History SeriesContinuityError / WesternAnimation

** "Lisa's First Word" has the family anticipate hearing Maggie's first spoken word, becoming a RunningGag that Maggie [[TheVoiceless rarely speaks]] onscreen or around others. Maggie clearly says "good night" to Homer in the first Tracy Ullman short, "Good Night", though events in the shorts may not have [[CanonDiscontinuity happened]].

** Grim becomes the Grim Reaper on at least three separate occasions. To list them: When his parents told him it was his "destiny" as a child and forced him into it, despite his desire to sing; found out his true calling, also as a child, but kept up the image of being a country rocker for over a millenia to please his father, and got the 'once in an eternity' school election to be one, competing with [[HarmlessVillain The Boogey Man]] and [[BigBad his]] [[RememberTheNewGuy old]] [[ChildhoodFriends Childhood Friend]] [[DemonicSpiders from]] ''[[TheMovie Wrath of the Spider Queen]]''. The probably only concrete thing about his reaping origins (at least in two of them) is that he started doing it as early as cavemen and/or dinosaurs.

** Comicbook/{{Cable}} is introduced as a mercenary who has been living in the present for quite some time, and it's mentioned that he'd taken part in a coup in Genosha several years ago. Later episodes would establish that he was actually a freedom fighter from the year 3999, and that he'd specifically time-traveled back to the 90's to SetRightWhatOnceWentWrong. Also, he inexplicably lacked his bionic arm in his two appearances, despite having it in all his subsequent guest spots.

* ''WesternAnimation/TheLegendOfKorra'': In season 3, metalbenders (a Red Lotus mook and Suyin) are able to bend liquid metal when Metalbending is actually achieved by moving chunks of earth trapped inside solid metal, causing the metal to bend and warp into the desired shape, which would obviously be impossible for a liquid, even if we were to accept that solid bits of earth were somehow safely forced into and subsequently pulled out of Korra's bloodstream.

* ''WesternAnimation/TheFairlyOddParents'' has a lot of Continuity Errors, especially in [[SeasonalRot latest seasons]].

* Similar to the ''[=SpongeBob=]'' example below, ''WesternAnimation/TheFairlyOddParents'' episode "Double-Oh-Schnozmo!" introduces Cosmo's [[LongLostUncleAesop brother Schnozmo]], despite that the earlier episode "The Gland Plan" said that Cosmo didn't have any siblings.

** The episode where Squidward becomes nice has [[BrokenStreak Squidward actually beating [=SpongeBob=] for Employee of the Month at the Krusty Krab]]. The problem with this is that, in ''WesternAnimation/TheSpongebobSquarepantsMovie'' (which is the chronological series finale [[WordOfGod according to the creator]]), [=SpongeBob=] says he has won that award 374 times in a row. Note that winning employee of the month that many times (let alone in a row) means he's been working at the Krusty Krab for a minimum of 31 years and a bit.

* ''WesternAnimation/SamuraiJack'': In the season 5 reboot, Jack slices the throat open of one of the Daughters of Aku and is horrified when he realizes he has killed another human (as Aku had only sent machines and supernatural entities after him prior to this, he had supposedly avoiding killing any humans up to this point). However, he actually did face several human Bounty Hunters in "The Princess and the Bounty Hunters" with the episode in question indicating he killed them without issue. [[WordOfGod Series Creator Genndy Tartakovsky]] claims that [[HandWave they were all either not human or didn't die after all]], but admits to having completely forgotten about the episode in question.

** There's also, of course, the infamous "That '90s Show" episode in Season 19, which made many fans angry since it does away with all continuity. It practically erases anything that happened prior to Season 10 or so, by saying that Homer and Marge did not even have kids during the 90s. "The Way We Was" all the way back from Season 2, the episode where Homer and Marge meet, is explicitly set in 1974. That means Marge and Homer took more than 20 years to get married. Clearly the episode did away with the continuity just for the laughs, but it truly does mess the whole timeline up, even if it is a floating timeline.

* Just a few of the more famous ones from the ''Franchise/{{Transformers}}'' franchise:
** A total list of all instances in ''Franchise/TransformersGeneration1'' would fill a library, as continuity wasn't considered to be terribly important. Autobots fly! Now they don't! Surprise, I have [[NewPowersAsThePlotDemands a built-in tool]] to solve today's problem! [[ForgottenPhlebotinum Now I don't]]! However, there are a few that do affect the big picture:
*** The Constructicons. Their introduction discusses the Decepticons building them in the caves they were in at the time. Omega Supreme's backstory, however, involves how the already-existing and formerly good (ignore the Decepticon symbols already on them, please!) Constructicons were turned evil by Megatron. ''Megatron's'' backstory? He was created by the already-existing, ''already-evil'' Constructicons! That's three Constructicon origins, none of which are at all compatible with either of the others.
*** The Matrix of Leadership. The powerful artifact containing the wisdom of all past bearers [[NewPowersAsThePlotDemands and other mysterious properties as needed]] has been in Optimus' chest ''all along?'' There was no sign of it when he took major damage to the area it was eventually shown to be held in, and some people still aren't buying it.
*** In TheMovie, Unicron turns Skywarp and Bombshell into ''two'' identical robots that he refers to as "Cyclonus and his armada." A ''second'' Cyclonus is a rather poor "armada..." and only one Cyclonus is ever seen again. Who became Cyclonus and what happened to the other? Good question. (Oh, and Bombshell ''is seen again, not as Cyclonus.'' Voiced in-character, so not one of [=TFG1's=] zillions of "oops, we used the wrong animation model" cases.)
*** Awesomely {{Lampshaded}} in a comic that came with the Rodimus Vs. Cyclonus figures, but written by SimonFurman, so ''not'' the usual toy pack-in fluff. At one point, Cyclonus complains that he hasn't gotten any respect in ''either'' of his lives (referencing having been someone else on a ''few'' occasions, without ever saying who he used to be) and that he was supposed to get his own troops but they never materialized. Rodimus would later say to him "I don't know who you are, or even who you used to be, and I don't care!" as they get ready to fight.[[note]]The toy itself contains a continuity error: Rodimus is in his original car form, in which he was called Hot Rod, but his toys are all sold under the more trademarkable name "Rodimus" no matter the form. (Also handled amusingly and appropriately in the comic: Rodimus would either have to be called by a name that defies the toy the comic is packed with, or a name that is at odds with the story. As such, he never has ''either'' of his names spoken.)[[/note]]
*** The Coneheads are explicitly destroyed twice, and are just there again next time, without comment.
*** As stated before, those are the ''biggies,'' the ones affecting continuity (in a show that's pretty episodic). Rare is the ''G1'' episode that doesn't have ''something'' in this category. Not that the other series are completely innocent, but G1 episodes were often rushed, and not checked for things like this, resulting in errors at the macro (Constructicons, Cyclonus and his armada) and micro (Ironhide goes to van mode and is robot mode in the very next shot and stays that way, Starscream's voice comes from his PaletteSwap Thundercracker in one shot) levels being ridiculously common.
** And, of course, the Anime/UnicronTrilogy, a dub of three series that were originally a ''duology'' and an independent series. Calling it a continuation makes ''Anime/TransformersCybertron'' a continuity headache, where characters who were dead are back without comment (or, in Sidewaysï case, without ''anyone remembering him.'') and a great many characters who were important [[BrotherChuck never turning up again]], and a couple of returning characters having ''radically'' different personalities, most glaringly Wing Saber. TheMasquerade is in effect and only Agent Franklin suspects there is something to the alien robots thing, though humans have known of, and worked alongside, Cybertronians for years as of the previous series. That's by no means the whole list of inconsistencies. [[AllThereInTheManual Read the supplementary materials]] if you want it all explained in a way that [[ContinuitySnarl arguably makes it all worse]].
* In her first episode in ''WesternAnimation/TheReplacements'', Celebrity Star is arranged as Shelton's girlfriend, because she likes out-of-shape, whiny nerds like him. She proves too clingy and oppressive for him... and finally dumps him when he proves to be a middle-school hunk without his glasses. Her next appearance has her making a movie intended to ruin ''his'' reputation for dumping ''her.''
* ''WesternAnimation/{{Recess}}''
** The VagueAge of Cornchip Girl. She appears to be in first or second grade, but spends most of her time with the kindergarteners, and during the PictureDay episode, she's not shown among the crowds having her picture taken.
** Not to mention Gus being the new kid in school in fourth grade, yet somehow also appearing in kindergarten, as well as how he appears to be attending school at the time of the Great Jungle Gym standoff (this can be attributed to an animation goof; since he doesn't have any lines). This is addressed in one of the later episodes. Apparently, he ''did'' spend some time in the same kindergarten as the others, but being little children, they had forgotten.
** Also, The Ashleys are shown to be in another class in the ''Can Drive'' episode -- yet several other episodes show them sitting in the ''exact same class'' as the main gang.

* ''WesternAnimation/{{Duckman}}''
** The show features several conflicting flashbacks depicting how Duckman and Cornfed first met.
** Season 1's "Civil War" has them meeting in a store Cornfed worked at, with Duckman being an obnoxious customer that he saves ''three'' times from a robber.
** Season 3's "The Girls of Route Canal", however, shows Duckman encountering Cornfed years earlier at an airport while looking for Beatrice. This one was explicitly a subversion played for laughs, as Cornfed attempts to introduce himself and help Duckman, but the mallard is in full JerkAss mode, so he barely even acknowledges him outside of insults.
** Finally, Season 4's "From Brad to Worst" shows them as long-time friends in high school. The writers may've been aware of the error, but this one was ''not'' played for laughs.

* ''WesternAnimation/CodenameKidsNextDoor'': In a show with surprisingly good continuity, "Operation: C.O.L.L.E.G.E." has the other kids kidnapping Numbuh One from Professor XXXL, and not even batting an eyelid when XXXL says he's using Numbuh One for his snowcone research... even though his snowcone research was the plot twist of his previous appearance ("Operation: A.R.C.T.I.C.").
* ''WesternAnimation/{{Arthur}}''
** In an episode, Sue Ellen is seen in a Kindergarten class photo when in fact she transferred in third grade.
** In another episode Muffy was shown in a Kindergarten flashback but she moved to Elwood City in the second grade.
** Another episode has Pal present when Arthur and D.W were younger, even though he was gotten when they were still their present age.
** In one episode D.W.'s mother calls her by her full name: Donna Wilson. A later episode revolves around D.W. hating her full name: Dora Winifred.
** In a flashback of Arthur's Baby, a baby Mr Ratburn is called Emil by his mother while he scrawls multiplication sums on the wall. However, in future episodes, his first name is said to be Nigel.
** Mr. Haney's first name is Herb in the episodes "Arthur's Mystery Envelope" and "The Chips Are Down", but later episodes give him the name Francis.
** Mrs. [=MacGrady=]'s first name was originally Sara, but in "The Great [=MacGrady=]", it was changed to Leah, presumably in memory of Leah Ryan, who co-wrote the episode and passed away before it was completed.
* ''WesternAnimation/{{Futurama}}''
** In season 4, it is established that talking about ''Franchise/StarTrek'' is illegal, although numerous references to it were made in the first three seasons, including a fictitious movie that was ''nominated for an Oscar'' for Best Product Placement (and on top of that, Creator/LeonardNimoy from the original ''Star Trek'' series is in the celebrity head museum[[note]]while his other cast mates were sent off into space. In "Where No Fan Has Gone Before", Nimoy stated that he stayed because he had a six-month lease on his apartment and couldn't turn down the offer[[/note]]. In the first episode, he was a greeter, but in "Where No Fan Has Gone Before," Nimoy is now on one of the main shelves). Lampshaded on the DVD commentary.
-->"''They never said 'Star Trek,' they said 'Start Wreck!'''"
** In the pilot, Bender claims that "I don't need to drink, I can stop anytime I want!" This contradicts the fact that robots in ''Futurama'' are powered by alcohol, established in episode three, "I, Roommate". Later episodes would establish alternate fuel sources like mineral oil and efficient synthetic fuels as being possible.
** In season 3, the professor specifies that there exist only two parallel universes (the other one seems to be the same as this one except that everyone wears cowboy hats). In season 4, an entire episode revolves around jumping through multiple parallel universes. But perhaps one can argue that the professor's machine had created all of those universes, rather than just a gateway to them. {{Word of God}} {{Hand Wave}}d this by saying that the cowboy universe was really the only parallel universe and the others were ''[[{{Pun}} perpendicular]]'' universes.
** Bender has mentioned being able to remember his own "birth." In season 6, it is revealed that Bender does not remember who was the inspector who approved him on the assembly line, and spends the episode trying to find out.
** Versions of his Birth are also pending to changes. In the episode where he recounts his birth, it was shown that he was built the way he was at that moment in a robot factory in Mexico. In another episode, where the cast turns into babies, Bender slowly de-upgrades along with everyone else, shrinking with each successive step just like everyone else. On top of that, he mentions he's only 5 years old, yet shrinks with everyone else in the aforementioned episode. If he really was 5 years old, he would have disappeared in the goo and never came out (since everyone gets around half a decade younger almost instantly), much like one of the buds on Zoidberg's body. Further muddying things is that Bender's head is over a thousand years old at this point, having spent centuries buried after the events of ''Roswell That Ends Well''.
** In the season 6 episode "Lethal Inspection", Bender discovers that he was built without a backup unit that would download a copy of his programming (i.e., his "soul") onto another robot body. Yet on the later episode "Ghost in the Machines", Bender dies and becomes a ghost, able to possess any machine.
*** He ''did'' [[DealWithTheDevil make a deal with the Robot Devil]] in that episode, though. At the very least, it's a HandWave as to why he was able to die and come back that time.
** Also in "Ghost in the Machines" we meet Robot God. This does not contradict anything in the series but it does contradict several audio-commentaries on past seasons where Matt Groening and the writers repeatedly stated that there is no Robot God.
* ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy''
** Grim becomes the Grim Reaper on at least three separate occasions. To list them: When his parents told him it was his "destiny" as a child and forced him into it, despite his desire to sing; found out his true calling, also as a child, but kept up the image of being a country rocker for over a millenia to please his father, and got the 'once in an eternity' school election to be one, competing with [[HarmlessVillain The Boogey Man]] and [[BigBad his]] [[RememberTheNewGuy old]] [[ChildhoodFriends Childhood Friend]] [[DemonicSpiders from]] ''[[TheMovie Wrath of the Spider Queen]]''. The probably only concrete thing about his reaping origins (at least in two of them) is that he started doing it as early as cavemen and/or dinosaurs.
** In the pilot episode, "Meet the Reaper", Grim came for Billy's hamster because the hamster turned 10. In "Billy and Mandy Begins", Mandy says that the hamster was 8 when Grim came for it.
* The ''WesternAnimation/TotalDrama'' series has this fairly often.
** One episode, for example, claims that Lindsay has very large feet ([[InformedAttribute that we never see]]) when she takes off her (apparently very tight) boot. However, we see her barefoot in the TDI Playa des Losers episode, and it's as small as you would expect it to be.
** During the TDI special, Chris says that Owen is the youngest of three brothers. In ''Action,'' Owen gives anecdotes about his two ''younger'' brothers.
*** Also according the special, Katie and Sadie never realized they were on TV through the whole first season and didn't seem to want to be on TV, even though they sent in an audition tape.
** A lot of information about the characters comes from [[AllThereInTheManual their online bios]], but the show seems to contradict them fairly often. Similar to Owen, Geoff's bio says that he's the oldest of five brothers, while on the show he once mentions having at least one older brother. Trent's father is supposedly an accountant, but on the show he says he's a lawyer ([[WildMassGuessing maybe]] [[UnreliableNarrator he was lying]] to avoid eating that garbage?) There are at least hints of this in other places, like Harold supposedly having an older brother and a younger sister, but alluding to his sister as having psychology books as if she were in college.
** In the spinoff ''WesternAnimation/TotalDramaPresentsTheRidonculousRace'' [[spoiler: Owen remarks that he wasn't upset about being eliminated as he had already won a million dollars. He actually only won a hundred thousand dollars in Island which he forfeited by accepting Chris' million dollar scavenger hunt.]]
* ''WesternAnimation/{{SpongeBob SquarePants}}''
** An episode has Patrick being visited by his sister, Sam. The problem with this is that he said back in season 2's "Something Smells" that he did ''not'' have a sister. Then again, [[TheDitz this is Patrick we're talking about...]]
** The episode where Squidward becomes nice has [[BrokenStreak Squidward actually beating [=SpongeBob=] for Employee of the Month at the Krusty Krab]]. The problem with this is that, in ''WesternAnimation/TheSpongebobSquarepantsMovie'' (which is the chronological series finale [[WordOfGod according to the creator]]), [=SpongeBob=] says he has won that award 374 times in a row. Note that winning employee of the month that many times (let alone in a row) means he's been working at the Krusty Krab for a minimum of 31 years and a bit.
* In the Disney animated series ''WesternAnimation/{{Hercules}}'', Hercules and Hades always run into each other every other episode, despite the fact that in the film this series is based off of, Hades isn't even supposed to realize Hercules was still alive until the latter is an adult. While a continuity error, this actually makes more sense than the movie due to the plot hole that goes along with it... how on Earth could ''the lord of the dead'' '''not''' be aware that Hercules ''wasn't dead''?
* Similar to the ''[=SpongeBob=]'' example above, ''WesternAnimation/TheFairlyOddParents'' episode "Double-Oh-Schnozmo!" introduces Cosmo's [[LongLostUncleAesop brother Schnozmo]], despite that the earlier episode "The Gland Plan" said that Cosmo didn't have any siblings.
* ''WesternAnimation/AmericanDad'' now has [[SeriesContinuityError/AmericanDad its own page.]]

* ''WesternAnimation/FamilyGuy''
** An early episode contains a flashback to when Stewie was younger and he had a normal-shaped head. He was jumping on the bed, smacked his head into the ceiling, and squished it into its trademark football shape. In another episode there's a flashback to when Stewie was born and he already had the football head.
** There's another episode via flashback that shows Peter, Cleveland, and Quagmire grew up together in high school, yet another episode later on shows Peter meeting Quagmire and Cleveland for the first time in their adult lives, and another episode after that shows that Quagmire is at least 15 or 20 years older than the rest of the group. Even more confusing, ''WesternAnimation/TheClevelandShow'' depicts on more than one occasion that Cleveland attended high school in Stoolbend, not Quahog.
* ''WesternAnimation/PoundPuppies2010'': In the episode "A Nightmare On Pound Street", the Mayor adopts a dog for his kids, remarking that the [[UglyCute "cute ugly"]] dog [=McLeish=] "gave" them reminded him of one he had as a child. In "Squawk", the Mayor says he needs a pet to give him an advantage with the animal lovers of the city, and, after [=McLeish=] asking if he wants to adopt a dog, brings out a parrot. The Mayor later reveals he only adopted the parrot to harbor votes, ''doesn't really like animals, and calls pets and animals in general "dumb"''.
* In the Season 1 episode of ''WesternAnimation/PeterPanAndThePirates'' "Slightly In Stone" the gang finds Captain Hook's severed skeletal hand clutching his sword in the crocodile's cave, however in the Season 2 episode "First Encounter" Peter took Hook's sword from him to cut off his hand.
* ''Series/CodeLyokoEvolution'' has some with its mother series, ''WesternAnimation/CodeLyoko'':
** While the character's abilities to deactivate towers is new, their ability to enter towers is played as a brand new development. In the original series, all of the characters were shown entering and exiting towers as the plot demanded it. While this could be passed off as them being unable to enter activated towers before, this was never shown and is a stretch.
** Additionally, in ''Evolution'', Odd quips that he has only piloted the ''[[CoolShip Skidbladnir]]'' once, while in ''Code Lyoko'' season 4 he pilots the ''Skid'' twice.
** Also in the original Code Lyoko, during "A Fine Mess" Odd and Yumi swap bodies and Odd claims he doesn't know how to eat with chopsticks and has to resort to using a plastic fork however only a few episodes earlier, Odd was depicted eating with chopsticks perfectly quite clearly.
** Similarly, in one episode William saves Ulrich from drowning in the gym's pool, naturally doing so by swimming. In a later episode, he panics when he's about to fall into a river because he "can't swim".
* In ''WesternAnimation/TheRaccoons'', certain episodes (especially "Making the Grade") depict the raccoons and Cedric all knowing each other since grade school. However, in "The Sky's the Limit," Ralph and Melissa's first meeting is explained, and presumably took place (over a spilled cup of coffee) when they were adults. Furthermore, the raccoons don't act like Cedric's an old friend in ''WesternAnimation/TheChristmasRaccoons''.\\\
The former might be passable if you reason that everybody did know everyone when they were children, but went their separate ways after school. The coffee story could be talking about how Ralph and Melissa met up again as adults. And since TCR was "just a dream," well, maybe Schaeffer just has a bad habit of dreaming his friends in random stories where they don't know each other.
* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'':
** In the first episode, when Nightmare Moon escapes from her 1000 year imprisonment and reveals herself, nobody in Ponyville knows who she is except for Twilight Sparkle, who read about her in history and myth books. Later, the episode "Luna Eclipsed" establishes a holiday called Nightmare Night (similar to Halloween) that has been around ever since Nightmare Moon was first imprisoned and was created in her honor. Ponyville also has a huge statue of Nightmare Moon.
*** They probably don't know what she looked like because 1: Parts of a story get changed as it is retold over and over again, i.e. Santa Claus. 2: That statue wasn't in Ponyville, it was in the [[http://i.imgur.com/oOhQqYw.png Everfree Forest]].
** In "Winter Wrap Up", Twilight Sparkle says Ponyville has been around for hundreds of years. In "Family Appreciation Day", Ponyville was founded by Granny Smith's parents when she was a child, making it less than a hundred years old.
*** It's possible the ponies have a long-ass life span, like say, the [[http://www.iol.co.za/dailynews/news/the-warty-oreo-dory-lives-to-over-200-years-1.1784161 Marty Oreo fish.]]
** In the Season 4 episode "Pinkie Pride", Mr. and Mrs. Cake mention the foal shower Pinkie threw before Pound and Pumpkin were born, implying that she knew they were going to have twins. In the beginning of the Season 2 episode "Baby Cakes", Pinkie and the rest of the Mane Six didn't know the Cakes were having twins until the day they were born.
* The 2006 ''WesternAnimation/BikerMiceFromMars'' series was meant to be a SequelSeries to the original 1993 show, but Vinnie is depicted in some episodes as liking pizza even though the original series established that the Biker Mice '''hate''' cheese.
* ''WesternAnimation/SagwaTheChineseSiameseCat'' has two in the episode "Sagwa's Lucky Bat". The first is that they are just discovering the clubhouse despite it appearing and being mentioned earlier. The second is that a flashback in the episode shows Sheegwa was around and old enough to talk in full sentences before Sagwa got her ink markings, despite the first episode implying the incident took place before or directly after her birth (the episode itself is rather conflicting about which).
* The 2009 version of ''WesternAnimation/RainbowBrite'' has Wisp returning to Earth to be with her family. The problem is Wisp is ConvenientlyAnOrphan and showed no signs previously of having any extended, adopted, or fostered family.
* ''[[WesternAnimation/BatmanTheAnimatedSeries Batman]]'' makes a comment that electricity has no effect on Clayface. Later in ''The New Batman Adventures'' and ''WesternAnimation/JusticeLeague'', Clayface is easily disabled by electric attacks.
* ''WesternAnimation/TheLegendOfKorra'': In season 3, metalbenders (a Red Lotus mook and Suyin) are able to bend liquid metal when Metalbending is actually achieved by moving chunks of earth trapped inside solid metal, causing the metal to bend and warp into the desired shape, which would obviously be impossible for a liquid, even if we were to accept that solid bits of earth were somehow safely forced into and subsequently pulled out of Korra's bloodstream.

* On ''WesternAnimation/WildAnimalBabyExplorers'', in "In the Swim," the Explorers don't recognize tadpoles and don't know that they grow into frogs. However, they learned all about this just a few episodes before in "Big Change." Additionally, in "The Name Game," the Explorers are asked to identify a seahorse by comparing it with a picture of a horse. They, however, had seen seahorses in at least one previous episode, so it should be immediately recognizable to them anyway.

** In a flashback of Arthur's Baby, a baby Mr Ratburn is called Emil by his mother while he scrawls multiplication sums on the wall. However, in future names, his first name is said to be Nigel.

** Not only that, but the episode "Have Yourself a Goofy Christmas" ("A Very Goofy Christmas") from the movie "Mickey's Once Upon A Christmas", which is said to chronologically precede the cartoon series, while featuring Goofy, Max and Pete as next-door neighbours, they live in two very different houses in a very different suburb than the houses and suburb featured in the series or in the movie(both the series and the movie feature different houses and suburb). And Max appears to be 5 years old at the time and Pete's wife and kids are nowhere to be found. And nothing implies Pete has a wife and kids, which he ought to have. One has to wonder how Goofy and Max ended up living from a suburban house to a trailer and then back to a suburban house again.

** While discussing a possible traitor in the ranks, Jean Grey says that it could be her, and asks Comicbook/{{Cyclops}} if he's forgotten about her unspecified "bad moments." This was presumably referencing ''Comicbook/TheDarkPhoenixSaga'', a storyline that wouldn't be adapted until the third season.

* On ''WesternAnimation/WildAnimalBabyExplorers'', in "In the Swim," the Explorers don't recognize tadpoles and don't know that they grow into frogs. However, they learned all about this just a few episodes before in "Big Change."

** In the Season 6 episode "[[Recap/MyLittlePonyFriendshipIsMagicS6E9TheFaultInOurCutieMarks The Fault in Our Cutie Marks]]", it's made very clear that ponies are the only creatures with naturally occurring cutie marks, even though it's been stated in various sources before that zebras also have them. In fact, zebra character Zecora shows up in that episode, cutie mark and all.

* ''WesternAnimation/AmericanDad'' now has [[SeriesContinuityError/AmericanDad it's own page.]]

* Happens a lot on ''WesternAnimation/AmericanDad''. They originally could've been excused as RuleOfFunny, but now borders on TheyJustDidntCare in terms of how frequent and contradicting they are.
** In "42-Year-Old Virgin", Stan claims to have never killed anyone, but he broke Jay Leno's neck on "Stan of Arabia, part I", killed his co-worker's double at the beginning of "It's Good to Be Queen", accidentally disintegrated one of his other co-workers in "I Can't Stan You", shot down a hang glider in "An Apocalypse to Remember," and shot a painter in "Con Heir."
** However, the episode "Haylias" ends with Stan suffering from evident selective memory loss following his battle with the BrainwashedAndCrazy Hayley, which could explain his assertion that he has never killed anyone as "Haylias" aired on American TV before "The 42-Year-Old Virgin."
** Another possibility is that Stan has never killed anyone he was assigned to kill, since all of the murders he committed were accidental.
** The first season develops Roger's experience with the outside world and learning to use disguise, but later episodes (particularly "Weiner of Our Discontent" and the first Christmas episode in which Stan goes back in time to kill Jane Fonda to rid the world of the wave of political correctness that has ruined Christmas) show that Roger has been disguising himself and living among humans since the 1950s (he protested against the integration of a Southern college in the 1960s by knocking the schoolbooks out of a black girl's hand, popularized disco in the 1970s, auditioned for the role of [[Series/SmallWonder Vicki the robot]] in 1984, and was the contributing factor to Joseph Hazelwood crashing the ''Exxon Valdez'' and causing that oil spill in 1989, Biggie Smalls getting shot and killed in 1997, and George Lucas introducing the world to Jar Jar Binks near the end of the 20th century), perhaps even longer, since one episode revealed that Roger knew Stockard Channing in the 1940s when she was 50 (even though Stockard Channing was born in 1944).
** In "Of Ice and Men", Roger doesn't know what happened to Stan's skating partner, though "Roger 'N Me" shows that Roger probed Stan and now has all of his memories. Either the writers forgot about that part or Roger just doesn't care about anyone who's not him (which is par for his character).
** In the pilot episode, Roger (after getting sneezed on) sarcastically says he's supposed to bring pneumonia back to his planet, but in the second episode, Roger claims that his species is immune to all human ailments (except for an unexplained cold sore). On top of that, "Weiner of Our Discontent" reveals that [[spoiler:Roger was the crash test dummy for a new model spaceship and intended to die upon impact, meaning that his planet doesn't want him back. It could be explained that his planet was just lying to him so he would get in the ship,]] but that just brings up another plot hole because Roger clearly said that [[spoiler: he was "sent" to decide the fate of humanity.]]
** In "Of Ice and Men," Toshi (the Japanese kid) marries Svetlana the Russian bride, but an earlier episode revealed that Toshi isn't worried about getting girls to like him as he has a girl arranged to be married to him back in Japan. Then again, the Russian bride's [[WhatHappenedToTheMouse mysterious disappearance]] after the episode could be the writers remembering that (or just making it so that way Toshi is as much of a loser with girls as Snot, Steve, and Barry are) and [[{{Retcon}} correcting the mistake]].
*** They actually were planning a subplot that would bring us his marriage again by having Steve, Snot, and Barry giving Toshi his very own bachelor's party. The idea was eventually scrapped.
*** Svetlana would be indirectly referred to again in Season 4's "Escape from Pearl Bailey" when Toshi remembers having a wife for awhile.
** In "Brains, Brains, and Automobiles," Francine teaches Roger how to use the vacuum cleaner, even though Roger had used one before in "Not Particularly Desperate Housewives" (even though the vacuum was rigged to explode by the Ladybugs). On top of that, Roger already knows how to clean a house (as seen in "Helping Handis").
** The episode "Chimdale" reveals that [[spoiler:Stan went bald after being the guinea pig for an acne medication which has the side effect of hair loss while he was in college and now has to wear a wig]], but a lot of earlier episodes have shown that [[spoiler:Stan's hair is real. In "Frannie 911," one of the flashbacks of Francine enabling Roger's behavior includes Roger [dressed as an American Indian] scalping Stan and Stan shown with stubble where his hair used to be. If Stan were bald from college into his mid-adult years and has to wear a wig, Roger could have just taken the wig instead of scalping Stan. In turn, this is forgotten in "Old Stan of the Mountain", when Stan is cursed to age prematurely, and his hair gradually greys and falls out.]].
** In the season two episode "It's Good to Be Queen," it's revealed that Francine's favorite song is "Little Red Corvette" by Prince, but in the season one episode, "Francine's Flashback", Francine's favorite song is "The Greatest Love of All", by Whitney Houston (whom Stan personally brought over to sing to Francine in exchange for crack cocaine). It ''is'' possible that Francine can have two favorite songs, but for the purposes of continuity, the writers should have stuck with "The Greatest Love of All" as Francine's favorite song since that was revealed first.
*** On a similar note, Hayley's favorite song has changed between episodes as well. In Season 12's "Kiss Kiss, Cam Cam" she claims her favorite song is "Bathtub Gin" by Phish. But in Season 6's "Jenny Fromdabloc" it's said that her favorite song is "Gangsta's Paradise" by Coolio.
** In the episode "May the Best Stan Win," there is a tombstone that reveals that Stan was born in 1967 and Francine was born in 1971, making Stan four years older than Francine, but the season one episode where Hayley dates Stan's boss reveals that Francine is actually ten months younger than Stan. This also throws Francine's continuity out of whack, since it's been stated that she was a wild teenager in the 1980s. If Francine really was born in 1971, she would have been nine in 1980 and wouldn't reach teen age (13) until 1984 (even though the episode "Francine's Flashback" shows that Francine looked at least sixteen in the mid-1980s when she first met Stan).
** In the season two episode "Star Trek" (in which Steve becomes a children's book author), Steve is horrified and disgusted when he finds out that the centerfold model Stan promised him is an old woman (and that the picture of her when she was young was from 1957), but in season one's "Con Heir," Steve had no problem making out with and having a romantic relationship with an elderly woman at a nursing home. Then again, it's possible that he was just too disappointed to look over her age as the model used to be ''very'' attractive.
** In Season 11's "CIAPOW", Dick claims to have never seen ''Argo''. But in Season 4's "Stan Time" he mentions being in the process of watching every movie ever made thanks to the sleeping pills that prevented him from sleeping.
** In "Now and Gwen" from Season 11, it's revealed that while Francine was a freshmen in high school her adopted sister Gwen was a senior. Even though in Season 3's "Meter Made" it's said that Gwen is three years younger than Francine.
** Despite have a very ''It's a Wonderful Life''-esque fantasy in "Stan of Arabia - Part 2", Stan claims to have never seen the movie in "Dreaming of a White Porsche Christmas" from Season 11.
** Two for Season 11's "Morning Mimosa":
*** Steve is said to be 14 despite turning 15 in Season 7's "Virtual In-Stanity".
*** Snot is romantically interested in Hayley despite losing interest in her in Season 8's "The Missing Kink".
** Two for "My Affair Lady":
*** Hayley mentions being unemployed for five years even though she's been shown have numerous jobs before such as an airport attendant in "Minstrel Krampus" and as a bartender in Roger's bar in "She Swill Survive" (both episodes being from Season 9).
*** Klaus' human design seen in this episode is drastically different from the one shown in the pilot and Season 8's "Da Flippity Flop".
** Francine writes a mystery novel in "Manhattan Magical Murder Mystery Tour", even though she claims to hate reading in "Stan Time" from Season 4.
** In the Season 12 opener "Roots", Stan is shown riding a bike his tree in the flashback sequence even though Season 4's "Jack's Back" claims that he never learned how to ride a bike as a kid.
** Two for Season 12's "The Devil Wears a Lapel Pin":
*** Francine claims she never went to college, even though she mentions meeting Stan there in the pilot as well as mentioning how she stabbed her college roommate in Season 4's "Family Affair".
*** Apparently the Smiths live on 416 Cherry Street instead of 1024 Cherry Street.