[[quoteright:307:[[RuleOfCool http://static.tvtropes.org/pmwiki/pub/images/doomvader-resized40percent.jpg]]]]
[[caption-width-right:307: [[HilariousInHindsight Considering that now they]] [[Creator/MarvelComics are]] [[Franchise/StarWars both]] [[Creator/{{Disney}} owned by the same company]]...[[note]]Barring the fact that the ComicBook/FantasticFour film rights currently belong to Fox.[[/note]] ]]
->'''Jigsaw:''' [[TheReasonYouSuckSpeech You wallow in hypocrisy, Angus. Your life has been dedicated to nonviolence, which you advance by jerry-rigged poisons and explosives, pretending that using one form of violence over another makes you better than others]]... Well, now it is time to see how far you're -- did you just turn your manacles into laser beams?\\
'''[=MacGyver=]:''' Yep.\\
'''Jigsaw:''' ...[[OhCrap Crap]].
-->-- Hypothetical ''Series/MacGyver''-''Film/{{Saw}}'' crossover.

Having a CrossOver between two related shows is one thing -- it's not inconceivable that some of the ''Series/{{Cheers}}'' cast should turn up in ''Series/{{Frasier}}'', is it? Or that characters from ''Series/{{JAG}}'' could turn up on ''Series/{{NCIS}}''. Or that the ''Series/{{CSI}}'' team might help out the guys in ''Series/{{CSINY}}'' every now and again.

What happens when [[TheViewAskewniverse Jay and Silent Bob]] turn up in ''Film/{{Scream 3}}''? Or Cliff and Norm from ''Series/{{Cheers}}'' book into ''Series/StElsewhere'' for medical attention? Or a police officer from the grittily realistic ''Series/HomicideLifeOnTheStreet'' arrests Fox Mulder of ''Series/TheXFiles''? Or the CSI team finds a corpse in a hotel that isn't a corpse, just Series/{{Angel}}? Well, then you've got yourself a different kettle of fish altogether. And to add insult to injury, the fish are probably from ''WesternAnimation/FindingNemo'' and ''Disney/TheLittleMermaid''.

There are a few reasons why this happens. Sometimes it's because both series are owned by the same network or company, and it wants to improve the ratings on the one show by having the cast from the more popular show appear in it. Sometimes it's because both shows share writers or producers and they think it would be amusing to link the two. And sometimes it's just because [[RuleOfCool someone somewhere thought it would be cool]].

Most crossovers of this kind are between properties that are owned by the same company or person, which makes legal wrangling easier. But sometimes characters will cross over into another company's properties, like the occasional events from rival comic book firms Creator/DCComics and Creator/MarvelComics.

It makes quite a difference whether the crossover reveals that the characters have supposedly been sharing the same world the whole time; or if they're "just" from AnotherDimension. While not as big a deal if both series are "relatively" realistic, such as Crime Dramas, if each show has its own version of fantastic events a la {{Fantasy}} or ScienceFiction; then the implication is that these elements have been [[FantasyKitchenSink existing side by side the whole time, unaware of each other.]] It also makes for some great FridgeLogic. "Hey, Problem A for Cast B is no big deal, if Cast A and B are friends, why don't they just ask for help?" Of course, SupermanStaysOutOfGotham, and ReedRichardsIsUseless as always.

For more information and examples, see [[http://www.poobala.com/crossoverlist.html Thom Holbrook's Crossovers and Spin Offs Master List]], which documents all known crossovers between TV series, except for cartoons. With this information, the site has been able to identify no fewer than 38 contiguous TV "universes" (as of March 2008) which are home to widely disparate (and apparently unlikely) combinations of series from different eras and networks. For instance, see Holbrook's [[http://www.poobala.com/crossoverlistb.html#G2 "Group 2"]] -- ''ninety-four'' series (as of March 2012) ranging from ''Series/SixFeetUnder'' and ''Series/EverybodyLovesRaymond'' to ''Series/LawAndOrder'' and ''Series/TheXFiles'', taking in ''Series/{{MASH}}, Series/CopRock'', and ''Series/HomeImprovement'' along the way. Thanks to the baroque web of interconnections and crossovers, it is suggested that these shows all inhabit the same universe. (Holbrook also discovered the "Creator/JeanClaudeVanDamme is dead" plague that poses a grave threat to any future crossovers including ''Star Trek'' and other Group 10 shows.)

It has been noted on this and other sites that the web of crossovers connects many shows, directly or indirectly, to ''Series/StElsewhere''. Since that entire series was shown in its final episode to be the fantasy of an autistic mental patient, it has become a {{Stock Epileptic Tree|s}} that all of reality is AllJustADream of an autistic mental patient. In the words of Creator/DwayneMcDuffie, one of the executive producers of ''WesternAnimation/JusticeLeague'', "The last five minutes of ''Series/StElsewhere'' is the only television show, ever. Everything else is a daydream."

For the {{webcomic}} equivalent of the TV crossover list, see the [[http://crossovers.dragoneers.com/ Webcomic Crossover & Cameo Archive]].

For a {{fanfic}}tion equivalent, see MegaCrossover and RuleFifty. (The map needs to add ''[[VideoGame/CityofHeroes City of Villains]]'', but nobody's complaining really.)

When this trope happens with three or more series instead of two, it's a MassiveMultiplayerCrossover. When the two settings are blended so as to be one unified setting that partakes of elements from both, that's a FusionFic.

When each others' works of fiction appear in-universe ''as fiction'' in a stable fictional loop, that's MutuallyFictional. When a work of fiction ''itself'' appears in its own story, that's RecursiveCanon.

Compare {{Crossover}}, FakeCrossOver. See also VegasCrossover, {{Transplant}}, FullyAbsorbedFinale, GuestFighter, and UltimateShowdownOfUltimateDestiny.

----
!!Examples:

[[foldercontrol]]

[[folder:Anime & Manga]]
* Part of the Red Ribbon Army story arc on ''Manga/DragonBall'' had Goku chasing Captain Blue to Penguin Village, the setting of Akira Toriyama's earlier manga/anime, ''Manga/DoctorSlump'', and featured appearances by Arale, Dr. Norimaki, and several other characters. This appeared in the manga and anime (since both shows were made by Toei and aired on Fuji TV); moreover, when ''Manga/DoctorSlump'' was animated again in 1997, a new ''Manga/DragonBall'' crossover was written in.
** Toriyama already did that in ''Dr. Slump'' itself: there was one chapter where the characters traveled to Wonder Island, the set of the titular manga (and Toriyama's very first published work).
* The ''VisualNovel/{{Air}}''/''VisualNovel/{{Kanon}}'' crossover manga. (''KeyVisualArts'')
* Apparently mostly because the author of ''Manga/FairyTail'' really liked ''Manga/FlunkPunkRumble'' they made a crossover called ''[[http://www.mangafox.com/manga/fairy_megane/ Fairy Megane]]''.
** That the author of ''Manga/FlunkPunkRumble'''s favorite author happens to be the author of ''Manga/FairyTail'' probably helped, as well a former assistant of his. What's most stunning of all is that despite being SERIOUSLY WTF, it actually ain't half bad.
** ''Fairy Tail'' also had a crossover with the story Mashima wrote before it, ''Manga/RaveMaster''. The Jiggle Butt gang appeared in the anime as well.
* The ''VisualNovel/FateStayNight X MagicalGirlLyricalNanoha'' and ''MagicalGirlLyricalNanoha X Manga/FateKaleidLinerPrismaIllya'' collaboration manga that both started in the March 2010 issue of ''CompAce'' magazine.
* And then there's the ''Manga/DetectiveConan''/''Manga/LupinIII'' crossover TV special...
** This was because the anime adaptations of both series were produced by Creator/TMSEntertainment.
* ''Manga/DragonBall'' and ''Manga/OnePiece'' in ''Cross Epoch''.
** At one of the Jump Fiesta events they featured another crossover of Luffy and Goku going up against Eneru above the city of Tokyo. Other characters get short cameo and Ryotsu of ''{{Kochikame}}'' made an appearance (as seen [[http://www.youtube.com/watch?v=CYmzjou2LMU here]]). They would later do this again only this time against Arlong and ''Manga/AstroBoy'' was thrown into the mix.
* ''LightNovel/{{Slayers}} VS [[Manga/SorcererStabberOrphen Orphen]]''
* Rodimus's backstory in ''Anime/TransformersEnergon'' states that he left Cybertron with a band of Autobots and "traveled into the future", which reflects the ending of ''Transformers: The Headmasters'', in which he ventures off into space to find/found a new home planet.
* To promote the JumpSuperstars game for the DS, a manga was included for those who preordered drawn by the people behind ''Manga/{{Eyeshield 21}}''. A standard "sucked into a world to defeat the villain" affair but damn if its not cool seeing Manga/{{Naruto}}, [[Manga/OnePiece Luffy]], [[Manga/DragonBall Goku]], [[Manga/IchigoOneHundredPercent Toujou]], and Manga/{{Bobobo|boBobobo}} work with Seta to kick [[Manga/DoctorSlump Dr. Mashrito's]] butt. [[http://www.mangafox.com/manga/jump_super_stars/v01/c001/1.html Check it out here.]]
* It's not much, but in G Gundam, during the finale episode where all the world's Gundams had banded together to fight the Dark/Devil Gundam, you can see Gundams from other series in the mob. For example, both the standard RX-78-[=GP01=] and the RX-78-[=GP01=] Full Vernian, the Wing Gundam, RX-78-2, etc. They weren't kidding when the said they had all the Gundams!
* In-universe example in ''{{Manga/Bakuman}}'': ''Crow'' and ''+Natural'' are two manga drawn by the same artist, the former about a crow-man (or something like that, the premise is never stated), while the latter is about a kid who finds he's psychic. Fast forward to a time where ''+Natural'' is doing poorly while ''Crow'' remains among the most popular of ''Jump'', and you get the protagonist of ''Crow'' showing up in ''+Natural'', saying he's also a psychic. (We only know so much about the [[ShowWithinAShow Shows Within A Show]], so we can't be sure that they're in different continuities, but given the plots and the characters' reactions, this seems to be the case.)
* ''LightNovel/BokuWaTomodachiGaSukunai'' and ''LightNovel/SeitokaiNoIchizon''.
* There's also the ''Minky Momo vs. Creamy Mami'' OVA.
* This has become a recent trend with Magazine/ShonenJump manga, and the anime adapted from them.
** ''Manga/{{Gintama}}'' and ''Manga/SketDance'' had a crossover chapter for each manga, and two corresponding crossover episodes.
** Manga/{{Toriko}} and ''Manga/OnePiece'' had two crossover episodes (one of which was adapted from a manga crossover).
** And, most recently, ''Manga/OnePiece, ''Manga/{{Toriko}}'', and ''Anime/DragonBallZ'' had a crossover episode, though it obviously had no bearing on the continuity of any of the anime involved.
[[/folder]]

[[folder:Comic Books]]
* [[Series/DoctorWho The Doctor]] showed up in one of the [[ComicBook/BuffyTheVampireSlayer Buffy Season 8]] comics for a panel (along with Rose). Suddenly London's forgetfulness makes sense.
* Beginning with ''[[Franchise/AlienVsPredator Predator vs. Aliens]],'' the two extraterrestrials have done battle (either one-on-one or multiplayer deathmatch) with essentially every superhero ever created, no matter how illogical the match-up. Taken to ridiculous extremes in ''Franchise/{{Superman}} and Franchise/{{Batman}} vs. Aliens and Predator.'' Perhaps the most famous of these stories was ''Comicbook/WildCATs/Aliens'' which actually had an impact on the former's continuity and saw the deaths of several members of ''Stormwatch'' to allow Creator/WarrenEllis to clear the decks to create ''Comicbook/TheAuthority''.
* Despite their rivalry, Creator/DCComics and Creator/MarvelComics have had numerous crossovers between their two companies, leading to meetings between Franchise/{{Superman}} and Comicbook/TheMightyThor and in particular Franchise/{{Batman}} and Comicbook/CaptainAmerica, the two companies main BadassNormal heroes, and also confrontations between heroes and villains from each, such as Spidey taking on the Joker. The whole thing even has a standing HandWave established in the late 1990s, that the Marvel and DC universes will occasionally start to merge on their own, leaving teams from the two inhabiting the same continuity all of a sudden and remembering each other as if it's always been that way. For instance, in the ''Comicbook/XMen/Comicbook/TeenTitans'' crossover, at one point they even discuss bringing in the Justice League ''and'' Avengers to help.
** An interesting example: [[http://30.media.tumblr.com/tumblr_lnacm5QoMK1qkz9yno1_500.jpg X-Men and Teen Titans]]. Starfire learns languages by kissing people, and Nightcrawler thinks ''that's terrific''.
** An unfortunate side-effect of this is that the closest Jubilee has ever come to a serious relationship is with [[Comicbook/RobinSeries a guy who lives in another universe]].
* Some comics by Roy Thomas saw a team-up between Creator/RobertEHoward's ''Franchise/{{Conan|TheBarbarian}}'' and Creator/MichaelMoorcock's ''[[Literature/TheElricSaga Elric of Melnibone]]''. On Elric's side this makes sense, as his home continuity is explicitly one of many parallel worlds.
* Comicbook/JudgeDredd has teamed up with Franchise/{{Batman}} on at least three occasions; given Bats' vigilante status and Dredd's fascist asshole status, there was some distinctly TeethClenchedTeamwork on both sides. Dredd has taken on ''Franchise/{{Alien}}s'' and the ''Franchise/{{Predator}}'' as well. And in ''ComicBook/TwoThousandAD'' publications themselves, Dredd has crossed paths with Johnny Alpha from ''Comicbook/StrontiumDog'' twice (Both of these strips have been created by the same people) and has seen a whole score of cameos from outside characters during the ''Helter Skelter'' story arc.
* ''Comicbook/ThePunisher''
** Punisher met Franchise/{{Batman}} in two one-shot comics: ''Lake of Fire'', where he worked with Post-''Comicbook/{{Knightfall}}'' version of the character (Jean-Paul Valley, aka Azrael), and ''Deadly Knights'', where he got less warm welcome from the original one, Bruce Wayne.
** Punisher was featured in one of the single most bizarre intercontinuity crossovers, ever: ''ComicBook/ArchieMeetsThePunisher''. The Archie EIC at the time admitted the comic came about from him randomly meeting some Marvel guys at a cafe and talking.
* ''[[http://www.viruete.com/articulos/fotos%20articulos/superman-heman/HE-MAN%20vs%20SUPERMAN.jpg Superman/He-Man]]''. It didn't suck as much as you thought it would, chiefly because this was ''before'' the cartoon debuted, and He-Man behaved more like the loinclothed barbarian he was, [[http://www.encyclopedia-obscura.com/printcomicshemansuperman.html and didn't have Orko laming it up.]]
* Creator/DarkHorseComics gave us ''Franchise/{{Tarzan}} versus Franchise/{{Predator}} '''At The Earth's Core'''''.
* Illyria of the ''Buffy Verse'' has appeared in Creator/PeterDavid's ''Fallen Angel''. David also wrote an earlier Illyria-one-shot.
* Top Cow had an extended crossover with Marvel where the companies' characters live in different universes and which is probably in continuity, although several crossovers are pointedly not (like the one where Wolverine gets married to [[Comicbook/{{Witchblade}} Sara Pezzini]]), and a Darkness/Batman crossover which featured an important in-continuity event that affected the Darkness series itself, even though it couldn't possibly be in continuity.
* ''Comicbook/CaptainAtom: Armageddon'' thrusts the DC Comics hero into Jim Lee's Creator/{{Wildstorm}} universe. The mini-series functions as a CosmicRetcon for Wildstorm, and allows those comic readers who generally hated the ridiculousness of ''Comicbook/TheAuthority'' watch them get their heads handed to them.
* ''Film/MarsAttacks the Creator/{{Image|Comics}} Universe!'' ''Comicbook/TheSavageDragon'' actually kept it in-continuity, with an issue that gave a basic overview for those who didn't read it, and continued the story from there with Chicago recovering from the invasion.
* [[Comicbook/GodzillaKingOfTheMonsters When Marvel owned the license]] to Franchise/{{Godzilla}}, he once did battle with ComicBook/{{SHIELD}}, the ''Comicbook/FantasticFour'', ''Comicbook/TheAvengers'', ''Comicbook/IronMan'', and various other {{Creator/Marvel|Comics}} characters.
* Comicbook/ArchieComicsSonicTheHedgehog Super Special #7 crossed over with the entire Creator/ImageComics universe, and it's all in continuity. ''ComicBook/SonicTheHedgehogMegaManWorldsCollide'' teamed up the blue heroes for the first time; while it's considered non-canon for Mega Man, it's canon for Sonic as it served as the comic's CosmicRetcon due to the heaping of ScrewedByTheLawyers the comic was being put through. The crossover with Mega Man and Mega Man X, though, revealed that Mega Man's half ''is'' canon, just that it's in the future.
** Not only has Sonic met those groups, he's also encountered ComicBook/SabrinaTheTeenageWitch a few times. However, because of how Sonic's treated, all of their encounters are considered non-canon.
* When it was originally planned as a four-issue limited series, ''Franchise/{{Transformers}}'' shared the same 616 universe as other Marvel characters. J. Jonah Jameson sent Peter Parker to Oregon to investigate the Transformers ([[MemeticMutation he wanted pictures of Optimus Prime]]) and thus Spidey and the Autobots teamed up. When the title became a monthly ongoing series, however, the crossover was [[CanonDiscontinuity quietly forgotten]]. The ''Franchise/{{Transformers}}'' letter column even asked fans to please ignore the earlier Marvel crossover stories. However, after it became a regular series, the character Circuit Breaker appeared in Secret Wars II, issue 3, indicating some connection between the series and Marvel continuity.
** A company crossover between Creator/{{IDW|Publishing}} and Marvel did have the Avengers and Autobots team up. It's considered ambiguously canon by IDW.
** They also, naturally, had crossovers with their ''Franchise/GIJoe'' comic, to the point that in the "Generation 2" series, they all but merged. Years later, nearly anybody with the license will consider making their own version of the crossover, notably Image's alternate universe which is set during UsefulNotes/WorldWarII, and Devil's Due's 4-part series, which is actually referenced in the Titanium Series toyline.
* The original Mirage ''Comicbook/{{Teenage Mutant Ninja Turtles|Mirage}}'' have crossed over with several other indy comic book characters, most notably [[Comicbook/UsagiYojimbo Miyamoto Usagi]], ComicBook/{{Cerebus}}, the WesternAnimation/WildWestCowboysOfMooMesa, and ComicBook/TheSavageDragon. Plus ''WesternAnimation/TurtlesForever'', crossing over with both TMNT cartoons.
** ComicBook/UsagiYojimbo's appearance in several episodes of both TMNT cartoons. Creator/PlaymatesToys' TMNT toy line even had an action figure for him at one point.
** When Franchise/ArchieComics had the license, [[http://thatguywiththeglasses.com/videolinks/linkara/at4w/21529-tmnt-meets-archie a crossover with the Riverdale gang was inevitable.]]
* The ComicBook/FantasticFour piloted Anime/CombattlerV once. This was when Marvel was publishing a ''Shogun Warriors'' comic book under license from Mattel, who released several Japanese HumongousMecha toys under the banner. The Warriors were fully integrated members of the Marvel 616 universe, though now that Marvel has lost the license...
* ''ComicBook/HackSlash'' has crossed over with several other horror series and characters, including Evil Ernie from ''ComicBook/LadyDeath'', ''Film/ChildsPlay'', ''Film/{{Hatchet}}'', ''BUMP'', and ''Film/ReAnimator''. Tim Seeley, the writer, has said in interviews that he considers '''all''' slasher films to take place in the same universe of canon (justified by some of the entries in the cinema section of this page).
* ''Franchise/StarTrek / Comicbook/XMen'' Almost certainly created so a scene where Bones and Beast were called to with "Doctor [=McCoy=], and both would answer "What?"
* ''Comicbook/TheLeagueOfExtraordinaryGentlemen'' series by Creator/AlanMoore runs off this principle -- that all of fiction exists. So you get [[Literature/KingSolomonsMines Allan Quatermain]] teaming up with [[Literature/TwentyThousandLeaguesUnderTheSea Captain Nemo]], [[Literature/{{Dracula}} Mina Murray]], [[Literature/TheStrangeCaseOfDrJekyllAndMrHyde Dr. Jekyll & Mr. Hyde]], and [[Literature/TheInvisibleMan Dr. Hawley Griffin]]. Then you get characters like Mycroft and Franchise/SherlockHolmes, Professor Moriarty, Literature/JamesBond, Edward Prendrick of ''Literature/TheIslandOfDoctorMoreau'', the Martians from ''Literature/TheWarOfTheWorlds'', Literature/AliceInWonderland, Film/MaryPoppins, an unnamed Dr. FuManchu, and the litany of late-19th century to mid-20th century fiction showing up. There are books out that detail all of the references Moore crams in there. To put the above in perspective... One of the reference books for the first of the League comics has around three pages detailing ''one panel'' of all the things referenced in a museum.
* ''Marvel Team-Up'' #74 (October 1978) teams Spider-Man with [[Series/SaturdayNightLive The Not Ready For Prime-Time Players]] to fight Silver Samurai after Creator/JohnBelushi accidentally gets Silver Samurai's ring. In a similar vein, ''Comicbook/TheAvengers'' once appeared on ''[[Creator/DavidLetterman Late Night With David Letterman]]''.
* Creator/{{Image|Comics}} and Creator/ValiantComics came out with ''ComicBook/DeathMate'' in the 90s, but the less said about that the better.
* ''ComicBook/AmericanBornChinese'' has a subplot that crosses ''Literature/JourneyToTheWest'' with [[Literature/TheBible Christianity.]]
* The first Creator/VertigoComics Winter's Edge special has a ''House of Secrets'' framing story where Rain visits an art gallery in the house that shows her stories from ''ComicBook/TheSandman'', ''ComicBook/TheBooksOfMagic'', ''ComicBook/{{Hellblazer}}'', ''The Dreaming'', ''The Minx'', ''Nevada'' and ''ComicBook/TheInvisibles''. While the first four are part of one continuity, the latter three are all individual continuities, as is ''House of Secrets'' itself.
* The two ''ComicBook/HouseOfMystery'' Halloween annuals may count, because each features a story from ''iZombie'', which hasn't been confirmed to be part of the main DC/Vertigo continuity, unlike ''House of Mystery'' and the other titles that appeared in the annuals (''ComicBook/MadameXanadu'', ''Comicbook/{{Lucifer}}'', ''ComicBook/{{Hellblazer}}'', and ''The Dreaming'').
* The six issue [[Franchise/JusticeLeagueOfAmerica JLA]]/''ComicBook/{{The 99}}'' miniseries.
* Creator/AntarcticPress comics ''ComicBook/GoldDigger'' and ''Comicbook/NinjaHighSchool'' have had frequent crossovers among their [[LoadsAndLoadsOfCharacters various characters.]]
* ''Series/{{Star Trek|TheOriginalSeries}}''[=/=]''Comicbook/{{Legion of Super-Heroes}}'', from Creator/{{IDW|Publishing}} and Creator/DCComics. Interestingly transplants both sets of characters to a ''third'' universe; a [[FusionFic Legion-flavoured version]] of the MirrorUniverse where the Imperial Planets' Starfleet wears both the Sword-and-Earth crest and the Science Police badge, and the resident {{Proud Scholar Race|Guy}} have pointy ears and arched eyebrows ''and'' green skin and blond hair. Oh, and TheEmperor of TheEmpire? [[MagnificentBastard Vandal]] ''fucking'' [[TheConstant Savage]] (Or is it an evil Flint?)!
** Asking yourself just ''how'' he became so powerful, aren't you? Answer: [[spoiler: [[CapturedSuperEntity He's got ''Q'' trapped]]]].
* ''[[Series/StarTrekTheNextGeneration The Enterprise NCC-1701-D]]'' will be getting visited by [[Series/DoctorWho a certain blue box.]] And they are going to be [[http://www.comicbookresources.com/?page=article&id=36974 fighting the Borg ''and'' Cybermen.]] [[Comicbook/StarTrekTheNextGenerationDoctorWhoAssimilation2 It's pretty awesome]].
* ''Franchise/PlanetOfTheApes'' crossed over with ''Series/AlienNation'' in one comic. The resulting title was '[[http://io9.com/5882570/the-insane-1991-alien-nation-versus-planet-of-the-apes-comic-book-nobody-remembers Ape Nation.]]'
* Phil Foglio's graphic novel adaptation of Robert Asprin's ''Another Fine Myth'' features a Law Machine from his own ''Buck Godot: Zap Gun For Hire'' universe:
-->'''Aahz''': That was our introduction to…the Law Machine. We were all dimensional travelers...I haven't seen a Law Machine before or since.
* ''ComicBook/{{Batman}}'' crossed over with ''ComicBook/{{Grendel}}'' twice, with the two crossovers featuring different Grendels. Batman is canonically one of only two people (the other being [[WolfMan Argent the Wolf]]) to be able to fight original Grendel [[VillainProtagonist Hunter Rose]] on equal terms.
* ''{{Batman}}/ComicBook/{{Hellboy}}/ComicBook/{{Starman}}'' (a two-issue DC/Dark Horse crossover) is ExactlyWhatItSaysOnTheTin.
* A very unique one concerning ''ComicBook/SpiderVerse''. Because of its TagLine of "Every Spider-Man Ever", it has the unique ability to drag in just about every possible Spidey canon, outside a few that are ScrewedByTheLawyers. One of those is the Disney/Marvel cartoon ''WesternAnimation/UltimateSpiderMan'', who has their ''own Spider-Verse'' storyline going on at the same time. It's... very confusing.
[[/folder]]

[[folder:Fan Fic]]
* [[http://alaxr274.deviantart.com/gallery/33810717 Super Milestone Wars]] and it's sequel, [[http://alaxr274.deviantart.com/gallery/36864527 Super Milestone Wars 2]]
* ''Series/BuffyTheVampireSlayer'' seems to be a bit of a crossover whore in fanfics. Crossovers include ''VideoGame/{{Halo}}, Series/{{CSI}}'', every ''Franchise/{{Batman}}'' continuity, ''Franchise/StargateVerse'', and plenty of others. A lot of the ''Halo'' crossovers are [=YAHFs=] ("Yet Another Halloween Fic", referencing the season 2 Halloween episode in which everyone got turned into their costumes) where Xander becomes John-117; these have an odd tendency to become ''Series/StargateSG1'' crossovers at the same time. There are even a couple ''{{Literature/Animorphs}}'' crossovers, despite Buffy being referenced as fictional in the Animorphs books. ''{{Series/Merlin}}'' naturally has some, due to Anthony Head playing main roles in both series.
* The online FanFilm ''WebAnimation/{{Haloid}}'', a truly impressive ''Franchise/{{Halo}}''/''Franchise/{{Metroid}}'' crossover. Technically, also a [[spoiler: ''Franchise/DeadOrAlive'']] crossover.
** The ongoing crossover series by the same author called ''WebAnimation/DeadFantasy'', consists primarily of stunt-laden over-the-top battles between characters from ''Franchise/DeadOrAlive'', ''Franchise/FinalFantasy'', ''VideoGame/NinjaGaiden'', and ''Franchise/KingdomHearts''.
* Anything by [[http://www.fanfiction.net/u/1044838/ Ten-faced Paladin]] that isn't an AlternateUniverseFic is a crossover (sadly, a couple of them are {{Dead|Fic}}).
* There is actually a rather good one between ''WesternAnimation/AvatarTheLastAirbender'' and ''Literature/HarryPotter''. [[http://forums.avatarspirit.net/index.php?topic=12814.0 here]]. He rationalizes the events as an influence for Zuko's HeelFaceTurn, and Malfoy's hesitation. And it's actually partially believable as well.
* There's a ''Franchise/SonicTheHedgehog''/''[[WesternAnimation/TheMightyDucks Mighty Ducks]]'' crossover (no, seriously) [[http://www.fanfiction.net/s/6217246/1/Sonics_Trip_to_Anaheim here]] which definitely qualifies, while also doubling as an OriginalFlavour story.
* There's a ''Franchise/HarryPotter[=/=]Film/ThePrincessBride'' [[https://www.fanfiction.net/s/135041/1/Harry-Potter-and-the-Florinese-Dream fanfic]] which features Harry as [[YouKilledMyFather Inigo]], Hermione as Buttercup, and Dumbledore as the omniscient dream narrator who breaks the [[NoFourthWall fourth wall]] repeatedly.
* The epic ''Franchise/StarWars''/''Franchise/StarTrek'' crossover fic ''[[http://www.sfdebris.com/unity.asp Unity]].'' For the record neither side really "wins," and for the whole second half the main character is the son of one ''Wars'' and one ''Trek'' character.
* [[http://www.furryconflict.com/ ''Trek Wars: The Furry Conflict'']] not only has one of the worst names in fiction, but is also one of the best and [[ScheduleSlip longest running]] Franchise/StarWars vs. Franchise/StarTrek crossovers out there, having been started in 1996 and continuing to this day. Several things set TFC apart from the rest are that (a) all the characters are [[RubberForeheadAliens furries]] with [[StarfishAliens few exceptions]], (b) [[SlidingScaleOfIdealismVersusCynicism the ST universe turned out a lot better then canon while the SW universe took a decided turn for the worse]], (c) the whole script is played out in a [[RolePlayingGame roleplay]] then transcribed to the net, and (d) none of the main characters from either franchise get more then a passing mention. In other words: it's a self-described DramaticParody that does a fairly good job of meshing the two universes, thanks to a big fat NegativeSpaceWedgie. [[http://www.furryconflict.com/galactopedia/index.php/Main_Page It even has it's own wiki]]!
* An early ''Franchise/StarTrek'' fanfic (created after Season 2) crossed over with ''Series/TheMuppetShow'' with the excuse that Doctor Bob (Rowlf) was the ship's new doctor. [[http://www.st-minutiae.com/humor/muppets.html Read the resulting hilarity here.]]
* The fanfic ''[[http://nsider.com/forums/index.php?showtopic=78378 The Chronicles of the Nine Kingdoms]]'' is essentially all the Nintendo Worlds (with a few other worlds that have appeared on Nintendo systems, like ''Dragon Warrior Monsters'') crossed over together with the ''Mario'' world as a centerpiece for a quest against evil. The author even takes it farther by planning to cross his fanfic with a ''Metroid'' fanfiction written by his friend.
* FukuFic -- ''Manga/RanmaOneHalf''-''Franchise/SailorMoon'' crossovers are so common they merit their own trope.
* ''FanFic/BothSyllables'' is a fairly well-known crossover between ''WesternAnimation/InvaderZim, WesternAnimation/BuzzLightyearOfStarCommand'', and ''WesternAnimation/LiloAndStitchTheSeries.''
* An [[http://www.netjeff.com/humor/item.cgi?file=b5vsstng.txt online fanfic crossover]] between ''Series/StarTrekTheNextGeneration'' and ''Series/BabylonFive'' contained a scene where Data tells Captain Picard that "techobabble will not work in this Universe, Captain. We are stuck with obeying the laws of Physics."
* There's been a few ''LightNovel/ZeroNoTsukaima'' stories on fanfiction.net where Louise instead summons a different familiar from another series. So far we've had [[http://www.fanfiction.net/s/3703802/1/The_Alchemist_of_Zero Edward Elric]] from ''Manga/FullmetalAlchemist'', [[http://www.fanfiction.net/s/5285567/1/Tsukaima_no_Chrono Chrono Harlaown]] from ''MagicalGirlLyricalNanoha'' and [[http://www.fanfiction.net/s/4784134/1/Zeros_Dinobot Grimlock]] from ''Franchise/TransformersGeneration1''.
** And Shirou [=EMIya=] (partial caps intentional) of VisualNovel/FateStayNight in FanFic/TheHillOfSwords.
** Also, Jack in ''[[http://www.fanfiction.net/s/6556173/1/Zeros_Shock Zero's Shock]]'' and '''ALEX FREAKING MERCER''' in ''[[http://forums.spacebattles.com/showthread.php?t=177288 Unfamiliar]]''.
* Since they are both looking for the PhilosophersStone, there are a number of fanfics where Literature/{{Harry Potter|AndThePhilosophersStone}} and [[Manga/FullmetalAlchemist Edward Elric]] meet.
* There is an obscure [[Series/TheXFiles X-Files]] and [[Series/MysteryScienceTheater3000 MST3k]] fanfic called ''[[http://web.archive.org/web/20010822075107/http://www.fortunecity.com/lavendar/pimlico/131/project.html The Project]]'' (link leads to a [[{{MST}} MST-ing]] of the fanfic). While the plot is rather generic for an X-Files fanfic, the real [[{{Narm}} charm]] of it comes from the fact that the author seems to have seen about five minutes of [=MST3k=], leading to [[{{emo}} Joel being emo]], having people [[RefugeInAudacity die from watching bad movies]] and [[spoiler:Dr. Forrester TookALevelInBadass and kills Joel]]; it's absolutely hilarious.
** A less serious take on the concept is ''[[http://web.archive.org/web/20030327090655/http://www.fortunecity.com/lavendar/pimlico/131/sol.html S.O.L.]]'', which at least has less {{OOC}} on the [=MST3K=] side (The author even mentions ''The Project'' in their note).
* ''[[{{Nasuverse}} TypeMoon]] vs. Franchise/{{Godzilla}}''. [[http://imiju.jp/Novel/GxTM00-0.htm Really]]. It's a fanfic Novel that may be in Japanese, but the [[http://www.clubdesmonstres.com/best/htm/moon_type.html art]] created for it is enough to tantalize everyone.
* ''The Doctor and the Enterprise'', a Crossover FanFic that predates the Internet, was eventually published with the ''Franchise/StarTrek'' and ''Series/DoctorWho'' serial numbers filed off.
* The ''Comicbook/SinCity'' and ''Franchise/{{Batman}}'' fanfic called FanFic/ADarkKnightOverSinCity.
* A surprising number of ''Literature/HarryPotter'' and ''Manga/YuYuHakusho'' crossovers are floating around on the Internet. The plot usually has the Yu Yu Hakusho cast infiltrate Hogwarts (with [[http://kittens-author.livejournal.com/?skip=40 The Best Defense]] probably being the best one, and likely something of a [[FollowTheLeader precursor to the rest]]).
* ''FanFic/SuikodenFantasy'', a crossover of ''VideoGame/FinalFantasyVI'' and ''VideoGame/SuikodenIII''.
* ''[[http://www.fanfiction.net/s/5076954/3/Kitsune_on_Campus Kitsune on Campus]]'' manages to place Manga/{{Naruto}} in the ''Manga/MahouSenseiNegima'' universe.
* ''[[http://smallcave.net/goferchan/afgoku01.html Goku/Anne Frank: Until the End of Time]]''. If the notion of a Dragon Ball Z/Anne Frank crossover hasn't made your brain implode already, wait until you get to the part where Hitler becomes a Super Saiyan.
* I see your Goku/Anne Frank and raise you ''[[http://www.fanfiction.net/s/991901/1/When_Wario_met_Mrs_Cartman When Wario Met Mrs. Cartman]]'', which is, well, [[ExactlyWhatItSaysontheTin about Wario meeting Cartman's mom]]. It's also a brain-melting MegaCrossover.
* [[http://www.fanfiction.net/s/899535/1/Heero_Potter_Yr_01 Heero Potter]], where [[Anime/MobileSuitGundamWing Heero Yuy]] is [[Literature/HarryPotter Harry's]] son, Duo Maxwell is Duo Weasley, Trowa Barton is Trowa Weasley, and Quatre Raberba Winner is Quatre Malfoy. I never knew the After Colony years started sometime soon after ''Literature/HarryPotter'' allegedly ended.
* Because of the popularity of a background character "Dr Hoof/Whooves", there are a swarm of crossovers between ''Series/DoctorWho'' and ''WesternAnimation/MyLittlePonyFriendshipIsMagic''. It is even the case that many fics that ''aren't'' an actual crossover will have the Doctor as a side character and more or less explicitly make clear that yes, he is the time-travelling alien beloved by fans; he just regenerated as a pony.
** In fact, due to the popularity of Friendship is Magic, and very prolific fanfic writers, My Little Pony: Friendship is Magic has crossed over with just about everything, from ''Literature/TheDresdenFiles'' to ''Series/StargateSG1''.
* ''FanFic/StarsAbove'', a crossover between ''Manga/LuckyStar'' and ''Anime/PuellaMagiMadokaMagica''.
** And by the same author, ''FanFic/{{Respect}}'', crossing over ''Madoka'' with ''Anime/SmilePrecure''.
* ''Series/BattlestarGalacticaReimagined'' and ''TabletopGame/{{Battletech}}'' crossovers have a bit of popularity due to the similarity of their FTL systems.
* [[FanFic/ConnectingTheDots "Connecting the Dots."]], an intercontinuity crossover between the Franchise/{{Justice League|OfAmerica}} and Manga/{{Naruto}}, along with a few thousand random cultural references. Think Superman fighting Naruto.
* ''[[http://www.moonie.ca/uglyduck/lnb/lbb.html#top Law and Bubbles]]'', probably the only time you'll see ''WesternAnimation/ThePowerpuffGirls'' [[JustForFun/XMeetsY meets]] ''Franchise/LawAndOrder''.
** ''[[http://z4.invisionfree.com/Refia/index.php?showtopic=1010#top Callisto Meets The Powerpuff Girls]]'' does this with ''Series/XenaWarriorPrincess''. WesternAnimation/JohnnyBravo gets a cameo.
* ''{{Series/Highlander}}'' attracts a lot of crossovers as well, mostly because there are many characters that it's easy to make immortals. ''Series/StargateSG1'' occasionally gets pulled in because of Peter Wingfield guest starring on SG-1. It also has been crossed with ''Series/BuffyTheVampireSlayer'' due to both series having groups of Watchers.
* ''{{Series/Animorphs}}'' is another series that's something of a crossover magnet because it's very easy to work in people who are controllers. It's been crossed with ''Series/{{CSI}}'', and ''Literature/MaximumRide'' is a frequent crossover because of similarities between The Flock and Tobias. ''Series/BuffyTheVampireSlayer'' and ''Series/{{Roswell}}'' were both crossed with it despite both shows being referenced as fiction in the books.
* Several arcs of ''FanFic/YouGotHaruhiRolled'' feature characters from other series interacting with the ''LightNovel/HaruhiSuzumiya'' characters. The pirate arc has, as its villains, the main characters of ''Anime/LuckyStar''. Chapter 86 has a story in which [[Franchise/{{Batman}} Batman and the Joker]] fight it out at a baseball game Haruhi attends. But it is the court case arc which goes UpToEleven, operating with the conceit that all characters from every work of fiction ever live together in a single city, thus allowing for a MegaCrossover where characters from countless fandoms take part in Haruhi's trial in one way or another.
* The FanFic/StarlightSeries attempts to seamlessly weave the ''[[WesternAnimation/LiloAndStitchTheSeries Lilo & Stitch]]'' universe with ''Franchise/StarTrek'' (in ''Starlight'' and ''Aftermath'') and ''Anime/{{Cardcaptor|Sakura}}s'' (in ''A Trip To Japan''). The former pits the gang up against ''the Borg''.
[[/folder]]

[[folder:Film]]
* ''Film/FreddyVsJason''.
* Randolph and Mortimer Duke from ''Film/TradingPlaces'' -- reduced to homeless poverty by the events of that film -- show up in ''Film/ComingToAmerica''. They fail to notice Prince Akeem's uncanny resemblance to Billy Ray Valentine.
* As a random gag in the third act of ''Film/WaynesWorld'', Wayne gets pulled over by a cop on a motorcycle… who turns out to be [[Franchise/{{Terminator}} the T-1000]], looking for John Connor. He shows up again in ''Film/LastActionHero''.
* In ''Film/{{Casper}}'', the bad guys attempt to de-haunt the house using the services of Father Guido Sarducci, and Dr. Ray Stanz from ''Film/{{Ghostbusters}}''. "Who you gonna call? Someone else!" (According to [[Wiki/{{Wikipedia}} The Other Wiki]] there was also a scene filmed with Zelda Rubenstein (Tangina Barrons from ''Film/{{Poltergeist}}'') but it was cut.)
* In ''Film/LittleNicky'', when Nicky goes to Heaven he finds [[spoiler:Chubbs, who had died in the earlier Creator/AdamSandler film ''Film/HappyGilmore'', as a dance instructor.]]
* ''Film/KingKongVsGodzilla'', in which the King of Monsters and King of Kong duke it out on Mount Fuji. It is epic.
* ''Film/GeorgeOfTheJungle'' ends with George holding George Jr. over the very same rock where Simba was similarly held. It's all Disney. And George kicked some serious lion's ass, so it could be canon.
* The comic book ''Franchise/StarWars Tales'' #19 has an alternate history story where Han and Chewie crash-land the ''Millennium Falcon'' on Earth, where it is found 126 years later by Franchise/IndianaJones. Later, Industrial Light & Magic was hired to do the effects for ''Film/StarTrekFirstContact'', and some wiseguy at ILM snuck the ''Falcon'' into the Battle of Sector 001 as a FreezeFrameBonus[=/=]EasterEgg.
[[/folder]]

[[folder:Literature]]
* The officially published ''Series/StarTrekTheOriginalSeries'' tie-in novel ''Ishmael'' by Creator/BarbaraHambly is an extended crossover with the 1968-1970 Creator/{{ABC}} series ''Series/HereComeTheBrides'', including several {{Mythology Gag}}s spanning both series and a number of {{Shout Out}}s. Additionally, it features additional crossover elements from ''Series/HaveGunWillTravel'', ''Series/DoctorWho'', ''Franchise/StarWars'', ''Series/BattlestarGalacticaClassic'', ''Series/{{Bonanza}}'', and ''Series/{{Maverick}}'', making it also a MegaCrossover.
* [[http://thatguywiththeglasses.com/videolinks/linkara/at4w/19736-star-trekx-men-1 A crossover]] introduced the crew of [[Series/StarTrekTheOriginalSeries the USS Enterprise NCC-1701]] to the Comicbook/XMen:
--->''(On encountering Gladiator in deep space)''\\
'''Kirk:''' Did he just ''punch'' my ship?\\
'''Scotty:''' Aye, Captain. And he di' damage the shields a bit.
:::And my favorite:
--->'''Nurse Chapel:''' Doctor [=McCoy=]?!\\
'''Beast and Bones:''' [[NamesTheSame Yes?]]
** [[WebVideo/AtopTheFourthWall Ladies and gentleman, the entire comic was leading up to that. That was the whole reason for this thing.]]
** There is a novel where Picard meets the X-Men ([[http://en.wikipedia.org/wiki/Planet_X_(Star_Trek) Planet X]]). It includes a rather awesome HilariousInHindsight where people point out how much [[Film/{{X-Men}} Professor X looks like Captain Picard]].
*** This is made even funnier by the realisation that the book was published over a year before ''Film/XMen1'' was filmed. There are apparently very few charismatic bald actors to go round...
* Diane Duane is a ''Series/DoctorWho'' fan, and as a result the Doctor (in different incarnations) has appeared in both her ''Literature/YoungWizards'' series and in one of her Franchise/StarTrek novels.
* Creator/NeilGaiman won a Hugo Award for ''Literature/AStudyInEmerald'', his crossover between SherlockHolmes and the Franchise/CthulhuMythos. Deservedly -- the story is ''awesome''. It can be read [[http://www.neilgaiman.com/mediafiles/exclusive/shortstories/emerald.pdf here]] for free, in nifty newsprint format. Do so now.
* The basic concept of the ''Literature/ThursdayNext'' books is that all novels are connected through the Bookworld, and Thursday can travel to them. For obvious reasons, the books Thursday enters are mostly [[PublicDomainCharacter public domain]], but the cast of Creator/EnidBlyton's ''Shadow The Sheepdog'', Beatrix Potter's Mrs Tiggywinkle and Kathy Reichs' [[Series/{{Bones}} Temperance Brennan]] have all appeared with permission. (Of the estates in the first two cases, obviously.)
* The ''Series/DoctorWho'' character Iris Wildthyme [[Characters/DoctorWhoExpandedUniverse (see here for character tropes)]] started out in a ''wildly'' unrelated series of non-genre novels. The author proceeded to use her in ''Series/{{Doctor Who|Expanded Universe}}'' novels with no change whatsoever to her character. She then got her own Creator/BigFinish spinoff and a number of appearances in the comics. Unlike with other not-quite-canon ''Doctor Who'' companions, Creator/BigFinish makes no effort to prevent a ContinuitySnarl with her, and Iris ''somehow'' being part of several different continuities all at once is considered part of her charm.
[[/folder]]

[[folder:Live Action TV]]
* The king of the intercontinuity crossover is undoubtedly Detective JustForFun/JohnMunch, played by Richard Belzer, who has appeared as of Summer 2007 on ''ten'' different programs. Originally a regular on ''Series/HomicideLifeOnTheStreet'', during the course of that series he appeared in three crossovers with ''Series/LawAndOrder''. When ''Homicide'' finished he went on to become a regular in ''Series/LawAndOrderSpecialVictimsUnit''. Not only that, but he also made guest appearances in ''Series/LawAndOrderTrialByJury'', ''The Beat'', ''Paris Enquêtes Criminelles'', ''Series/TheXFiles'', ''Series/ArrestedDevelopment'', and ''Series/SesameStreet''. And in August 2007, he filmed an episode for the fifth season of ''Series/TheWire''.
** Interestingly, there's an episode of ''Homicide'' in which Munch refers to people "watching ''The X-Files''." You could take this as a paradox, or you could figure that Munch -- a hard-core conspiracy theorist -- leaped at the chance to play himself in an ''X-Files'' episode. Which might explain why the interrogation room in that ''X-Files'' ep looked completely different from the interrogation room in ''Homicide''.
** There is uncertainty over whether Belzer appears as Munch on ''Series/TheWire''; the character was not named and received a generic billing. He mentioned that he used to own a bar, however, which he did in ''Homicide'', so there's some evidence that it was intended to be Munch.
** Taken even further with ''Series/{{Luther}}'', in which the titular character tells a subordinate to check out an American felon by sending their profiles to Munch in New York. CelebrityParadox kicks in, considering that the London cop John Luther and Baltimore gangster Stringer Bell in ''Series/TheWire'' are both played by Idris Elba.
* MTM shows did this occasionally. Carla from ''Series/{{Cheers}}'' talked about having given birth at St. Elegius, aka Series/StElsewhere, and the doctors showed up at the ''Cheers'' bar once. Sam also once directed patrons to take an ailing man to St. Elegius. Similarly, Bob from ''Series/TheBobNewhartShow'' made reference to St. Elegius, while Bob's secretary Carol showed up on ''Series/MurphyBrown'' as a temp for Murphy, thereby enfolding it into the autistic daydream which ended ''Series/StElsewhere''. See above for more information.
* The TARDIS, the LivingShip from ''Series/DoctorWho'', has appeared in the {{sitcom}}s ''Series/RedDwarf'' (set in the far future) and ''Chelmsford 123'' (set in 123 AD).
** The Doctor and Rose showed up for a panel of [[Series/BuffyTheVampireSlayer Buffy Season 8]], which means that aliens and demons may (if it's canon) exist in the same universe.
** The ''Series/DoctorWho''/''Series/EastEnders'' crossover (of very dubious quality, but it was for charity) ''Dimensions in Time'' could also be mentioned, although it's [[FakeCrossover actually not in either of the shows' continuities]] (and indeed, since then they've [[MutuallyFictional both featured each other as fictional programmes]]).
** The ''Kaldor City'' Franchise/DoctorWhoExpandedUniverse audio dramas written by Chris Boucher and produced by Magic Bullet are set in the titular city from the ''Series/DoctorWho'' story ''The Robots of Death'' (also by Boucher), but feature Scott Fredericks reprising the role of Psychostrategist Carnell from the ''Series/BlakesSeven'' story "Weapon" (also by Boucher). The ''A History'' by Lance Parkin (an un-official history of the Franchise/{{Whoniverse}}) makes a valiant attempt to claim that ''B7'' may well be set in the Whoniverse, but really it's probably best to assume he's an AlternateUniverse counterpart. Or just [[MST3KMantra don't worry about it]]. (There's also a cynical manipulator played by Paul "Avon" Darrow, who knows more about Carnell's Federation background than the Kaldorians, but let's not even get started on that...)
** Similarly, back in the heyday of Creator/MarvelComics' British arm, there were several crossovers between the Franchise/DoctorWhoExpandedUniverse (or at least the ''[[Magazine/DoctorWhoMagazine DWM]]'' comics branch of it) and the Franchise/MarvelUniverse. The first and most notable was the Special Executive, a {{Time Travel}}ling RagtagBunchOfMisfits created by Alan Moore. Originally introduced in ''DWM'' as Ancient Gallifrey's Special Ops, they later appeared in Moore's ''Captain Britain'', where they were mercenaries.
** Marvel also linked ''Doctor Who'' with ''Franchise/{{Transformers}}'', by way of bounty hunter (sorry, "freelance peacekeeping agent") Death's Head. This is a borderline case, however, as the linkage only occurred when Death's Head fell through a dimensional rift from the Marvel UK ''Franchise/{{Transformers}}'' universe and ran into the Doctor as a result.
*** In a more solid (possibly) example, the obscure character Octus has been stated to have a Dalek altmode. He was never seen transformed, but WordOfGod says that's what he turned into.
** Gallifrey itself... or rather what was left of it... shows up in the ''Series/PowerRangersLostGalaxy'' episode Green Courage with Coordinates [[http://img.photobucket.com/albums/v283/factorialinfinity/prlggallifrey.jpg to boot,]] This aired in 1999, six years before the new series, [[HarsherInHindsight by the way.]]
* It appears that the soap opera ''Series/{{Passions}}'' has set itself up as a sequel of sorts to the classic FantasticComedy ''Series/{{Bewitched}}''. It features Juliet Mills as Tabitha Lennox, a genuine witch whose daughter is named Endora and whose parents are a mortal named Darrin and a witch named Samantha. Furthermore, Bernard Fox has made two appearances on the show as his ''Bewitched'' character, Dr. Bombay.
* The ''Series/PowerRangersInSpace'' encountered the five Turtles from ''[[Series/NinjaTurtlesTheNextMutation TMNT: The Next Mutation]]''... but, uh, [[FanonDisContinuity we don't like to talk about the latter group around here]] ([[CanonDiscontinuity and neither do Eastman and Laird]]).
** On the other side of the Pacific, the world of the ''Series/SamuraiSentaiShinkenger'' had an unexpected visitor in ''Series/KamenRiderDecade''. The crossover is in continuity for both shows; in fact, the fact that the ''Shinkenger'' world is the only world in ''Decade'' that is the genuine, canonical universe of the show in question rather than an AlternateUniverse (original worlds aside) is a plot point for the arc. [[note]]Speaking of which, ''Franchise/PowerRangers'' already beat ''Franchise/SuperSentai'' at a ''Franchise/KamenRider'' crossover long ago with ''Series/MightyMorphinPowerRangers''' PoorlyDisguisedPilot for ''Series/MaskedRider''.[[/note]]
*** ''Series/{{Ultraman}} vs. Series/KamenRider'' is actually more of a team-up special than a fight with the protagonists being portrayed by {{Fake Shemp}}s, but still awesome.
*** ''Super Hero Wars: Kamen Rider vs. Super Sentai'' brings together 240 heroes across both franchises, and once again [[Series/KamenRiderDecade Decade]] is involved.
* The ''Series/{{Friends}}'' episode "The One With Two Parts" introduces Phoebe's twin sister Ursula, who was a character on ''Series/MadAboutYou''. Both had been played by Lisa Kudrow, so it was an obvious choice (to the network, at least) to make the previously unrelated characters twins. That same episode had Jamie and Fran from ''Mad'' mistake Phoebe for Ursula.
** One episode of ''Series/MadAboutYou'' itself revealed that Paul's old apartment was being loaned to Kramer from ''Series/{{Seinfeld}}''.
*** And later it was revealed that the series ''Mad About You'' exists in the ''Seinfeld'' universe. Maybe it's a reality show?
** Another ''Mad About You'' episode had Carl Reiner guest star as Alan Brady, his character from ''Series/TheDickVanDykeShow''. This created a bit of a paradox, because in an episode of ''Friends'' (which would seem to be in the same "universe") the characters are shown watching ''The Dick Van Dyke Show."
*** Not as much as you might think: The actual ''[=DvD=]'' show ended with Rob Petrie trying to find a buyer for his life story, and Alan Brady hinting that he might want to turn it into a show, which is so meta it hurts. So, it's possible that, in the fictional world where Rob, Laura, and Alan Brady live or lived alongside the ''Mad'' and ''Friends'' characters, Alan Brady eventually settled on Dick Van Dyke to play Rob Petrie -- brain exploding must stop...
** Also, Chandler briefly appeared in a ''Series/CarolineInTheCity'' episode, and Caroline briefly appeared in a ''Friends'' episode.
** Ross appeared in an episode of ''The Single Guy'', playing an old schoolmate of Jonathan's.
** Daphne and Niles of ''Series/{{Frasier}}'' were on an episode of ''Caroline In The City'', too, so that links ''Frasier'' (and, by extension, ''Series/{{Cheers}}'') into this little sitcom world, too.
*** And since ''Cheers'' linked itself to ''Series/StElsewhere'', that drags all of 1990s Must See TV into the autistic kid's dream.
** Some people FanWank [[{{Series/House}} Greg House]] into the series as the passenger that tells Rachel off on her flight to England due to neither caring about the feelings of a nearby person and both being played by Creator/HughLaurie.
* ''Series/EarlyEdition'' crossed over onto ''Series/MartialLaw''.
* ''Series/EarlyEdition'' also featured several regular characters from ''Series/ChicagoHope'' in one episode.
* ''Series/MartialLaw'' also had a crossover with ''Series/WalkerTexasRanger''. The first episode takes place on Martial Law and begins with the characters standing in their station discussing a recent crime. Then a voice rings out from off-screen, saying "I hear you could use some help." And then the camera shifts to a pair of cowboy boots and slowly pans up to reveal Ranger Cordell Walker, illuminated by a bare lightbulb overhead like some pagan godling. Then he and Sammo team up to stop violent, genocidal white supremacist militia members attempting to steal chemical weapons to use to ethnically cleanse Los Angeles. This is followed by an episode of ''Series/WalkerTexasRanger'' where Sammo visits Texas to help finish up the case. Sammo's extra-sensory and clairvoyant Chinese Daoist powers are accepted by the Rangers without a word of doubt. As Walker's long-suffering partner Trivette explains, "Around here, we call that sort of thing "Cherokee."
* ''Series/ThePretender'' had crossovers in paired episodes with ''TheProfiler,'' and the relationship between the two characters was kept in the continuity.
* Despite concepts seemingly custom-made for crossovers, ''Series/{{JAG}}'' and ''Series/{{NCIS}}'' only crossed over for one two-parter. Though NCIS didn't exist as a separate show when the crossover happened. In other words, a PoorlyDisguisedPilot.
** ''JAG'''s Lt. Bud Roberts did appear in the first season ''NCIS'' episode ''Hung Out to Dry''.
** Meanwhile, Lt. Cmdr. Faith Coleman and a Navy SEAL played by Adam Baldwin appeared on both series.
* It's not quite ''Archie Meets The Punisher'' bizarre, but the special ''Alice'' two-parter that featured a visit from Boss Hogg, Roscoe and Enos from ''Series/TheDukesOfHazzard'' (Boss Hogg was [[strike:Not-Flo]] Joleene's cousin) is up there.
* ITV drama series ''Footballers' Wives'' briefly exported popular character Tanya Turner to ''Bad Girls'' (also produced by ITV) when Tanya was jailed during the plot.
* The creators of ''Series/{{Lost}}'' and ''Series/{{Heroes}}'' have discussed the possibility of intertwining their shows, but are largely unable to do so because they are on different networks. However, small details have crossed over. Characters on both shows have sported identical brochures for the fictitious Gannon Car Rentals.
** ''Lost'' has also featured a few shoutouts to ''Series/{{Alias}}'', though it's unlikely they exist in the same universe due to Terry O'Quinn's characters in both shows being completely unrelated.
*** Actually, they '''do''' exist in the same universe, as a CIA agent is shown listening to one-hit wonder''Drive Shaft'', "You All Everybody", on his workstation. Ergo, Charlie Pace (played by Dominic Monaghan) is part of the Aliasverse, meaning LOST is part of it as well.
*** Likewise, an Oceanic Airlines flight to Sydney was mentioned in passing on ''Alias''.
*** An Oceanic Airlines ad also appeared during the pilot episode of ''{{Flash Forward|2009}}''.
*** [[Series/{{Lost}} The disappearance of Oceanic Flight 815]] was mentioned in passing on ''Series/{{Fringe}}''.
*** This could be because Oceanic Airlines is a generic name that a lot of shows use. [[Wiki/{{Wikipedia}} The Other Wiki]] has [[http://en.wikipedia.org/wiki/Oceanic_Airlines details]].
** Also, the [[spoiler:big "cork" on the bottle of evil]] at the end of the show pretty closely resembles [[spoiler:a [[Series/BuffyTheVampireSlayer Hellmouth]].]] Probably not intentional, but wouldn't it explain ''everything''?
* Speaking of ''Series/{{Lost}}'', one of Chef Robert Irvine's missions on ''Series/DinnerImpossible'' was to cook for the cast of ''Series/{{Lost}}''. Though it was clear to everyone that ''Series/{{Lost}}'' is only a television show, Nestor Carbonell did appear in character as Richard Alpert and Robert was given several Dharma food drops to work with, so it qualifies somewhat for this trope.
* In an episode of ''Series/{{Reba}}'' involving a court, the judge is obviously intended to be Philip Banks from ''Series/TheFreshPrinceOfBelAir,'' and is played by the same actor, despite ''Reba'' taking place in Houston and ''Fresh Prince'' taking place in California.
* ''Series/CrossingJordan'' and ''Series/LasVegas'' crossed over so often that it probably doesn't even qualify as intercontinuity crossover. They certainly take place far enough apart geographically that it's plausible that they're within the same continuity. I think that the ''Series/CrossingJordan'' characters made one more appearance in ''Series/LasVegas'' after their own show had been canceled, though both shows are now finished.
** In one LV episode, Mary made a reference to booking a conference room for [[TheOffice Dunder-Mifflin]], and ''Series/{{Heroes}}'' and the 2008 ''Series/KnightRider'' series have both made references. Linderman being involved would certainly explain the Montecito's high owner turnover rate. Don't combine it with the ''Series/{{Lost}}'' bit above, though, or your head might explode.
* When a mentally ill patient filed a paternity suit against Dr. Kiley on ''Marcus Welby, M.D.'', the trial was resolved by ''Owen Marshall: Counselor at Law''.
* ''Series/PicketFences'' crossed over into ''Series/ChicagoHope'' (both shows created/executive produced/written by David E. Kelly and airing on CBS), when Fyvish Finkel's character Douglas Wambaugh checked into the hospital. They also poked at ''Series/{{ER}}'' featuring a "commercial" for the hospital that parodied the opening credits of ''ER'' and later having one character say, "We don't like to talk about that ''other'' hospital."
* Because both series were produced by William Dozier, it was practically foreordained that Franchise/TheGreenHornet and Kato would make an appearance in ''Series/{{Batman}}'', which they did in the episodes "A Piece of the Action"/"Batman's Satisfaction", which aired on March 1 and 2, 1967, as well as an appearance in a brief "window gag" in another episode. The styles of the two shows didn't really mesh, however.
** As for the styles of the shows not meshing, in the Hornet's "window gag" appearance (the earlier of the two appearances), Batman and Robin acknowledge his and Kato's status as heroes. In the later guest appearance, the episodes run with the standard "on police records a wanted criminal" plot device of the ''Green Hornet'' property, and entangle the Hornet/Kato and Batman/Robin in a LetsYouAndHimFight standoff.
** Later episodes would have Batman and Robin meet Colonel Klink from ''Series/HogansHeroes'' or Lurch from ''Series/TheAddamsFamily.'' in the window gag.
* Creator/USANetwork does this on a regular basis in their ads. If you take, say, [[http://www.youtube.com/watch?v=R8oW0wBWlog "Monk: A Tribute"]] as canon, ''Series/{{Monk}}, Series/{{Psych}}, Series/RoyalPains, Series/LawAndOrderCriminalIntent, Series/InPlainSight,'' and ''Series/BurnNotice'' all take place in one universe. Sooner or later, all of their major series end up there.
* Creator/{{Disney|Channel}} took this to an extreme, theming two entire episodes specifically for the crossover: ''[[Series/ThatsSoRaven That's So]] [[Series/TheSuiteLifeOfZackAndCody Suite Life of]] Series/HannahMontana'' and ''Series/{{Wizards|OfWaverlyPlace}} [[TheSuiteLifeOnDeck On Deck with]] Series/HannahMontana''.
* The Series/{{Mythbusters}} appear in an episode of the original ''Series/{{CSI}}'' (Vegas). From the way the segment is filmed its unclear whether they are intended to be fictional lab-techs, "themselves" visiting the lab, or a figment of Nick's imagination. However they later tested the same theory on Mythbusters, using clips from the CSI episode.
** Speaking of ''CSI'', that show once shared a rather odd crossover with the sitcom (and fellow CBS hit series) ''Series/TwoAndAHalfMen''.
** The franchise also crossed over with ''Series/ColdCase'' and ''Series/WithoutATrace'' one time each. Some consider those two plus the three CSI series to be one big 'verse.
* ''Series/{{Fringe}}'' has a particularly interesting example of this trope. The Observer, or rather [[spoiler: one of them, specifically September]], whose task it is to police inter-dimensional travel and interferences with the timeline, has managed to crossover from the ''Fringe'' continuity... into the "real world". He appeared in the audience of ''Series/AmericanIdol'' and has been spotted in various stadiums during Fox sports broadcasts.
** It's unclear whether the fact that Fringe Division's job used to be called [[Series/TheXFiles the "X-Designation"]] is this or a ShoutOut.
* This one's a little older, but in an episode of ''Radio/TheJackBennyProgram'', Jack goes to court for supposedly murdering a rooster he owns. Who does he get as his lawyer? Franchise/PerryMason. Although it may not count officially, since it was AllJustADream on Jack's part. Oh, and the true murderer? [[spoiler: Perry Mason himself]].
* An episode of ''Series/{{Warehouse 13}}'' included [[ButtMonkey Douglas Fargo]] of ''Series/{{Eureka}}''. An episode of ''Eureka'' included Claudia Donovan from ''Warehouse 13''. This is an example of a SharedUniverse, as both shows (as well as Series/{{Alphas}}) are part of the "[[Creator/SciFiChannel SyFy]] Verse".
* Creator/RLeeErmey turned up in Season 1 Episode 4 of ''Series/PawnStars'' in full ''Lock n' Load'' gear.
* ''Series/AllyMcBeal'' and ''Series/ThePractice'' had a two-part crossover special that started on ''Series/AllyMcBeal'' on Fox and was resolved in the next hour on ''Series/ThePractice'' on ABC, with several characters from each show appearing on the other show. Both shows were produced by David E. Kelley.
* [[Series/{{ER}} Susan's]] niece was missing when her sister Chloe overdosed, and was found by [[Series/ThirdWatch the police in New York]].
* UsefulNotes/ComicRelief frequently features entirely non-canonical intercontinuity crossovers. Notable ones include:
** 1997's ''{{Prime|Suspect}} {{Cracker}}'', in which Fitz and DCI Tennyson hook up and decide that now they have a relationship they don't ''care'' who the killer is.
** 1997 also had ''Series/{{Ballykiss|angel}}[[Series/TheVicarOfDibley Dibley]]'', in which Geraldine desperately tried to convince a visiting Father Peter that her parishioners were normal.
** 2009's ''When Janet Met Michelle'', which combined all BBC Three's sitcoms about twentysomethings, as the cast of ''Series/TwoPintsOfLagerAndAPacketOfCrisps'' invited characters from ''Grownups'' and ''Coming of Age'' to their fundraiser party. The title refers to the characters played by Sheridan Smith in ''Two Pints'' and ''Grownups'', who [[ActingForTwo did indeed meet]].
** One between ''Series/TheCatherineTateShow'' and ''Series/DoctorWho'' (with a bit of RecursiveCanon).
** In 2013, a skit with the 1950s midwives from ''Series/CallTheMidwife'' inexplicably in [[FishOutOfTemporalWater a modern maternity ward]] got even more bizarre when the increasingly exasperated father called for a doctor, and the TARDIS materialised.
* Similarly, 2010's ChildrenInNeed telethon included ''Series/{{East|Enders}} [[Series/CoronationStreet Street]]'', in which a bunch of characters from each soap arrive at the location of the other one, including Gail Platt and Denise Johnson competing to see who has the most tragic backstory. The cliffhanger ending was that Liz Macdonald is [[LukeIAmYourFather Kat Moon's mother]], in a direct parody of the revelation that Kat is Zoe's mother. See also the ''Series/DoctorWho'' entry above for an earlier ChildrenInNeed '''Stenders'' crossover.
* Creator/BryanFuller likes to do this. Marianne Marie Beetle was a tenant of Jaye's trailer park in ''Series/{{Wonderfalls}}'', and then showed up at a competition in ''Series/PushingDaisies'', despite the fact that Jaye's brother in ''Wonderfalls'' plays the main character, Ned, in ''Pushing Daisies'', so they exist in the same universe, technically. And Jaye's mother is also Mother Superior in the second season of ''Pushing Daisies''.
** And Ned mentions the Happy Time Temp Agency by name, so ''Pushing Daisies'' and ''Series/DeadLikeMe'' exist in the same universe as ''Wonderfalls'', which makes the CelebrityParadox even more fun, because Jewel Staite plays a to-be-reaped record store employee in ''Dead Like Me'', and then later played Jay's boyfriend's ex-wife in ''Wonderfalls''.
** Now ''Series/{{Hannibal}}'' is part of the continuity. Gretchen Speck (she dropped the Horowitz in the divorce, apparently), from Wonderfalls, is in Hannibal, and played by the same actress. (And in Creator/BryanFuller fashion, CelebrityParadox kicks in, because Caroline Dhavernas is in both.)
* The NickVerse includes several Creator/DanSchneider productions like ''Series/{{Zoey 101}}'', ''Series/ICarly'', ''Series/{{Victorious}}'', ''Series/SamAndCat'' and ''Series/DrakeAndJosh'' as the core of the SharedUniverse. However:
** It ''also'' includes SketchComedy shows ''Series/AllThat'' and ''Series/TheAmandaShow''.
** It '''also''' includes ''Series/YoGabbaGabba'' which had crossovers with ''Series/BigTimeRush'' and ''Series/TrueJacksonVP''.
** Carlton Banks from ''Series/TheFreshPrinceOfBelAir'' shows up in an episode of ''Series/BigTimeRush'', which puts the entire NickVerse into the Series/StElsewhere "It Was All A Dream" continuity.
* Niecy and Hakeem from ''{{Moesha}}'' appeared together in an episode of ''{{Series/Clueless}}'' after UPN picked up that series.
** This became a trend when Niecy appeared on ''{{Series/Girlfriends}}'' and Maya appeared on ''Moesha'' as the aunt of Dorian's stepsiblings.
*** The character Peaches from ''Girlfriends'' made an appearance on ''{{Series/Eve}}''. Taking all the connecting shows into account, Brandy has masqueraded as no less than '''four people''' in the UPN-verse: Moesha, [[CelebrityParadox herself]], Chardonnay (''Series/TheGame'', spinoff of ''Girlfriends''), and a mystery caller on ''Sabrina, the Teenage Witch'' (which crossed over with ''Clueless'').
* ''Series/{{Angel}}'': Illyria appeared in ''FallenAngel: Reborn''.
[[/folder]]

[[folder:Pinball]]
* ''Pinball/ThePartyZone'' is this for the various "party" pinball games by Creator/DennisNordman -- it crosses over characters from ''Party Animal,'' ''Pinball/ElviraAndThePartyMonsters,'' and ''Pinball/DrDude''.
[[/folder]]

[[folder:Professional Wrestling]]
* Wrestling/NewJapanProWrestling has Jushin Liger, Tiger Mask, and Black Tiger, all of whom were anime characters before NJPW licensed their likenesses and created wrestlers out of them. It makes sense for Tiger Mask and Black Tiger, as the anime they originate from was about wrestling in the first place, but Jushin Liger was created for a {{Henshin}} series that takes place TwentyMinutesIntoTheFuture about a holy warrior with the power of the liger (half-lion, half-tiger) who battles evil aliens bent on destroying the world. Makes sense.
* When Wrestling/HulkHogan's first movie, ''Film/NoHoldsBarred'', hit theaters, the Wrestling/{{WW|E}}F thought it'd be a good idea to bring in the villain of the film, [[http://www.thewrestlinglegendsforum.com/wrestlecrap/zeus.html Zeus]], to battle Hulk in a WWF ring. They were never really clear on whether this was supposed to be the movie character come to life, or the actor assuming the character's persona to wreak havoc (in some promos, he'd lean one way, in others, the other), but one thing was absolutely clear throughout the entire angle: it was Website/WrestleCrap.
* Franchise/RoboCop (yes, [=RoboCop=]!) appeared at Wrestling/{{WCW}}'s ''Capital Combat 1990'' to rescue Wrestling/{{Sting}} from a cage he was placed in by the Four Horsemen.
* Chucky (the CreepyDoll from ''Film/ChildsPlay'') [[http://www.youtube.com/watch?v=CbXR21Esjq4 interrupted a Rick Steiner promo]]. Sadly, he didn't take up Rick's challenge to meet him in the ring.
[[/folder]]

[[folder:Tabletop RPG]]
* ''TabletopGame/{{Spelljammer}}'' [[http://sjml.spelljammer.org/archive/oracle/200008/01-000009.html fan campaign]]: Second Unhuman War [[BeethovenWasAnAlienSpy as an extension]] of the [[TabletopGame/{{Planescape}} Blood War]] -- that is, between Elves corrupted and manipulated by [[ChaoticEvil Tanar'ri]] and [[OurOrcsAreDifferent Scro]] corrupted (if they need more) and manipulated by [[LawfulEvil Baatezu]].
* ''Die, Vecna, Die'' was an intercontinuity adventure module, intertwining events in TabletopGame/{{Greyhawk}}, TabletopGame/{{Ravenloft}}, and TabletopGame/{{Planescape}}.
** Planescape, along with TabletopGame/{{Spelljammer}} had partly come to be to facilitate crossovers by connecting the various campaign settings -- or, to put it another way, to render ''Die, Vecna, Die'' style campaign-setting crossovers into ordinary crossovers. On the other hand, Ravenloft was supposed to have a rather one-way connection to the rest of the multiverse (things could enter, but they couldn't leave), so something ''coming out'' of Ravenloft to have a crossover ''was'' rather unexpected...
* ''TabletopGame/{{Paranoia}}'' had one of these with ''Cyberpunk'' in 1989 with the adventure ''Alice Through the Mirrorshades''. In true ''Paranoia'' fashion, every aspect of ''Cyberpunk'' was given a thorough mocking, from its gritty near-future setting to it's "style over substance" ethos to creator Mike Pondsmith himself.
* Phil Masters's ''TabletopGame/MageTheAscension'' setting ''[[http://www.philm.demon.co.uk/RPGs/MageMysterons.html Mage 2069: No Strings Attached]]'', in which the Traditions destroyed The Computer and took control of the internet in 2025, and the Technocracy responded by downplaying the very idea of computers from the Consensus. By 2069 the Technocracy has won ... only the Void Engineers are still finding Umbrood in [[Series/FireballXL5 near space]] and [[Series/{{Stingray 1964}} the oceans]]. And the remains of the Sons of Ether keep creating mega-projects that [[GoneHorriblyWrong Go Horribly Wrong]], requiring [[Series/{{Thunderbirds}} an international rescue team]] of Iteration X agents to sort things out. And then there turns out to be ''something'' completely inimicable to the Consensus on Mars. So the NWO - having long abandoned the [[TheMenInBlack M.I.B.]] look - send their [[Series/CaptainScarletAndTheMysterons brightly-uniformed agents from a flying base]] to investigate. Astral Is Green...
* On a not-very-similar note, ''Pyramid'' magazine once described a ''TabletopGame/MageTheAscension'' scenario where a bunch of mages start using vulgar magic in the wake of a space station exploding, the Technomancy leaps on the "scientific" explanation secretly fed to them by the Traditions without noticing it opens cracks in the Consensus that would allow Sleepers to start manifesting "superpowers", and the next thing anyone knows, it's the ''TabletopGame/{{Aberrant}}'' universe.
[[/folder]]

[[folder:Theme Parks]]
* Several examples in the Ride/DisneyThemeParks. The biggest example is ''Theatre/{{Fantasmic}}'', where a LegionOfDoom of Disney Villains [[BattleInTheCenterOfTheMind invade Mickey's mind]].
** ''Ride/TheGreatMovieRide'' has both [[Film/TheGoodTheBadAndTheUgly The Man With No Name]] and [[Film/TheSearchers Ethan Edwards]] together in one scene.
[[/folder]]

[[folder:Toys]]
* Matt Trakker of ''WesternAnimation/{{MASK}}'' re-emerged as an action figure in the ''Franchise/GIJoe'' line, presumably because Creator/{{Kenner}} (''WesternAnimation/{{MASK}}''[='s=] manufacturer) merged with Creator/{{Hasbro}} (''Franchise/GIJoe''[='s=] manufacturer) years ago.
** [[{{Squee}} SQUUEEEEEEEEEE--]] Oh, excuse me!
** G.I.Joe's original intercontinuity crossover character, Wrestling/{{WW|E}}F wrestler Wrestling/SgtSlaughter.
** Hasbro has also done ''G.I. Joe'' action figures for Franchise/{{Rocky}} Balboa and William "The Refrigerator" Perry as team trainers.
** And also ''G.I. Joe'' action figures for ''VideoGame/StreetFighterII''. In fact, it was there when Ken got his last name, Masters, because they couldn't name an action figure "Ken" thanks to ''Franchise/{{Barbie}}''.
* For a few years, Hasbro had a ''Franchise/{{Transformers}}'' sub-line called Transformers Crossovers, including ''Franchise/StarWars'' and Creator/MarvelComics characters. They are presented as the characters driving vehicles that transform into HumongousMecha that look like they do, ranging from a [[Comicbook/IncredibleHulk Hulkbot]] turning into a tank to a moon-sized Darth Vader robot transforming to the Death Star. The ''Star Wars'' ones have an advantage in that they can use existing vehicles to turn into. The Marvel ones ''don't'' have existing vehicles (for the most part... but then again, try remembering the last time you saw Spider-Man's Spider-Mobile), but this is an advantage in its own way as they can be designed almost entirely around making the robot mode look right.
** There's also the Disney Label ones, including "{{Mickey|Mouse}} Prime" and a Bumblebee WesternAnimation/DonaldDuck. Doesn't seem like these Disney crossovers will be coming to the US, though.
[[/folder]]

[[folder:Video Games]]
* ''VideoGame/GarrysMod'' allows you to do all kinds of crossovers with the right mods. Want [[VideoGame/{{Halo}} John-117]] to team up with [[VideoGame/HalfLife Gordon Freeman]] and fight [[Franchise/MassEffect Saren]]? Have fun.
* ''VideoGame/MarioAndSonicAtTheOlympicGames'' featured the first meeting of [[Franchise/SuperMarioBros Mario]] and Franchise/SonicTheHedgehog. Since the pair were the mascots of former [[ConsoleWars warring console makers]] Creator/{{Nintendo}} and Creator/{{Sega}} (respectively), [[CueTheFlyingPigs this was something of a big deal for old-school gamers.]]
* ''VideoGame/SuperSmashBros'' which features ''all'' of the first- and second-party Nintendo characters meeting (though technically it's not them, they're just Gashapon figurines brought to life). From Mario, to Link, to the Pokemon. And now there's the ones not from Nintendo, such as {{Franchise/Sonic|TheHedgehog}} and [[Franchise/MetalGear Snake]]. [[http://www.youtube.com/watch?v=mME569si9hY Also]] VideoGame/{{Mega Man|Classic}} [[https://www.youtube.com/watch?v=dVz-2VuAYlY and]] VideoGame/PacMan.
* ''Mario Hoops 3-on-3'' and ''VideoGame/MarioSportsMix'' add ''Franchise/FinalFantasy'' characters to the traditional cast of Mario sports games.
* The ''[[VideoGame/ItadakiStreet Fortune Street]]'' series eventually added ''VideoGame/DragonQuest'' characters to the game. Sony installments of the series crossed them over with ''Franchise/FinalFantasy'' characters, while the Wii and DS installments mixed them up with the ''Franchise/SuperMarioBros'' cast.
* Two games by ''Shounen Jump'' were made that put up some of their high-end mascots up against each other in the same vein as ''Super Smash Bros.'' The most popular and most varied is the ''JumpSuperStars'' game on the Nintendo DS. On the Gamecube, focusing on its most successful series, is ''Battle Stadium DON'', with DON being an acronym for ''Manga/DragonBall'', ''Manga/OnePiece'', and ''Manga/{{Naruto}}''.
* ''VideoGame/{{Wario|Land}} Blast: Featuring VideoGame/{{Bomberman}}!'' which is what the title says. (Except in Japan, where it was ''GB Bomberman'' and had nothing to do with Wario.)
** The ending of ''VideoGame/{{Bomberman}}'' for the NES had Bomberman turning into the player character from Creator/HudsonSoft's NES version of ''VideoGame/LodeRunner''.
* The Gilliam Yaeger who is the final boss of the Super Famicom game ''Hero Senki'', and who appears in the ''VideoGame/SuperRobotWars'' initial continuity, and the ''Original Generation'' continuity are all the same character.
** For that matters, the ''VideoGame/SuperRobotWars'' series itself is ''built'' on the idea of Anime/MazingerZ and Shinji Ikari teaming up to beat up Char Aznable.
** Also notable in ''Super Robot Wars OG Saga: VideoGame/EndlessFrontier'', Reji and Xiaomu from ''VideoGame/NamcoXCapcom'' confirm that KOS-MOS from ''VideoGame/{{Xenosaga}}'' comes from their future (which was already established in the former's game).
* ''VideoGame/MortalKombatVsDCUniverse''. And in ''VideoGame/MortalKombat9'' DLC, vs [[Franchise/ANightmareOnElmStreet Freddy Krueger]]. The {{P|layStation3}}S3 version had Kratos from ''VideoGame/GodOfWar'' as a GuestFighter.
* Though it's technically one series, each of the ''Franchise/FinalFantasy'' games has [[NonLinearSequel its own world and continuity]], which means Gilgamesh's appearances in various games (it's hinted he's the same character, moving through the alternate universes) count.
** And then there's ''VideoGame/FinalFantasyTactics'', where you can send out other characters on jobs, and they may return having found the BigBad's palace from ''VideoGame/FinalFantasyII,'' or the phantom train from ''VideoGame/FinalFantasyVI,'' or the fake Excalibur from ''VideoGame/FinalFantasyV''.
*** The sidequest to get Cloud in your party. The PSP port of ''Tactics'' also included Balthier from ''VideoGame/FinalFantasyXII'' and Luso from ''VideoGame/FinalFantasyTacticsA2''. In the case of Cloud too, it's suggested that his stint in Ivalice occurs when he fell into the lifestream, hinting that it's the actual Cloud from ''VideoGame/FinalFantasyVII''. Less so with Balthier and Luso, who are more or less there with no explanation. Lampshaded by Balthier himself even, who mentions that his role in the game... "feels more like a cameo role".
* DJ Atomica, the (some would say) [[DumbassDJ annoying announcer]] in ''VideoGame/{{Burnout}} Paradise,'' is the same guy who provided the commentary for ''SSX 3''. In ''Paradise,'' he makes reference to ''SSX'' several times, suggesting it's supposed to be the same character.
* A couple of recent ''[[Anime/YesPrettyCure5 Yes! Pretty Cure 5GoGo!]]'' video games have incorporated characters from the [[Anime/FutariWaPrettyCure previous]] [[Anime/FutariWaPrettyCureSplashStar universes]]. The story implications of the ''[[VideoGame/TheIdolmaster iDOLM@STER]]'' knockoff are probably not significant, but the DS game has a plot suggesting they all share a universe and simply never ran into each other before (which does happen in the ''Anime/PrettyCure All Stars DX'' movie).
*** Some ''VideoGame/AceCombat'' forum goers have taken the existence of ''[=iDOLM@STER=]'' skins in DLC to suggest that those characters are animated versions of actual musical artists in Strangereal.
* ''Super Puzzle Fighter II Turbo'' has characters from ''Franchise/StreetFighter'', ''VideoGame/{{Darkstalkers}}'', and ''VideoGame/{{Cyberbots}}''. There's only one character from the latter, though.
* Creator/{{Capcom}}'s [[VideoGame/CapcomVsWhatever "Vs. series"]] started life as such with ''VideoGame/XMenVsStreetFighter'' and ''VideoGame/MarvelSuperHeroesVsStreetFighter'' before stepping into MassiveMultiplayerCrossover territory; it hasn't looked back since.
** Capcom does a lot of crossovers. ''VideoGame/MegaManBattleNetwork'' with ''VideoGame/{{Boktai}}''. ''VideoGame/MetalGearSolidPeaceWalker'' with ''VideoGame/MonsterHunter''. And now... ''VideoGame/ProfessorLaytonVsAceAttorney''.
* ''VideoGame/ShinMegamiTenseiIIINocturne'' features a guest appearance by Dante from ''Franchise/DevilMayCry''. In exchange for this being done, series demon artist Kazuma Kaneko designed the Devil Trigger forms of the Sons of Sparda in ''Devil May Cry 3''.
* One of the boons from finishing an ''VideoGame/EscapeVelocity: Nova'' storyline is access to one of two known (very expensive) ships "found floating near a wormhole at the farthest end of known space". Scientists "theorize that these mystery ships somehow entered our galaxy from a parallel dimension." The ship is from the original ''Escape Velocity'' game, which has practically identical (albeit less developed) gameplay but a completely different universe.
* One of the earliest intercompany video game crossovers was ''Battletoads & Double Dragon: The Ultimate Team'', a crossover between Creator/{{Rare}}'s ''VideoGame/{{Battletoads}}'' and Technos Japan's ''VideoGame/DoubleDragon'' franchises ([[ExactlyWhatItSaysOnTheTin natch]]) released in 1993 for various platforms. This was made possible by the fact that Tradewest published both series in America and Europe, although the game itself was really more of a ''Battletoads'' game with ''Double Dragon'' characters as guest stars ( some which were misnamed in the game).
* ''Franchise/KingdomHearts'' is a crossover between Creator/{{Disney}} and ''Franchise/FinalFantasy''.
** "Disney" seems a bit unspecific, but that's because it's pretty much ''everything Disney owns.''
** As of ''Dream Drop Distance'', characters from ''VideoGame/TheWorldEndsWithYou'' are showing up, so now it's "anything Disney and potentially anything Square-Enix owns".
* ''VideoGame/MyWorldMyWay'' features two characters, the mysterious dungeon diggers Owen and Kate, who were the protagonists of a previous {{Atlus}}/Global A game entitled ''Master of the Monster Lair''. Owen even carries around the magic shovel that he had in ''Monster Lair'', and the dungeon layouts are similar in both games.
* So far, [[Franchise/TheLegendOfZelda Link]], [[VideoGame/{{Tekken}} Heihachi]], Comicbook/{{Spawn}}, [[VideoGame/GodOfWar Kratos]], [[Franchise/AssassinsCreed Ezio Auditore]], [[Franchise/StarWars Darth Vader and Yoda]], and [[VideoGame/TheForceUnleashed Starkiller]] have all appeared in the VideoGame/SoulSeries.
* ''VideoGame/PokerNightAtTheInventory'' features Tycho Brahe, Max, Heavy Weapons Guy, and Strong Bad, from ''Webcomic/PennyArcade'', ''VideoGame/SamAndMaxFreelancePolice'', ''VideoGame/TeamFortress2'', and ''WebAnimation/HomestarRunner'', respectively, all playing poker together, plus an assortment of characters milling around the background.
** [[VideoGame/PokerNight2 The sequel]] continues this, crossing ''VideoGame/SamAndMaxFreelancePolice'' again (Sam this time), ''WesternAnimation/TheVentureBrothers'' (Brock Samson), ''[[Franchise/EvilDead Army of Darkness]]'' (Ash), ''VideoGame/{{Borderlands}}'' (Claptrap), and ''VideoGame/{{Portal}}'' ([=GLaDOS=]).
* Although it's all from the same company, this schtick is a favorite of Creator/NipponIchi. Characters tend to show up in each other's games with reckless abandon, ranging from minor cameos to secret characters to actual plot-relevance. Laharl ends up in a bottle in ''VideoGame/PhantomBrave'' and chews out Revya in ''VideoGame/SoulNomadAndTheWorldEaters'' for trying to take his title. Etna is a central secondary character in ''{{VideoGame/Disgaea 2|CursedMemories}}''. Lujei (from ''VideoGame/GrimGrimoire'') is responsible for Endorph (who is really [[spoiler:Walnut from ''Phantom Brave'']]) appearing in ''Soul Nomad''. Everyone of any importance shows up in ''{{VideoGame/Disgaea 3|AbsenceOfJustice}}'' as downloadable content. And to top it off, you have Asagi, the wandering protagonist without a game of her own, trying to usurp the hero role in almost every game.
* Interesting crossover here, in ''Franchise/DevilMayCry''. Dante receives the sword named Alastor, imbued with an electrical motif. Later on in ''VideoGame/ViewtifulJoe'', a character named Alastor appears, complete with the electrical motif. The connection is later made in the [[PlayStation2 PS2]] port of ''Viewtiful Joe'' in which Dante guest stars and Alastor (revealed to be the spirit of Dante's sword) harbors some unfriendly feelings towards Dante (for leaving him behind in ''Devil May Cry 2'').
** After this, the connection is pushed forward in ''VideoGame/TatsunokoVsCapcom'' in which Morrigan's win quote vs. Viewtiful Joe mentions that she was disappointed in him after talking to Alastor. Leading to an implication that ''VideoGame/{{Darkstalkers}}, Devil May Cry'', and ''Viewtiful Joe'' are all part of the same universe.
** Done again in ''VideoGame/MarvelVsCapcom3'', where Dante and Joe's unique intro quotes for each other show the two to be friendly acquaintances. This would be odd, as Dante never actually ran into Joe in his ''Viewtiful Joe'' story, but he ''was'' playable in the [=PSP=] version of ''Viewtiful Joe: Red Hot Rumble''.
** ''VideoGame/{{Bayonetta}}'', another Creator/ShinjiMikami creation, drops ''numerous'' hints that it exists in the same world as ''Devil May Cry''. This is particularly done through the use of Enzo, who has the same name and personality traits of an information broker who was pals with Dante and mentioned as early as the instruction manual for ''Devil May Cry'', but the lore for one of the unlockable accessories, the [[TimeStandsStill Bracelet of Time]] (which is visually similar and functionally identical to the Bangle of Time from ''[=DMC1=]'' [[note]]with a small remainder of the design borrowed from the V-Watch in ''Viewtiful Joe''[[/note]]), notes that it was created by Eva (Dante's MissingMom), "a truly extraordinary [Umbra] witch" who "entered into contract with a legendary dark knight" (i.e. her husband Sparda). Additionally, Luka's father is a world-famous journalist well versed in the supernatural who goes by the name Antonio Redgrave. Dante's preferred alias in the ''[=DMC1=]'' novel and ''[[Anime/DevilMayCryTheAnimatedSeries The Animated Series]]''? Tony Redgrave. When asked about the connection, Kamiya answered on his Twitter account that Dante respected Antonio and his work, so took the name during his early days as a demon hunter. Luka also name drops [[VideoGame/ResidentEvil2 Claire]], [[Franchise/DevilMayCry Trish]], [[VideoGame/ViewtifulJoe Silvia]], and [[VideoGame/{{Okami}} Ammy]] as girls he's dated in the past, but that's presumably [[ShoutOut a fun little nod to Kamiya's past works]].
* Free Flash game crossover: In ''VideoGame/{{Shift}} 3'' you can unlock [[VideoGame/FancyPantsAdventures Fancy Pants Man]] as a SecretCharacter.
* ''VideoGame/MetalGearSolid3SnakeEater'' featured a bonus minigame where Solid Snake is assigned capture a bunch of escaped monkeys from the ''VideoGame/ApeEscape'' series. In turn, ''VideoGame/ApeEscape 3'' featured a bonus mini-game where the player controls a monkey named Pipo Snake who must rescue Solid Snake.
* Via "Fall of the Space Core, Volume 1", a mod collaboration for ''VideoGame/TheElderScrollsVSkyrim'' between Creator/{{Valve|Software}} and Creator/{{Bethesda}}, the Space Core from ''VideoGame/{{Portal 2}}'' crash-lands near Whiterun and gets picked up by the Dovahkiin. No word on where [[spoiler:Wheatley]] ended up.
** Or as Valve put it, a patch to put NolanNorth in Skyrim.
* ''VideoGame/PokemonConquest'' is this. It's ''Franchise/{{Pokemon}}'' combined with the ''VideoGame/NobunagasAmbition'' franchise.
* ''VideoGame/CallOfDutyBlackOps2'' and ''Manga/{{Jormungand}}''.
* ''Franchise/ShinMegamiTensei'' and ''Franchise/FireEmblem'' have a crossover game planned for the WiiU.
* ''VideoGame/RealityOnTheNorm'', a SharedUniverse RoundRobin series, has had some games about character from other games entering the city of Reality, such as VideoGame/CommanderKeen or Monty Mole. Then there's ''Shadows of RON'', whose developer actually included the character from his own book series as the protagonist.
* More interesting hints at Capcom's [=IPs=] [[SharedUniverse existing in the same universe]]: in the first ''VideoGame/DinoCrisis'', certain crates can been seen sporting the [[Franchise/ResidentEvil Umbrella Corporation]] logo. The game's setting (the Borginian Republic) in reused in the ''Franchise/AceAttorney'' series (as the Republic of Borginia). And speaking of ''Resident Evil'', many ''[[VideoGame/ResidentEvil4 RE4]]'' players remember a dog in a bear trap encountered early in the game that, [[PetTheDog if]] [[VideoGameCaringPotential rescued]], [[AndroclesLion will come to]] [[BigDamnHeroes your aid]] during the El Gigante boss fight. That dog is Hewie of fellow Capcom horror title ''VideoGame/HauntingGround''. Additionally, [[VideoGame/ResidentEvil5 Tricell's]] emblem can be seen on billboards in Ascension City from the 2009 ''VideoGame/BionicCommando'' sequel. Throw in the explicit fact that ''Street Fighter'', ''VideoGame/FinalFight'', ''VideoGame/SaturdayNightSlamMasters'', ''VideoGame/CaptainCommando'', and (maybe) ''VideoGame/RivalSchools'' are part of a singular timeline, some possible inter-series cameos in Ken's ''VideoGame/StreetFighterAlpha 2'' stage, and the suggestion from ''VideoGame/NamcoXCapcom'' that the various series are part of one greater world merely separated by time and space, and the implication is that these series all share some degree of cohesive continuity but Capcom doesn't really bother to go further in-depth outside of the ''[[CapcomVsWhatever Vs.]]'' series (and sometimes not even then).
* This is the entire premise of ''VideoGame/WarriorsOrochi'', being a crossover between ''VideoGame/SamuraiWarriors'' and ''VideoGame/DynastyWarriors''. Though, that hasn't stopped them from adding guests from ''other'' titles, including ''VideoGame/DeadOrAlive'', ''VideoGame/NinjaGaiden'' and even ''[[VideoGame/SoulSeries Soul Calibur]]''.
* The upcoming sequel to ''TransformersFallOfCybertron'', ''Rise of the Dark Spark'', crosses over the ''War for Cybertron'' universe with Michael Bay's [[Film/Transformers live-action universe]], during the events of TransformersAgeOfExtinction.
[[/folder]]

[[folder:Web Comic]]
* [[http://www.drunkduck.com/Crossoverlord/index.php?p=386131 The Crossoverlord]]. (Yes, that's the name of the comic and the no space is intentional.)
** Now has a sequel called [[http://www.drunkduck.com/Crossoverkill/index.php?p=752922 Crossoverkill]]
* Unwinder of ''Webcomic/UnwindersTallComics'' adopted ''ComicStrip/{{Marmaduke}}''. Then, in the ''Comicbook/{{Watchmen}}'' parody comic, the big dog dies à la Jon Osterman. According to the author, "It's not ''Tall Comics'' canon, but it IS ''Marmaduke'' canon."
* In a guest strip for ''Webcomic/{{PvP}}'', Kris Straub proposed that his comic ''Webcomic/{{Starslip}}'' takes place in the same universe, just thousands of years later, and his characters are descendants of those in ''Webcomic/{{PvP}}''. [[WordOfGod Scott Kurtz]] said it's canon, though maybe he was joking.
** Another guest strip by [[ComicStrip/FoxTrot Bill Amend]] had Jason taking over '''[=PvP=]'' while Cole was away. [[TheKnightsWhoSaySquee Scott claimed that it was canon.]]
* ''[[http://www.whiteponyproductions.com/comicstrips/ctc/present.htm Cross Time Cafe]]'': Characters from at least five different webcomics are regular cast members - though half the cast appears more here than in their own comics (the main exceptions being [[Webcomic/{{Freefall}} Florence]], [[Webcomic/TwentyFirstCenturyFox Jack and Jenny]].
* ''Webcomic/SomethingPositive'' is practically some sort of MassiveMultiplayerCrossover nexus of webcomics. (See that article for more.)
* ''Webcomic/TheCartoonChroniclesOfConroyCat'' has the story take place in [[ToonTown Cartoon Land]], [[http://dtoons.com/conroy/ and has cartoon characters from different series making appearances]].''
* ''Webcomic/PowerpuffGirlsDoujinshi'' starts with ''WesternAnimation/ThePowerpuffGirls'' and ''WesternAnimation/DextersLaboratory'', but also brings in ''WesternAnimation/JusticeLeague'', ''Film/MenInBlack'', ''WesternAnimation/MegasXLR''..and well pretty any series that catches Creator/{{Bleedman}}'s fancy.
** Likewise with ''Webcomic/GrimTalesFromDownBelow'' which has even more crossover such as ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy'', ''WesternAnimation/DannyPhantom'', ''WesternAnimation/TheNightmareBeforeChristmas'', ''Comicbook/{{Spawn}}'', etc. Yes Bleedman just really likes doing these.
* A storyline running through both ''Webcomic/KevinAndKell'' and ''Webcomic/GeneralProtectionFault'' had Nick and Ki "crossing over" to Domain.
* ''WebComic/HelloCthulhu''
[[/folder]]

[[folder:Web Original]]
* ''[[http://www.starwreck.com/ Star Wreck: In The Pirkinning]]'', a Finnish ''Series/BabylonFive''/''Franchise/StarTrek'' crossover movie that took seven ''years'' to make. So good, it's apparently the most-watched Finnish film, and Universal Studios are distributing an updated version.
* [[http://www.howitshouldhaveended.com/ How It Should Have Ended]] gives their take on how the ''Franchise/{{Terminator}}'' series [[http://www.youtube.com/watch?v=bBBw9E2Q_aY&feature should end]]. With an [[Film/BackToTheFuture unexpected crossover]].
* ''WebVideo/ImAMarvelAndImADC'' has Marvel and DC characters (and occasionally characters from other continuities, such as ''Comicbook/{{Hellboy}}'') arguing with each other about whose comics and movies are best. Then there's the "After Hours" series which has actual storylines involving characters from both continuities, in the same vein as the official Marvel/DC crossovers.
* [[WebVideo/DragonBallAbridged Ghost Nappa]] has been in a [[WebVideo/YuGiOhTheAbridgedSeries duel]], [[WebVideo/VisionOfEscaflowneAbridged Atlantis]] and Creator/{{Lanipator}} and Kaiser Neko's hotel room.
** And seeing as he had a Poke Ball prior to his death, perhaps he also, at some point, visited [[Franchise/{{Pokemon}} another continuity]].
** He's also been spotted in [[Manga/SoulEater Death City]].
* There was a competition between most of the major Fantasy series - based on popular opinion, not on what makes any sense. For example, [[Literature/TheWheelOfTime The Dragon Reborn]], [[Literature/TheDresdenFiles Harry Dresden]], [[Literature/TheKingkillerChronicle Kovthe]] all lost to muggles. Each one had a written description of the battle - and despite the implausibility, ''it was awesome''.
* ''WebAnimation/DeadFantasy'', a {{Machinima}} series which pits ''Franchise/DeadOrAlive'' heroines and ''Franchise/FinalFantasy'' heroines against each other. And it is ''glorious''.
* CodeMent and ''WebVideo/NonePiece'' cross over in episode 14.5/6. It's even more incoherent than usual.
[[/folder]]

[[folder:Western Animation]]
* According to the special ''The Grim Adventures of the Kids Next Door'', ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy'', ''WesternAnimation/CodenameKidsNextDoor'', ''WesternAnimation/EdEddNEddy'', and ''WesternAnimation/ThePowerpuffGirls'' all take place in the same universe.
** Since [[WesternAnimation/DextersLaboratory Dexter, Boy Genius]] has been sighted in Townsville, we can add his show to this list as well.
* ''Franchise/{{Transformers}}'' and ''Franchise/GIJoe'' have a long history of crossovers, which includes ''WesternAnimation/{{Inhumanoids}}'' and ''WesternAnimation/{{Jem}}'' through the shared character of sensationalist TV reporter Hector Ramirez (a Geraldo Rivera parody). The original comic books had a special crossover miniseries, and recent comics have revisited the crossover in various ways. The old eighties cartoons, meanwhile, shared a reality: in the futuristic third season of ''Transformers'', major character Marissa Faireborn was the daughter of ''G.I. Joe'' character Flint, and [[http://tfwiki.net/wiki/Only_Human one episode]] featured a washed-up Cobra Commander doing business under the pseudonym "Old Snake."
* Creator/{{Nickelodeon}}'s shows ''WesternAnimation/TheFairlyOddParents'' and ''WesternAnimation/TheAdventuresOfJimmyNeutronBoyGenius'' had three cross-over {{Made For TV Movie}}s: "The WesternAnimation/JimmyTimmyPowerHour", "Jimmy-Timmy II: When Nerds Collide", and "Jimmy-Timmy III: Jerkinators". Also ''WesternAnimation/RugratsGoWild''
* DisneyChannel took this to another extreme with ''WesternAnimation/LiloAndStitchTheSeries'', doing [[http://en.wikipedia.org/wiki/List_of_Disney_Channel_crossovers#Lilo_.26_Stitch:_The_Series several specials]] that crossed it over with a bunch of the other shows on Creator/DisneyChannel. This fits with the movie's initial marketing push, showing Stitch crossing over with various Disney movies, wrecking the place, and being told to get his own movie.
** And, as a result, aliens are now {{canon}} in ''WesternAnimation/{{Recess}}'' and ''WesternAnimation/TheProudFamily''... Which seems kinda odd, considering how relatively realistic their premises were. Though it does somewhat fit with ''WesternAnimation/TheProudFamily'''s usual weirdness. Penny's great-aunt canonically has telekinetic powers.
** And the fact that, by extension, ''WesternAnimation/AmericanDragonJakeLong'' is set in the same universe as ''Disney/LiloAndStitch'', ''WesternAnimation/KimPossible'', and ''WesternAnimation/{{Recess}}'' has lots of strange implications...
** It's ''very'' confusing with ''WesternAnimation/{{Recess}}'', as it's made explicitly clear in the series that it takes place over the course of the Fall of 1997 until the Summer of 1998 (and then Fall 1998 for ''Recess: Taking the Fifth Grade''), even for the episodes made in the 2000s (this is firmly established in ''WesternAnimation/RecessSchoolsOut'')
** Made even worse when you realize that Lilo and Stitch were originally from the Franchise/DisneyAnimatedCanon, which means that all of the Disney Channel cartoons take place in the same universe as all of the Disney animated features... [[OhCrap EEK!]]. Though it is also strongly implied that each of the Disney Canon films take place within their ''own'' canon (Final Fantasy style) [[ThemeParkVersion frivolous crossovers]] notwithstanding.
* In one episode of ''WesternAnimation/DuckDodgers'', Dodgers gets his dry cleaning mixed up with [[Franchise/GreenLantern Hal Jordan's]] and ends up as the newest Green Lantern when he finds the power ring in Jordan's uniform pocket.
** The episode name, for the curious, is ''The Green Loontern''. And in another episode (''Samurai Quack'') Dodgers takes the place of WesternAnimation/SamuraiJack. Complete with Achoo, voiced by Mako himself.
* ''WesternAnimation/TheSimpsons''
** Homer's claim to having had a close encounter with an extraterrestrial is investigated by none other than [[Series/TheXFiles Agents Scully and Mulder]]. [[http://media.screened.com/uploads/0/5735/318691-thesimpsons_super.jpg The Agents asked if any of the following aliens are familiar]]: [[WesternAnimation/LooneyTunes Marvin the Martian]], Series/{{Alf}}, [[Franchise/StarWars Chewbacca]], and [[Film/TheDayTheEarthStoodStill1951 Gort]]. Writer Mike Reiss described it as the "most illegal shot" in the show's history.
** In a move which infamously pissed off Groening, Jay Sherman from ''WesternAnimation/TheCritic'' comes to help judge a film festival. An episode made after ''WesternAnimation/TheCritic'' was canceled has Jay turn up again, this time confined to an insane asylum and only able to say his CatchPhrase, "It stinks!"
*** He appears again, along with other one-time characters voiced by JonLovitz.
-->'''Artie Ziff:''' Idiots.
** [[Franchise/ArchieComics "D-uh! You stay out of Riverdale!"]]
** [[WesternAnimation/KingOfTheHill "We drove 2000 miles for this?"]]
** [[Series/TwentyFour "It's okay. That was Shelbyville"]]
** [[Series/{{Cheers}} "Just gimme another beer, you braindead hick! I'll kill you! I'll kill all of you!"]]
** [[Franchise/{{Dragnet}} "Gee, Joe. You haven't been the same since your son went crazy in Vietnam"]]
* Creator/GregWeisman has written a [[http://www.s8.org/gargoyles/askgreg/search.php?rid=843 Gargoyles/ Spectacular Spider-Man crossover radio play]], although it is unofficial and non-canon.
** There were also plans to do a crossover when it seemed there would be a series version of ''Disney/AtlantisTheLostEmpire'', called ''Team Atlantis.'' Set in the '20's, it would have involved the ''Atlantis'' cast getting involved in a battle between Demona and a former Hunter.
** However, that hunter has reappeared in the comics, and Demona was seen grabbing something out of the remains of the Praying Gargoyle [[spoiler: an Atlantean crystal]].
* In an ad for ''WesternAnimation/{{Metalocalypse}}'', [[VideoGame/BrutalLegend Eddie Riggs]] apparently served a stint as a roadie for Dethklok.
** In another ad, the band summons [[VideoGame/DarksidersII the Horseman Death directly from his game.]] [[MundaneMadeAwesome He grants them a wish for pizza.]]
* Most of Creator/HannaBarbera's cartoons.
* WesternAnimation/TheMask and AceVentura met for two episodes that could have been awesome. Both shows kept their respective styles of animation in each other's universe (Ace & Spike, for example, kept their more cartoony look in the Mask's more realistic world and vice versa).
* Due to both characters being from ManOfActionStudios to begin with, ''WesternAnimation/GeneratorRex'' had a special episode named ''WesternAnimation/Ben10GeneratorRexHeroesUnited'', involving Rex meeting [[WesternAnimation/{{Ben10}} Ben Tennyson]] (the [[WesternAnimation/Ben10UltimateAlien Ultimate Alien]] incarnation). A rare canon example, as it reveals more about Rex's backstory and provided Ben with a new alien form that actually made it to the next sequel series.
* ''WesternAnimation/{{Freakazoid}}'' gave us [[http://www.youtube.com/watch?v=2NLrjVnMO7k this little scene]].
** Also, [[WesternAnimation/{{Animaniacs}} the Warners]] had a brief cameo in the segment "Freakazoid And Friends".
* ''WesternAnimation/ScoobyDooWrestlemaniaMystery''. While Scooby and the gang have [[WesternAnimation/TheNewScoobyDooMovies teamed up with celebrities before]], this is the first time Wrestling/{{Kane}} has chokeslammed Shaggy.
[[/folder]]
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