->''"Oh, no another fan with ideas..."''
-->-- '''Actor!Sokka''', ''WesternAnimation/AvatarTheLastAirbender''.

Ultimately, {{Canon}} is much smaller than the people who throw the term around like to think it is. {{Canon}} is limited to that which has actually been described in the source material. Especially in groups of writers, it boils down to what the writers specifically need to worry about for the purposes of the ongoing plot.

'''Fanon''', also known as the generally accepted term 'Headcanon' among fanfic writers and Roleplay crowds, is the set of theories based on that material which, while they generally seem to be the "obvious" or "only" interpretation of canonical fact, are not actually part of the canon. Occasionally, the explanation seems good enough to just be [[CommonKnowledge "common sense."]] The salient point to remember is that when someone shouts, "That episode was terrible because it violates canon!", they are very often totally incorrect.

Fanon fills in holes that the writers may have deliberately left in order to have [[CanonFodder fodder for later stories]]. In addition to arising from a point of vagueness in the canon, Fanon can come into existence as a fact gained from a [[WordOfDante popular but non-canonical]] [[FanFic source]], or taken from a different Adaptation. Because many fans mistake their own Fanon for actual {{Canon}}, they tend to get riled up when a new fact is introduced [[SchrodingersGun which does not literally contradict anything canonical]], but [[{{Jossed}} invalidates what were formerly the most obvious assumptions]]. Many examples of {{Retcon}} and ContinuityDrift that are imagined to be violations of {{Canon}} really only ''explicitly'' contradict {{Fanon}}.

Popular subjects of Fanon include character backstories, full names of characters with NoNameGiven, what characters actually do for a living, and {{Shipping}} a whole other world of its own.

Since many creators in the aftermarket [[ExpandedUniverse series universe]] are fans, Fanon often shows up there, and if those creators in turn [[RunningTheAsylum start writing for the actual show]], Fanon may actually [[AscendedFanon become]] {{Canon}}. Alternatively, you just have MemeticMutation within the fandom.

Fanon often also refers to the body of information provided by [[WordOfGod otherwise-official sources]]. Television and movie scripts are a continuing source of fanon material [[Series/StarTrekTheOriginalSeries Captain James Kirk]], for example, had a middle initial ("T.")...but his actual middle ''name'' ("Tiberius") was originally revealed in an episode of the ''Trek'' [[WesternAnimation/StarTrekTheAnimatedSeries animated series]]; since that show's canonicity is debatable, it was considered "fanon" until revealed canonically in the 6th ''Star Trek'' movie. Note that this usage blurs the line between fanon and ''[[WordOfDante deuterocanon]]'', though.

Warning: Fanon and accusations of Fanon are a classic InternetBackdraft, with the accusation commonly leveled by fans that have a different [[AlternateCharacterInterpretation interpretation of the material]] even when their theory is just as vulnerable to SchrodingersGun.

Compare BroadStrokes, where the events of a story are referenced in passing without taking everything said and done as having "officially" happened. If the fanon was repeatedly hinted at by writers until it became fanon, but never actually confirmed in canon, it's WriterInducedFanon. See also FandomSpecificPlot. Not to be confused with [[http://en.wikipedia.org/wiki/Frantz_Fanon this]] Fanon or [[http://en.wikipedia.org/wiki/Papal_Fanon the Pope's robe]]. Fanon is frequently based off FanficFuel.
* Fanon/AnimeAndManga
* Fanon/ComicBooks
* [[Fanon/{{Film}} Film - Live Action]]
* Fanon/{{Literature}}
* Fanon/LiveActionTV
* Fanon/VideoGames
* Fanon/WebComics
* Fanon/WesternAnimation

!!Franchise-Specific Fanons:
* Fanon/HarryPotter
* Fanon/JamesBond
** Fanon/CasinoRoyale
** Fanon/{{Skyfall}}
* Fanon/MarvelCinematicUniverse
* Fanon/{{Pokemon}}
* Fanon/SherlockHolmes
** Fanon/{{Sherlock}} -- the BBC TV series.
* Fanon/TolkiensLegendarium, including ''The Lord of the Rings''


[[folder:Film Animation]]
* ''Disney/TheLionKing''.
** Many fans think Simba and Nala had a son, named Kopa, who was either then killed by Zira, or otherwise died, or is at least gone somewhere awaiting a fanfic plot that re-unites him with his lost family (sometimes he just leaves to start his own pride while other times he got lost or was driven away as a cub). A confusing example, as Kopa was a character in the semi-canonical or non-canonical storybook ''The Lion King: Six New Adventures'' published between the 2 movies, but was then never mentioned in the 2nd film. This has been speculated to be due to grief, but it's more likely that he was just {{retconned}} out of existence. It's thought that he, and not Kiara, was the cub pictured at the end of the original movie. It's also due to the cub's coloration at the end of the first movie (resembling Simba's at the beginning, having male markings, and all the lionesses are a lighter color).
** It's required in fanfics that if Kiara and Kovu have a son, he be named Tanabi.
** Considering the other Lion King movies aren't officially in the DisneyAnimatedCanon (which doesn't necessarily mean anything to the Lion King universe), some fans just dismiss Kiara's existence completely and replace her with Kopa.
** Nala was meant to have a younger brother named Mheetu but he was taken out of the final product. Fans often include him in fan-works, either as her unseen brother or her dead sibling.
*** Mheetu is often shown to be albino or at least white furred. This comes from fans mistaking the uncolored art for his official color.
** Due to the fact the writing says he has green eyes and black fur while the art makes him look like Mufasa, many fans have taken the third option with Ahadi (Mufasa's father) and combined the two elements; the most common combination is his artwork build but with the colors of the text, though his eyes will occasionally look like his youngest son (Scar). His mate, Uru, often has dark brown fur with a patch on her forehead.
** Nala being Scar's daughter is a very common theory. That'd make Nala and Simba related but it's a pretty well-known {{fanon}} that they're cousins.
*** Similarly Kovu is often considered Scar's son by many, even if the movie goes out of its way that he is not. Vitani and Nuka are almost across-the-chart considered Scar's daughter, though there's a sum of fans who believe Vitani is Nala's daughter with Scar. It's less common to believe she's Nala's and ''Simba'''s child, with her getting certain genes from both her parents.
* ''ThePrincessAndTheFrog''
** Despite (or because of) the fact he's from a fictional country, many fans still throw FanWank fits over Prince Naveen's "real" ethnicity namely, [[AmbiguouslyBrown whether he was closer to Mediterranean or Middle Eastern and/or Indian on the sliding scale of Ambiguous Brownness]]. That is until some people picked up on a throwaway line in "Friends on the Other Side" ("You come from '''two''' long lines of royalty") and ran with it. The final conclusion? [[http://halcyonjazz.livejournal.com/314517.html?thread=9736341#t9736341 He's all of them]].
** There's also the matter of Tiana being outbid on the restaurant. It has generally become accepted amongst fans that the "other buyer" story was orchestrated by the mill's owners, either with them outright lying or with them getting someone to outbid Tiana's offer. While this does explain why Tiana conveniently is outbid the very day she tells the owners she's ready to purchase the place (and why no "other bidder" gets angry when Tiana has Louis scare them into selling), there's no official explanation for it in-movie.
* ''Film/HowToTrainYourDragon'' fan fiction seems to have reached the consensus that a) Toothless is the LastOfHisKind and b) Toothless is [[spoiler: responsible for accidentally severing Hiccup's foot.]]
** A lot of fans believe Astrid and Ruffnut are good friends (some even like to [[LesYay ship them]] but that's a different matter). While it's a reasonable assumption to make as Ruffnut is the only other named teenage girl living on Berk (hell, except for Valka, Heather and Gothi she's the only other significant female character in the ''franchise!'') there's nothing to indicate that Ruffnut is any closer Astrid than any other member of the gang, beyond the fact that they were paired up for the Zippleback training exercise in the first film.
* ''Disney/TheSwordInTheStone''. Many fans were so saddened by the heartbroken girl squirrel that several fanfics have emerged in which Merlin turns her into a human so she and Arthur can be together. Popular fan names include Hazel and Gwen. These stories are accepted by many as legitimate {{Canon}} just because they want so much for the poor little thing to have a happy ending.
* WesternAnimation/ToyStory
** The fandom has it that (SPOILERED for {{Rule 34}}) [[spoiler: Woody's pull-string is a sort of erogenous zone, since he lacks the necessary parts for sex. And by extension, Jessie as well, as she has a pull-string too.]]
** Also, unless you ship Buzz/Woody or Woody/Dolly or Woody/Jessie, [[spoiler: the figurine of Bo Peep was bought by Bonnie or her mother and is reunited with Woody.]]
** Many fans theorize that Andy's mom was Jessie's original owner, Emily. There's no confirmation on this, but [[WildMassGuessing it would explain why she let her son keep a pair of toys that all but materialized in her house out of nowhere]]. [[note]] Also: eagle-eyed fans have noted that Andy's cowboy hat actually resembles [[http://images.huffingtonpost.com/2014-02-25-Andy1.jpg Jessie's]] [[http://images.huffingtonpost.com/2014-02-25-Andy3.jpg hat]] more than it resembles Woody's hat, leading many to theorize that it's part of a "Jessie the Cowgirl" costume that his mother owned as a child. Plus, Jessie's flashback seems to give the impression that Emily was a child in the 1960s, which would make her about the age of Andy's mother.[[/note]]
** A similar and not always exclusive theory is that Andy inherited Woody from his father, who is not seen in the films and is assumed to have left or died when Andy was very young. This would explain both why Andy has a toy modeled after a show from the 1950s, and why he's so attached to it.
* In ''WesternAnimation/{{Cars}}'' fan fiction, the name of the agency Finn and Holley work for is called C.H.R.O.M.E, which is derived from the video game adaption, but the agency's name is never actually stated in the film itself.
* ''RiseOfTheGuardians'' had the issue of [[spoiler: Jack's sister's name.]] Since she was voiced by the same actress who voiced Pippa (one of Jamie's friends) but never named in the actual film, most people thought that [[spoiler: Pippa was Jack's sister instead]]. Since it's now been clarified, the general name used is Emma, although some fic writers will substitute with their own preference.
** There are also a few [[WildMassGuessing theories]] about [[spoiler: Baby Tooth being a reincarnation of Emma, since [[http://riseoftheguardians.wikia.com/wiki/Baby_Tooth they have the same beauty mark under their right eyes.]]]]
* Lord Shen, the BigBad of ''WesternAnimation/KungFuPanda2'', once had a backstory that involved him being neglected by his parents due to being a sickly albino and left in the care of the Soothsayer, who acted as his nanny. This was ultimately dropped in the final film, but it's rare to find a Shen fanfic that doesn't incorporate it anyway. This is somewhat justified, as the canon interactions between Shen and the Soothsayer do support this, and there's nothing in the film that really contradicts it either.
* Even if you don't [[FanPreferredCouple ship Elsa]] and [[BrotherSisterIncest Anna]] from ''Disney/{{Frozen}}'', a large portion of the fanbase views Elsa as being [=LGBT=] (typically lesbian) due to her not having a canon male love interest and that ''Film/XMen'' has taught a generation of film-goers that "a secret power that you are born with but are forced to hide but that you then learn to embrace, making you an happier person in the process" = Gay.
** Elsa quickly reached MemeticSexGod levels and this naturally occurred. She's typically depicted as an aggressive lover, at tamest a rather dominant partner.
** Due to the fact she appears in a short cameo in "For The First Time In Forever," and Anna resembles her to controversial levels, [[Disney/{{Tangled}} Rapunzel]] is often seen as being related to the sisters, most often her cousin.
** Anna having powers, typically earth or fire, is common.
** In modern [=AUs=] Elsa is always an introverted, socially incompetent hikikomori. She's often an architect major in college while Anna is an art or business major.
*** "Summers" and "Winter(s)" if the girls are unrelated, "Anderson", and "Arendelle" if they are, are the most common surnames for the girls in modern [=AUs=].
*** In modern AU's the princesses are usually upper middle class though not royalty or politically involved. For whatever reason they're usually presented as Norwegian-Americans as well.
*** Sven is almost always a dog in modern AU's. Olaf is usually either made an adult human who either works for the girls parents or is friends with them, though fics where Anna and Elsa are a couple but not related often make him their child.
** If you're going to put Hans back in somehow, his job or his first job ''must'' be a stableboy and shovelling horse poop, as that's a fairly good punishment for him.
*** Hans' ConspicuousGloves are almost always given a lot of emphasis... in particular, he's often shown keeping them on during sex. Not necessarily explained, he just does.
** The bishop seen at Elsa's coronation is usually given the name "William" or some variant thereof
** "Agdar" and "Idun" are almost always the names chosen for Anna and Elsa's parents when they do show up in a fanfic, based on translation of the Runic inscriptions on their gravestones
* There's a frequently cited belief that all the {{Pixar}} films take place in one universe, due to Pixar themselves having dropped lots of different subtle references, such as the recurrence of the Pizza Planet truck.
* Mirage from ''WesternAnimation/TheIncredibles'' being a Super is quite popular, though no one consensus has been decided on her powers.
* ''Disney/BigHero6'':
** Since Honey and [=GoGo=] are only known by their nicknames, fans have speculated that their respective real names are Aiko Miyazaki and Leiko Tanaka, much like their comic counterparts. Though this is highly unlikely due to their RaceLift to Latina and Korean.
** Much of the fanfiction and fanart out there depicts Tadashi as being alive with severe burn scars, but not much more, likely due to his EnsembleDarkHorse status. It's become a joke within the members of the fandom that the movie's canon must have been false. Tadashi's obviously just in some hospital healing, and will definitely be back in the sequel, if there is one.
** Honey Lemon being a Disney princess, or even being descended from [[{{Disney/Tangled}} Rapunzel]].

* {{Vocaloid}}: The only things [[WordOfGod officially canon]] are the characters' names, appearances, and voices. Usually. (Some have a couple more minor things, like age and height, while others only have a name and a voice.) Personalities, backstories, relationships, and some characters are pure fanon.
* Music/PinkFloyd:
** Fans have generally accepted that [[MadArtist Pink]], the protagonist of ''Music/TheWall'', was born "Floyd Pinkerton", and that "Pink Floyd" is his stage name. In the original album, he's only referred to as "Pink" and "Mr. Floyd" in two separate moments, but the movie adaptation includes a brief scene where his deceased father's name is given on a memorial plaque as "J.H. Pinkerton", and one of Pink's friends can be heard calling him "Pinky" (a logical nickname for someone with the surname "Pinkerton") in another scene.
** Though somewhat less unanimous than the above theory, many fans also believe that ''The Final Cut'', Music/RogerWaters' final album with the band, is partially an epilogue/continuation of ''The Wall''. In particular, many have theorized that the titular song, "The Final Cut", is told from Pink's perspective as he contemplates suicide sometime after recovering from his mental breakdown, and that "When the Tigers Broke Free" is about the death of his father. The latter point is supported by the film version of ''The Wall'', which actually includes "When the Tigers Broke" in the soundtrack, but it's unknown if Waters actually wrote the song with Pink in mind.

[[folder:Newspaper Comics]]
* Many fans believe that ''ComicStrip/{{Garfield}}'' and Jim Davis's lesser-known second strip, ''ComicStrip/USAcres'', take place in the same universe. While this is true on the ''WesternAnimation/GarfieldAndFriends'' side, it's never been confirmed or debunked in the strips.

[[folder:Tabletop Games]]
* The [[http://mimir.net/mapinfinity/ordial.html Ordial Plane]] is a concept that turns up very frequently in ''{{Planescape}}'' fan work, based on the assumption that the Astral and Ethereal Planes should have a third counterpart in accordance to the RuleOfThree and which would complete the circle between the Inner, Outer, and Material Planes.
* WarhammerFantasy deliberately leaves a lot up in the air concerning some of its mysteries, but a great deal of fanon proclaims definitive answers to these questions. One common example is the nature of the Bretonnian goddess: many fans declare that she is merely a deception by the Wood Elves to be holy writ, but this is only one of several possibilities vaguely hinted at by the actual canon.
* The above applies to Warhammer's sister game ''TabletopGame/{{Warhammer 40000}}'' as well. There are fans who insist that the Eldar created the Tau Ethereals, based on some vague hints in the Xenology book, which had a decidedly UnreliableNarrator (and the narrator himself dismissed the idea out of hand.)
** [[http://suptg.thisisnotatrueending.com/archive/4027777/images/1237573586142.jpg Apparently]], the [[AmazonBrigade Sisters of Battle]] are beautiful, {{pyromaniac}}al, trigger-happy {{Tsundere}}s. All of them. Or (after [[http://1d4chan.org/wiki/Sisters_of_Battle#Sisters_Snuff certain updates]]) they are The [[{{Woobie}} Pointlessly Martyred]] Squad. Which [[WoobieDestroyerOfWorlds isn't mutually exclusive]]. Except [[CombatSadomasochist sadomasochistic]] and [[NaughtyNuns scantily clad]] Repentia, but that's less of fanon and more an interpretation of [[http://wh40k.lexicanum.com/wiki/Sisters_Repentia the original imagery]].
** Fanon tends to paint the [[UnfortunateName Rainbow]] [[SpaceMarine Warriors]] as being Mayan/Aztec/Inca-themed... [[FridgeLogic which makes]] quite a lot of sense because there was an [[ShownTheirWork Native American myth of a being called The Rainbow Warrior who will defend all life]].
* Many players assume Abyssal {{Exalted}} are undead. They're actually living people "tainted by the essence of the Underworld", much like {{Half Vampire}}s in many other settings.
* [[http://farcastblog.com Farcast]] is fanon for many {{Eclipse Phase}} fans.

* ''{{Hamlet}}'' is a breeding ground for these, due partly to centuries of theatrical interpretation and partly to EveryoneIsJesusInPurgatory induced by high school English classes. Thus, for instance, many people take it for granted that Hamlet is genuinely mad instead of faking it.
* The ''LittleShopOfHorrors'' fandom often gives Audrey's full name as Audrey Fulquard. This surname is from ''TheLittleShopOfHorrors'', the B-movie on which the musical is--very loosely--based.

[[folder:Visual Novels]]
* ''UminekoNoNakuKoroNi'' is a case where {{Fanon}} is actually ''encouraged'' by the author. Ryūkishi wants the readers to have their own ideas and reach their own conclusions about [[WildMassGuessing the plot]] and [[AlternateCharacterInterpretation the characters]]. Very few answers about the mysteries are revealed explicitly; but most readers end up acknowledging a certain conclusion (namely that [[spoiler:Beatrice, Kanon and Shannon are one and the same]]) even if the story never outright states it. [[AdaptationExpansion The manga]] tends to be a bit more explicit on some aspects though.

[[folder:Web Original]]
* In ''{{Neopets}}'', a popular fanmade Neopian Times piece ("Poor Dr_Death") managed to define everything pertaining to the owners of the pound/adoption center. Most notably, the anonymous Uni was given a name, and nobody has found cause to dispute Dr_Death's characterization as a lovable DeadpanSnarker. (At least, not until his official appearance suddenly became ''much'' LighterAndSofter with the rest of the website, but that's another issue.)
* It's become {{Fanon}} in the shipping community that [[WebVideo/AskThatGuyWithTheGlasses Ask That Guy]] is WebVideo/TheNostalgiaCritic's twin brother and that he lives in his house. And that they're [[{{Twincest}} very close.]]
** And that The Other Guy is the older, slightly saner brother that the Critic goes to when he needs to lick his wounds.
** Again with them, any fic that takes place when they were younger calls them Doug and Guy. For common sense purposes really, it'd be silly for their parents to call them "Critic" and "Ask That Guy".
** Its become AscendedFanon that they're brothers, as Ask That Guy recently referred to Rob as his brother.
** Spurred by Ask That Guy's love of his pipe and Doug's penchant for blowjob jokes, Critic being ''really'' good at oral has become almost a meme in fics.
** Also that Dr. Insano's son is named "SOI" (Son Of Insano). And he goes to school.
** After {{Kickassia}} was finished, it's usually accepted that the Critic was exiled to a hotel room and the others had fun on his tab. What tends to happen [[DisproportionateRetribution next]] is, unfortunately, wishful thinking.
** Given that an entire episode was based around ''married'' [[WebVideo/DemoReel Donnie]] having a LoveTriangle with two men, it's commonly assumed that he wrecked his miserable marriage by having an affair.
* [[MoeAnthropomorphism Humanized versions]] of the ''HappyTreeFriends'' characters almost always follow a certain design set by fanon. For example, Flaky is always a petite woman with messy, hip-length hair coated in what is probably supposed to be dandruff.
* Machinima/RedVsBlue has a lot of these. According to an inordinate number of fans...
** Wash and CT had a romantic relationship, despite only interacting ''twice'' in the show. (In fairness, both times implied they were closer than most Freelancers, but he doesn't even react when [[spoiler:she turns traitor... or when the Freelancers attack Charon Industries to capture or kill her]]. Alternately, Grif/Simmons. While Tucker does make a remark about them being in love, their relationship in the show is pretty much just ordinary HeterosexualLifePartners.
** Crunchbite was reincarnated as Junior. There's some evidence for this in the series, but it's far from explicitly said.
** Epsilon is metastable/rampant. Metastability in the Halo universe is, to borrow a phrase from the forums, a big f***ing deal, involving some very obvious and extreme stages. Epsilon hasn't really exhibited any of these (except maybe anger) and it's likely he's not even capable of it (being a fragment, not a full AI), yet it's such a common fan theory that it's often stated as fact, even on ThisVeryWiki.
** Carolina's nickname (often given to her by York) is Lina. She's never called anything but Carolina in the show, though, even by York. Alternately, her real name is Carol and she almost always is shown using the gravity hammer, despite using it just twice in the series--pistols or melee are much more part of her fighting style, yet fans have latched onto the grav hammer instead.
** Sarge was previously an ODST. It is mentioned that Sarge jumped out of ships "during the war", so it's possible, but again, it's far from confirmed.
** Character appearances have been pretty well cemented by Luke [=McKay's=] fan art, leading most people to believe Caboose is a blonde, Grif and Simmons have brown hair, Tex has red hair, Church has black hair and stubble, etc. While Church's appearance has sort of been confirmed ([[spoiler:the Director indeed looks like an older, even grumpier Luke [=McKay=] Church]]), some of the others are definitely not correct (Tucker is implied to be black, unlike Luke McKay's white depiction, and Tex is a blonde... [[spoiler:or at least the original Allison was]]).
* ''Podcast/WelcomeToNightVale'': Partly as a result of the series suddenly going very viral after a long slow burn, there is a {{Fanon}} interpretation of [[TheNarrator Cecil's]] appearance that many people mistake for {{Canon}}--including living tattoos, tentacles, purple eyes, blond hair, and glasses. Canonically, everything we know about Cecil's physical appearance comes from Kevin's [[SuspectIsHatless non-description]] of his picture during The Sandstom.
* ''WebAnimation/{{RWBY}}'' lemon fics nearly always depict Pyrrha, [[TeamMom of all people]], as an aggressive lover. This is probably an extrapolation of the scene where she pins her crush to a tree to, um '[[ItMakesSenseInContext partner]]' with him.
* ''WebComic/{{AwfulHospital}}'' gave birth to an entire community founded around roleplaying as {{Eldritch Abomination}}s, found at ''Website/{{AwfulHospitalRoleplayForum}}''
* It's never outright stated in [[WebVideo/MatthewSantoro Matt Santoro's]] videos, but it's a common fan theory that [[TheDitz Hugo]], Matt's clone, also has the last name Santoro.