History Retcon / WesternAnimation

* Katara was originally written as the only member of the ''WesternAnimation/AvatarTheLastAirbender'' main cast to be alive during ''WesternAnimation/TheLegendOfKorra''. Somewhere in the development of future seasons they decided that Zuko was also alive, and in the last book the viewer learns that [[spoiler:Toph]] is alive but WalkingTheEarth. That means at least half of the "[[FanNickname Gaang]]" is alive, though whether Suki is alive or not is [[WhateverHappenedToTheMouse never mentioned]].

** ''The Simpsons'' FloatingTimeline being what it is, this retcon actually makes sense. The Simpsons' time exists on a sliding line, so even though every episode happens in "the present", the past keeps moving forward. Also note that while the kids' ages [[NotAllowedToGrowUp never change]], Marge and Homer have been, albeit very slowly, getting older; being in their mid-thirties in early episodes and now nearing forty (presumably to reflect the aging American population), which does leave a gap for the events of "that 90's show" to take place.

** Jimbo Kern, Stan's uncle, has been inconsistently portrayed as being both Sharon's and Randy's brother over the course of the series, but an interview with series co-creator Creator/MattStone established him as being Randy's half-brother; as they were birthed by the same mother but share different fathers, explaining the discrepancy between their surnames. However, despite this confirmation, Sharon referred to Jimbo as her brother in ''The Pandemic Special'', which directly contradicts what fraternity has previously been established. This may possibly be an error, as South Park has never consistent with these topics. A similar situation exists with Marvin Marsh, a wheelchair-bound 102-year-old who previously lived with Randy and Sharon. Earlier episodes were ambiguous about the Marsh family tree, with both Sharon and Randy referring to Marvin as their father. As the series progressed, though, he was more heavily implied to be Randy's father, sharing his surname as well. It was first hinted by implying a genetic link between Marvin's addictions, Randy's drinking problem, and Stan's own addiction issues in notably "Freemium isn't Free", and later by Marvin describing his son's conception in "Nobody Got Cereal?".

** Jimbo Kern, Stan's uncle, has been inconsistently portrayed as being both Sharon's and Randy's brother over the course of the series, but an interview with series co-creator Creator/MattStone established him as being Randy's half-brother; as they were birthed by the same mother but share different fathers, explaining the discrepancy between their surnames. However, despite this confirmation, Sharon referred to Jimbo as her brother in ''The Pandemic Special'', which directly contradicts what fraternity has previously been established. This may possible be an error, as South Park has never consistent with these topics. A similar situation exists with Marvin Marsh, a wheelchair-bound 102-year-old who previously lived with Randy and Sharon. Earlier episodes were ambiguous about the Marsh family tree, with both Sharon and Randy referring to Marvin as their father. As the series progressed, though, he was more heavily implied to be Randy's father, sharing his surname as well. It was first hinted by implying a genetic link between Marvin's addictions, Randy's drinking problem, and Stan's own addiction issues in notably "Freemium isn't Free", and later by Marvin describing his son's conception in "Nobody Got Cereal?".

** Jimbo Kern, Stan's uncle, has been inconsistently portrayed as being both Sharon's and Randy's brother over the course of the series, but an interview with series co-creator Creator/MattStone established him as being Randy's half-brother; as they were birthed by the same mother but share different fathers, explaining the discrepancy between their surnames. However, despite this confirmation, Sharon referred to Jimbo as her brother in ''The Pandemic Special'', which directly contradicts what fraternity has previously been established. This may possible be an error, as South Park has never consistent with these topics. A similar situation exists with Marvin Marsh, a wheelchair-bound 102-year-old who previously lived with Randy and Sharon. Earlier episodes were ambiguous about the Marsh family tree, with both Sharon and Randy referring to Marvin as their father. As the series progressed,though, he was more heavily implied to be Randy's father, sharing his surname as well. It was first hinted by implying a genetic link between Marvin's addictions, Randy's drinking problem, and Stan's own addiction issues in notably "Freemium isn't Free", and later by Marvin describing his son's conception in "Nobody Got Cereal?".

** Jimbo Kern, Stan's uncle, has been inconsistently portrayed as being both Sharon's and Randy's brother over the course of the series, but an interview with series co-creator Creator/MattStone established him as being Randy's half-brother; as they were birthed by the same mother but share different fathers, explaining the discrepancy between their surnames. However, despite this confirmation, Sharon referred to Jimbo as her brother in ''The Pandemic Special'', which directly contradicts what fraternity has previously been established. This may possible be an error, as South Park has never consistent with these topics. A similar situation exists with Marvin Marsh, a wheelchair-bound 102-year-old who previously lived with Randy and Sharon. Earlier episodes were ambigous about the Marsh family tree, with both Sharon and Randy referring to Marvin as their father. As the series progressed,though, he was more heavily implied to be Randy's father, sharing his surname as well. It was first hinted by implying a genetic link between Marvin's addictions, Randy's drinking problem, and Stan's own addiction issues in notably "Freemium isn't Free", and later by Marvin describing his son's conception in "Nobody Got Cereal?".

** Jimbo Kern, Stan's uncle, has been inconsistently portrayed as being both Sharon's and Randy's brother over the course of the series, but an interview with series co-creator Creator/MattStone established him as being Randy's half-brother; as they were birthed by the same mother but share different fathers, explaining the discrepancy between their surnames. However, despite this confirmation, Sharon referred to Jimbo as her brother in ''The Pandemic Special'', which directly contradicts what fraternity has been previously been established. This may possible be an error, as South Park has never consistent with these topics. A similar situation exists with Marvin Marsh, a wheelchair-bound 102-year-old who previously lived with Randy and Sharon. Earlier episodes were ambigous about the Marsh family tree, with both Sharon and Randy referring to Marvin as their father. As the series progressed,though, he was more heavily implied to be Randy's father, sharing his surname as well. It was first hinted by implying a genetic link between Marvin's addictions, Randy's drinking problem, and Stan's own addiction issues in notably "Freemium isn't Free", and later by Marvin describing his son's conception in "Nobody Got Cereal?".

** ''Another'' retcon with "Sponge on the Run" occurs when [=SpongeBob=] has a flashback of adopting Gary at Kamp Koral. In the Season 8 episode "Treats!", [=SpongeBob=] looks at a photo of himself adopting Gary at the ''pound''.

* 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 Santa Clause.

** In one ''Oh Yeah! Cartoons'' episode Vicky mentions having a little brother. This brother was never heard from again but instead she has a little sister named Tootie.

** Blukic and Driba were only introduced in ''WesternAnimation/Ben10Omniverse'', but they had [[RememberTheNewGuy allegedly been around the whole time even though we had never seen them]]. Flashbacks in-between the original series and ''WesternAnimation/Ben10AlienForce'' inject them into the continuity even though there was never any mention of them. The real kick is they had been on Earth since Max was young, and were actually the first aliens to officially make contact with humans, being the [[RoswellThatEndsWell alien captured during the Roswell Incident]].

* ''WesternAnimation/ReadyJetGo'': Due to the episodes airing out of production order, there are some. For example, the kids mention having a treehouse in "Jet 2", but they build the treehouse in "Treehouse Observatory".

** Remy was PutOnTheBus for 4 seasons until season 9's ''Country Clubbed''. Despite being a reoccuring antagonist of Timmy's, the episode acts as if the two have never met. The episode also depicts Remy as not having a fairy and even [[YouDontLookLikeYou gave him a redesign]].

** The fact that Maggie shot Mr. Burns has been gradually retconned 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 suspiciously replies "That would have made a lot more sense..." Then, in season 18, Homer in a passing moment outright claims that he framed Maggie.

*** (2) In the same flashback in season 8, Icy is shown to have had natural curly blonde hair before changing it to straight and silver-blue, but in the season 3 episode ''The Black Willow's Tears'' when Icy, Darcy, and Stormy are regressed to children, Icy is shown with natural straight silver-blue hair.[[note]] It is of note that some fans use this episode as so-called "proof" that the Trix aren't actual sisters (the dubbing errors of the 4kids and Rai dubs of the episode where Stormy comments that they're friends don't help. It's worth pointing out that the 4kids dub was infamous for creating numerous [[DubInducedPlotHole Dub-Induced Plot Holes]] and the Rai dub was not without its own errors, such as claiming Tecna was a cyborg. The Nick dub, however, corrects this by having Stormy accurately say they're sisters) due to the fact that after the Trix are turned back into children, Icy comments on Darcy's hair, "Your hair used to look like that?", leaving some fans wondering why she wouldn't remember how she used to look if they were really sisters. However, the reason is simply that they forgot how they used to look when they were kids, which isn’t all that shocking since there are a lot of people who forget how they and their siblings/relatives used to look when they were younger, especially if they look ''vastly'' different than how they used to when they were young[[/note]].

** Coinciding with EarlyInstallmentWeirdness, in a season one episode Twilight is [[TakenForGranite turned to stone]] by looking a cockatrice in the eye. When she's later unfrozen, she appears to have no knowledge that any time has past. In later seasons, however, it is said explicitly by [[GodOfChaos Discord]] that a person remains fully aware and conscious while petrified. This is further confirmed in season nine when Maud's boyfriend, Mudbriar, is petrified by a cockatrice and remembers the experience.

** 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 meeting in the 90s now seems increasingly unlikely if they're supposed to be in their 30s.

** The series has gone through a retcon as of the 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, but the series was retconned in the aforementioned episode. Marge in previous episodes had never gone to college, but was suddenly attending in the mid 90's; it led us to believe 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 be retconned since, though with the floating timeline it means Homer and Marge should be older than their 30s.
** Prior to this the characters were stuck in the 90's and never aged.
** ''The Simpsons'' time line being what it is, this retcon actually makes sense. The Simpsons' time exists on a sliding line, so even though every episode happens in "the present", the past keeps moving forward. Also note that while the kids' ages [[NotAllowedToGrowUp never change]], Marge and Homer have been, albeit very slowly, getting older; being in their mid-thirties in early episodes and now nearing forty (presumably to reflect the aging American population), which does leave a gap for the events of "that 90's show" to take place.

*** (3) Her actions (knowingly endangering the lives of/attempting to murder people for ''fun'', which started as early as ''episode 3''; stating she ''liked'' being evil and was actually annoyed at being referred to as anything less; assaulting ''children'', Flora's sister Miele and Mitzi's sister Macy, who happen to be little sisters like [[CousinOliver Sapphire]]) and motivations (wanting to become powerful for the repeated explicit purpose of ''conquering'' the Magic Dimension) ever since the beginning of season 1 ''do not'' align whatsoever with what season 8 is trying to establish her goals to be.

*** (6) And most importantly, the creator of the show, Iginio Straffi, [[https://www.corriereadriatico.it/SPETTACOLI/rainbow_avventure_winx_iginio_straffi_villa_musone_marche_rai2/notizie/421983.shtml actually had the story all planned out and was going to end the series after season 3 (with the first movie being the "grand finale" of the series)]], but since Winx became such a cash cow franchise, it got renewed for a fourth season and continued after that, so it ''cannot'' be said that this was planned from the start.

* A minor one in ''WesternAnimation/{{Wakfu}}'': in Season One, [[SealedEvilInACan Rubilax]] and his fellow Shushu Shadowfang are described by the former as a "[[ElementalPower four-element and five-element Shushu]]. In season 2, she's instead described as a "Level-5 Shushu" without explanation.

*** (6) And most importantly, the creator of the show, Iginio Straffi, actually had the story all planned out and was going to end the series after season 3 (with the first movie being the "grand finale" of the series), but since Winx became such a cash cow franchise, it got renewed for a fourth season and continued after that, so it ''cannot'' be said that this was planned from the start.

*** (1) Her actions (knowingly endangering the lives of/attempting to murder people for ''fun'', which started as early as ''episode 3''; stating she ''liked'' being evil and was actually annoyed at being referred to as anything less; assaulting ''children'', Flora's sister Miele and Mitzi's sister Macy, who happen to be little sisters like [[CousinOliver Sapphire]]) and motivations (wanting to become powerful for the repeated explicit purpose of ''conquering'' the Magic Dimension) ever since the beginning of season 1 ''do not'' align whatsoever with what season 8 is trying to establish her goals to be.
*** (2) Icy claims to not be powerful enough to undo the spell the shaman witch placed on Sapphire... ''except'' she has been shown to be skilled at transmutation, having transformed Mirta into a pumpkin in season 1 and (along with Darcy and Stormy) turned Griffin into a crow in season 6. There's also the fact that Icy, Darcy, and Stormy have been receiving powerful upgrades throughout the series and in seasons 6 and 7, have been shown to be stronger than the ''Winx'' on several occasions, becoming their strongest in season 7 when they achieved ''Shape-Shifting'' Witch forms derived from the power of magical animals, so the excuse of Icy not being powerful enough falls flat.
*** (3) Near the end of season 8, Icy decides to help the Winx because she "can't stand to see another world crumble" even though when she revealed Bloom's heritage to her in season 1, she smugly told her how the Ancestral Witches, ''her'' ancestors, destroyed her home world Domino and throughout the series had been (along with Darcy and Stormy) allying with villains whose plans involved ''destroying'' worlds (Ex. Tritannus) with no objections and was attracted to Valtor, someone who destroyed Domino alongside her ancestors, because of how ''evil'' he was.
*** (4) And most importantly, the creator of the show, Iginio Straffi, actually had the story all planned out and was going to end the series after season 3 (with the first movie being the "grand finale" of the series), but since Winx became such a cash cow franchise, it got renewed for a fourth season and continued after that, so it ''cannot'' be said that this was planned from the start.