Animated Series, where his two main functions are to exposit about Blade and vampires and to convince Blade to trust and cooperate with the other heroes. In fact, Whistler was created for the animated series and reused in the movie, and is an interesting example of canon foreigner existing in two mediums without becoming a full Canon Immigrant.
3/4 of the characters from The Super Mario Bros. Super Show, The Adventures of Super Mario Bros. 3, and Super Mario World cartoons have never been (and likely will never be) seen in the games. Most notably Oogtar and every other caveman character inhabiting Dinosaur Land in Super Mario World, every character based off a movie or story in Super Show, and every single character from the 'real world/Earth' in the first two cartoons.
Justice League and Unlimited used a bunch of characters who split the difference between Canon Foreigner and Expy:
Hro Talak is Hawkman, only evil. Except he can't be Hawkman, because the real Hawkman (Carter Hall/Katar Hol) appeared in a later season. DC didn't allow the writers to make Hawkman evil. Hro Talak is an anagram of Katar Hol.
Devil Ray is practically Black Manta, only he's a nemesis of Wonder Woman instead of Aquaman (who could not be used in the later seasons due to the unsold Aquaman pilot).
And in a cross-company example, the Justice Lords are versions of the JLA who became corrupted by their abilities and all but conquered Earth for "the greater good", only to be betrayed by their Batman. In other words, the Squadron Supreme.
For The Fairly OddParents, the Copper Cranium and the Gilded Arches show up only in the Crimson Chin webtoon. Arches later appeared in a video game. King Oberon, Queen Titania, and the Shadow only appear in the video game Shadow Showdown
Eva Skinner/XANA and about ten other one-off characters are introduced in the Code Lyoko novels.
The Legend of Zelda animated series had several of these, including Zelda's father King Harkinian, the fairy Spryte, and every other character to appear who wasn't Link, Zelda, or Ganon.
While Spryte herself didn't become a Canon Immigrant, the idea of Link having a fairy companion began here, and has been seen in a few games.
Mostly averted in The Spectacular Spider-Man as much as any adaptation probably can—the creators decided that every named character should be someone from Spider-Man canon, and more or less stuck to it, even with minor characters like Norman Osborn's assistant, the high school drama teacher, etc.
Averted with Artemis; after much confusion by fans, she turned out to be an adaptation of Artemis Crock, the minor comics villainess Tigress.
A proper example would be the Terror Twins, a pair of teen villains created for the show, and Green Beetle, a Martian with the same sort of Scarab used by Blue Beetle.
The tie-in comic gives Robin three new relatives: a cousin and aunt who die along with his parents, and an uncle who survived, but was crippled and couldn't care for him. For bonus points, Word of God reveals that Robin is named after his uncle, who went by Rick— offering an explanation for why a show taking place "now" would feature a kid named Dick.
Ruby, the red ninja created for Mortal Kombat: Defenders of the Realm. Though a red female ninja named Skarlet was eventually introduced in the video game canon, she has nothing in common with Ruby other than the basic color motif.
Superman: The Animated Series had quite a few with Volcana, Luminus, the Preserver, Sgt. Corey Mills, General Hardcastle, Detective Kurt Bowman, Darci Mason, Angela Chen, and Unity. Mercy Graves and Livewire started here and became Canon Immigrants.
Heroes On Hot Wheels was actually based on a French comic book called Michel Vaillant. The characters of Frank (Michel's younger brother), Hanna (Frank's photographer girlfriend), Quincy (Team Vaillante's mechanic) and Fox (one of Team Leader's racers) were not in the original comics.
DuckTales primarily based off the Carl Barks Uncle Scrooge comics, had Launchpad McQuack, Mrs. Beakly, Duckworth (Scrooge's butler is always some stock character in the comics), Gizmo-Duck, Bubba Duck, and Doofus Drake. There was also Webbigail Vanderquack, who was an expy of Daisy Duck's nieces from the comics.