History Retcon / WesternAnimation

** In a season two episode, Ozai and Iroh's father Azulon is said to have been Fire Lord for 23 years. The Nick website also provided a brief backstory for Sozin saying that he was a young man when he became Fire Lord shortly before Roku died and was prevented from starting the war until the elder Avatar Roku's death, and that Sozin ruled for the first 70 or so years of the 100 year war. Come season three, it's revealed that Sozin and Roku are actually the same age and that he was an old man when he started the war. In response, the creators stated that Sozin ruled for only the first 20 years of the war before Azulon took over for the next 75 years before Ozai became the Fire Lord for the last 5 years, contradicting what is said in the season two episode.
** Katara mentioned early on that the Fire navy shipwreck near her village has been around since her grandmother was a little girl. Fast forward to the end of the season where we learn that Katara's grandma isn't even from the Southern Water Tribe and didn't arrive there until she was no younger than sixteen. And ''then'' a season 3 flashback shows that ship being frozen roughly 60 years earlier, and by that point Gran Gran was already in her early twenties, meaning the original statement isn't even MetaphoricallyTrue.

** The series most dramatic and controversial retcon occurred in the 2008 episode, "That 90's Show." In the earlier episodes, Homer and Marge attended high school in the late 1970's got married three or four years after graduating from high school after Marge became pregnant with Bart, Bart was born in 1980, Lisa was born in 1982, and Maggie was born in 1989, and the show took place in the 1990s, with the characters never aging. By the 2000s, however, this timeline had become increasingly implausible, and was given a hard reset in "That 90's Show." Homer and Marge were now shown to have met in what appears to be the mid 1990s, which implies the kids were born in the early 2000s. Other changes were made as well: Marge in previous episodes had never gone to college, but was now established as having attended in the mid 90's; Homer had a Grunge band, whereas in an earlier episode he didn't understand grunge at all; and they also showed us that they dated for at least ten years before getting married and having the kids, who are now retconned into being born in the early 2000's. "That 90's Show" itself seems to have been since retconned, with "the past" now depicted far more generically, rather than tied to any specific decades. Presumably this is because in the 2020s, even the idea of Homer and Marge being college-age in 90s now seems increasingly unlikely if they're currently supposed to be in their 30s.

*** Also on the subject of Mr. Burns, he started out at 81 years old (the early episode where Homer defrauds the plant's health insurance for hair growth), but is now canonically 104 years old.
*** Mr. Burns had been mentioned to be 104 as early as season 6. Although, his age is basically debated, many of his other mentioned possible ages place him as being older than 104, some place him at ''118'', others at '''122'''.

** [[Series/TheDailyShow Jon Stewart]] once pointed out to Matt Groening in an interview, Homer and Marge were supposed to be in their late 30s. They got married when they found out Marge was pregnant with Bart, but since Bart is only 10, about a decade would had to have passed between high school and Bart being conceived. Lisa even lampshaded said plot hole in the episode.
** A season 3 episode (''Bart the Murderer'') establishes Fat Tony's name as William "Fat Tony" Williams. Several seasons later, he's canonically named Anthony "Fat Tony" D'Amico. It's either a case of this or [[SeriesContinuityError the writers forgetting they already named him.]]

** An explicit retcon occurred in the season 9 episode "The Principal and the Pauper", where it was revealed that Seymour Skinner is actually an impostor, originally born as Armin Tamzarian and having moved to Springfield to assume the life and identity of the real Skinner. Apparently, none of his past prior to becoming the principal of Springfield Elementary is his own. Needless to say, this contradicts a very large deal of prior material, particularly the evidence that he served as a sergeant in the Vietnam War. This turn of events was particularly unpopular among both fans and staff alike (Matt Groening even personally considers the episode non-canon) and the retcon is mentioned only once in later episodes.
** The fact that Maggie shot Mr. Burns has been gradually retconned back into an unsolved mystery as part of MythologyGag about the controversy and implausibility of that being the answer to the famous "Who Shot Mr. Burns" mystery of Season 6-7. In the season 9 episode "The Cartridge Family" Homer says "I thought Smithers did it?" to which Lisa agrees, in a suspicious tone, "that would have made a lot more sense..." Then, in season 18, Homer in a passing moment outright claims that he framed Maggie. In Season 22, Homer at one point instructs the viewer to go back and look for clues as to who "really" shot Mr. Burns. Marge scolds him that it was Maggie, but Homer seems unconvinced -- "Oh sure, a ''baby'' shot a guy."
** The episode "Do Pizzabots Dream Of Electric Guitars?" will depict Homer as a teenager in the 1990's, whereas early seasons had him as a teen in the 1970's, this is because as the years go on, this becomes more and more unlikely that the early seasons could've happened.
** The episode "Manger Things" depicts Maude Flanders pregnant with Todd when Bart was four and Lisa was two, whereas past episodes had Todd being Bart's age and "Lisa's First Word" had him being around before Lisa was born.

** Luanne's father/Peggy's brother didn't appear until near the end of the series, though was mentioned several times. Originally, he had fled to an oil rig in fear of his [[DoubleStandardAbuseFemaleOnMale abusive ex-wife]], refusing to come back on land until Hank faxed him her death certificate. Bill mentions him looking like a male version of Peggy while Hank mentions getting along with him. When he shows up, however, he is revealed to have actually been in jail for years for being a con artist and thief, a fact which Peggy hid from everyone with the oil rig story. He also looks nothing like Peggy and it seems that Hank had never met him before. This change calls forth several bits of FridgeLogic: one, Luanne is supposed to have seen the event that caused him to flee to the oil rig; how does his incarceration fit into that event, especially since we know her mom was put in jail herself for that abuse? And if she was already in jail, why did Peggy (and later Hank) think it would be so traumatizing for Luanne to also know that her father was as well? Also, they established several times that Luanne witnessed the fight between her parents that led to her mom stabbing her dad with the fork which occured in the very first episode where she was about 16 or 17, but in this episode her dad claims the last time he seen her she was a little girl about five years old and she has no memory of the event.

** Another would be the origin of Dale's Rusty Shackleford identity, in a couple of early episodes he mentions he got the name from a boy who died from smallpox back in the 1950's, however it was later retconned in the season 11 episode "Peggy's Gone To Pots" where he supposedly got it from a boy who went to his school and moved away and Dale thought he died, and the "real" Rusty Shackleford arrives to tell him to stop using his name.

** In the original pilot, Vicky was apparently babysitting Timmy for the first time, and Timmy was ten. The first [[TheMovie movie]] retconned both points: Vicky had been Timmy's babysitter for a year, and Timmy was nine when he first got Cosmo and Wanda.

** Jesse Bannon herself was a retconned version of Jesse Bradshaw, a character who appeared in an episode from the 80's series ''The New Adventures of Jonny Quest''. The original Jesse was not related to Race Bannon.

** Kyle's background possibly got retconned. It's been mentioned a few times throughout the series that he moved to South Park when he was four; however, "It's a Jersey Thing" has him specifically saying that he was born "here," despite his parents moving from New Jersey while pregnant with him. [[WildMassGuessing Maybe he meant "here in Colorado," but not South Park specifically?]]

** In the fourth episode, it is stated that Roger has been living with the Smiths for four years since Stan rescued him from the C.I.A.. This is backed up (sort of) in "A.T., the Abusive Terrestrial" which features a flashback of Stan giving him to Steve as a little boy for his 10th birthday (Steve's 14). However, in "Hayley Smith, SEAL Team Six", Roger remembers Hayley when she was six, even though Hayley would have been either 14 or 15 when Steve was 10.

-->'''Francine''': Stan, we had a dog already.\\
'''Stan''': I don't think so.\\
'''Francine''': We did! Five years ago, you got Steve a dog that peed dust and you killed him. We also had another dog named Fussy that you didn't like or something.\\
'''Stan''': Francine, [[HandWave those were obviously dreams]], and [[BellisariosMaxim I refuse to discuss your dreams in the daytime.]]

*** Not only do the retcons only makes things more confusing, but they are also [[VoodooShark contradictory]], as Megatron/Galvatron's imprison and subsequent absorption of Unicron's power took place in year 2013/2014 timeline-wise, but Planet X existed and was destroyed in a war that took place in the ''sixth century''.

** In both "The Legend Of The Gobblewonker" and "Fight Fighters", Stan mentions "The guys at the lodge", implying that he's in a secret society with fezzes like his own. However by "Gideon Rises", it's shown that Stan has almost no friends in Gravity Falls and the possibility of him in a club is never mentioned again. ''Literature/GravityFallsJournal3'' officially retcons the origin of the fez as [[spoiler: taken from his father Filbrick Pines, who was in an group called The Royal Order Of The Holy Mackerel.]]
** In "Society Of The Blind Eye", [[spoiler: a young Fiddleford]] mentions that he's helping a "visiting researcher" as if he's a native of Gravity Falls. But flashbacks in "A Tale Of Two Stans" and ''Literature/GravityFallsJournal3'' show that [[spoiler: Fiddleford]] grew up in rural Tennessee before attending Backupsmore. By the time The Author calls him about his project, he's living in Palo Alto, California.

** In "Lethal Inspection", [[spoiler:we see the real story of Bender's birth after he told a different version. Rather than being born full-sized just a few years ago, he was born as a baby-shaped robot with a visibly-younger Hermes as his inspector.]] Completely worth it for that song.

** "The Why Of Fry". This fourth-season episode posits that the original accident causing Fry to be frozen and sent forward into the year 3000 was actually intentionally caused by Nibbler and the Nibblonians so that he could save the universe from the giant space brains. At first glance, this seems like a retcon; however, careful viewing of the original first episode shows the shadow of Nibbler underneath the desk as the accident happens and in a revisited scene his eye stalk poking out, proving that the [[TheProducerThinksOfEverything producers of the show set this up from the very beginning.]]

** In "Something Smells", when Patrick is monologuing about how ugly he is, he mentions that he doesn't have a sister. This is retconned in a later episode called "Big Sister Sam", where Patrick's long lost sister, Samantha, visits. This could, however, be interpreted as Patrick attempting to repress a traumatic memory (the loss of his sister), rather than a retcon.

** Katara mentioned early on that the Fire navy shipwreck near her village has been around since her grandmother was a little girl. Fast forward to the end of the season where we learn that Katara's grandma isn't even from the Southern Water Tribe and didn't arrive there until she was no younger than sixteen.

*** The reboot series ''A New Wish'' retcons Timmy's future yet again, with him ending up looking like his fat and balding self from the original series episode "The Big Problem!".

*** The reboot series ''A New Wish'' retcons Timmy's future yet again, with him ending up as an actor and looking like his fat and balding self from the original series episode "The Big Problem!".

*** The reboot series ''A New Wish'' retcons Timmy's future yet again, with him ending up as actor and looking like his fat and balding self from the original series episode "The Big Problem!".

* Twice in the first season of ''WesternAnimation/FanboyAndChumChum'', they mention the Christmas holiday as if they celebrate it (Fanboy says the word "Christmas" in "Eyes on the Prize" while Yo mentions Santa Clause in "Night Morning"). Come the second, it is shown they celebrate ''[[YouMeanXmas Icemas]]'', a holiday that's like Christmas but with ice, and Man-Arctica is their equivalent of SantaClaus.

** {{Lampshade|Hanging}}d in the 9th season episode "Excellence in Broadcasting": When the Griffins hear that Creator/RushLimbaugh is coming to town to promote his latest book, Chris recalls that, during Lois' brief stint at Creator/{{Fox News|Channel}} (in the "Foxy Lady" episode), she reported that both Limbaugh and Michael Moore were characters played by Creator/FredSavage. Lois [[{{Handwave}} dismisses]] this, explaining that even if something is true to begin with it becomes a lie when said on Fox News.

** [[Series/TheDailyShow Jon Stewart]] once pointed out to Matt Groening in an interview. Homer and Marge were supposed to be in their late 30s. They got married when they found out Marge was pregnant with Bart, but since Bart is only 10, about a decade would had to have passed between high school and Bart being conceived. Lisa even lampshaded said plot hole in the episode.

*** The [[NoExportForYou Japan-only]] Beast wars shows were initially set concurrently with the American ones, with Lio Convoy and the likes hailing from same time period as Primal. However, the anime staff completely contradicted this(whenever on purpose or accident is unclear) and had the cast as descendants from thousands of years after the WesternAnimation/BeastWars cast. Several retcons were needed in order to accommodate this, the biggest one being the discrepacy of Vector Sigma's portrayal and appearance between [[WesternAnimation/BeastMachines Beast Machines]] and [[Anime/BeastWarsNeo Beast Wars Neo]] of Cybertron(it becomes technorganic on the finale of the former, and in the latter, supposedly thousands of years later its back to a fully mechanical world with no explanation), which was explained in a [[https://tfwiki.net/wiki/Legends_Comic:_Bonus_Edition_Vol._EX_(Blue_Big_Convoy) Japanese comic]].

** Another retcon with ''Sponge on the Run'' features scenes where SpongeBob met Patrick and Squidward, which retcon both "The Secret Box" where SpongeBob has known Patrick since they were babies, and "Truth or Square" when [=SpongeBob=] first met Squidward as an adult.

** The Season 25 episode "The Big Fix" has a particularly hilarious one. When Randy gets Stan to invite Token's family over to dinner so that he can have a black best friend to improve the image of his weed business, Randy asks what the deal is with Token's name. Only for him and Stan to learn to learn that Token's name is actually ''Tolkien'', as in the [[Creator/JRRTolkien influential fantasy writer]], not TokenMinority. Stan is additionally shocked to learn that {{everybody knew already}}, with all past instances of Tolkien's name being written as "Token" getting handwaved as misspellings. When he directly states what he thought Tolkien's name was to his doctor, the man calls him a terrible person for ever believing such a thing, before [[BreakingTheFourthWall turning to address the audience]] to insult us for ever thinking the same as well. This one sort of borders on OrwellianRetcon since this episode as Subtitles for previous seasons where Tolkien's name is uttered (still pronounced Token, obviously) have been updated to say Tolkien.

** On the show's website it suggests that Kyoshi was born on the island later named after her, yet we later find out that it wasn't even an island until she made it one.

* The ''WesternAnimation/AdventureTime'' episode "The Witch's Garden" implies that Jake's shapeshifting powers were the result of him [[ToxicWasteCanDoAnything playing in a puddle of nuclear waste.]] "Joshua and Margaret Investigations" retcons this and reveals the true origin of his shapeshifting powers: [[spoiler:An alien shapeshifter [[FaceFullOfAlienWingWong impregnated Joshua,]] and their DNA combined to birth Jake.]]

** In a season two episode, Ozai and Iroh's father Azulon is said to have been Fire Lord for 23 years before Ozai. The Nick website also provided a brief backstory for Sozin saying that he was a young man when he became Fire Lord shortly before Roku died and was prevented from starting the war until the elder Avatar Roku's death, and that Sozin ruled for the first 70 or so years of the 100 year war. Come season three, it's revealed that Sozin and Roku are actually the same age and that he was an old man when he started the war. In response, the creators stated that Sozin ruled for only the first 20 years of the war before Azulon took over for the next 75 years before Ozai became the Fire Lord for the last 5 years, contradicting what is said in the season two episode.

** In the fourth episode, it is stated that Roger has been living with the Smiths for four years since Stan rescued him from the C.I.A., however in a much later episode there's a flashback of Stan giving him to Steve as a little boy for his 10th birthday.

* ''[[Toys/{{Bionicle 2015}} BIONICLE: The Journey to One]]'' starts with a recap of the previous year's online animations, in which the six heroes, the Toa find golden masks to gain ElementalPowers. It is also shown that [[BigBad Makuta]] was defeated by knocking the Mask of Ultimate Power off his face in an empty field, with the ensuing explosion of energy trapping him in the "Shadow Realm" and flung the mask far away. ''Journey to One'' rewrote Makuta's defeat, showing it took place in a city, the mask had been smashed to pieces rather than flying off intact, and the explosion took the entire city and its people with Makuta into the Shadow Realm. At the end the Toa also learn the elemental powers were within them the whole time. These retcons are due to the show being CutShort -- in place of the originally planned multi-season plot, the writers [[WrapItUp quickly had to make something up]] to end the series under two episodes.

''WesternAnimation/GravityFalls'':

** As for the whole 90's retcon, it helps to clear up one glaring ''PlotHole'' that [[Series/TheDailyShow Jon Stewart]] once pointed out to Matt Groening in an interview. Homer and Marge were supposed to be in their late 30s. They got married when they found out Marge was pregnant with Bart, but since Bart is only 10, about a decade would had to have passed between high school and Bart being conceived. Lisa even lampshaded said plot hole in the episode.