Mood Whiplash/Western Animation

"Twilight: (dejected) I never thought it would happen. My friends...
 * Moral Orel, once a lighthearted farce of small-town America, eventually fully transformed into a dark character study of its characters' depressing lives. Which is made even worse with the occasional heartwarming episode. No one is sure if it'll end with them all killing themselves or finding some kind of redemption....
 * Teen Titans was fond of these, although fans eventually picked up that any Theme Tune switches meant the episode could be much darker.
 * On the flip side, if the intro song was in Japanese, that meant the episode would be wacky (featuring Mad Mod, Larry, etc.)
 * The "best" example of this would be when they aired prehaps the darkest episode in the series, involving the end of the world, a demon coming to conquear earth, a villian ressurected from hell, Raven being informed she's destined to end the world, and prehaps an implied rape. Then the next episode is about Beast boy working at a McDonalds like place, fighting evil Tofu.....
 * The dark Season Finales of 1, 2, 3, and 4 featured a very silly (involving the an alternate dimension) episode right before them.
 * In Season One, sandwiched between the first Red X  episode and the Apprentice Season Finale was ... Mad Mod trapping the Titans inside his school.
 * In Season Two, sandwiched in between  and when Terra   features Larry, a ridiculous dwarf version of Robin.
 * In Season Three, before the episode where Cyborg moves out of the Titans Tower to form Titans East with Aqualad, Bumblebee, Speedy, and Mas y Menos, we have Mumbo, who traps the Titans in his own hat, which is very ridiculous.
 * In Season Four, before the three part season finale featuring, we have Mother Mae Eye, whom is a witch who basically made everything the Titans see an acid trip through pie.
 * Season Five didn't really have any "silly" episodes before their Series Finale.
 * Avatar: The Last Airbender
 * An episode that reveals the largest city in the entire Earth Kingdom is ruled by a Government Conspiracy that has no intention of helping them win the war is followed with an episode about the various everyday activities of the characters in that same city.
 * And one of the shorts in that Day in The Life episode has Iroh cheerfully dancing and singing through the city on a shopping errand, with the short ending on him, still singing that happy song, breaking down sobbing over a small memorial shrine for his dead son; ending with a dedication to Iroh's deceased voice actor.
 * The whole Ba Sing Se arc has a lot of Mood Whiplash. Take the episode "Lake Laogai" -- has just been left for dead in the shadowy headquarters of the Dai Li in what many fans consider one of the darkest and saddest moments of the season, if not the whole series. What follows immediately after? The triumphant return of, complete with uplifting music and a dramatic rescue; and a joyous, tearful reunion between Aang and his beloved companion. And   is never even mentioned again until the thrid season.
 * Season 3 has the ninth episode. It's a Breather Episode after one with a slight Downer Ending and before an event the show had been leading up to for a full 20 episodes. The episode also contains internal Mood Whiplash: Aang has some weird dreams, then a freakish and creepy one, then a bunch of crazy hallucinations!
 * The last episode before the Grand Finale is "The Ember Island Players"; a Breather Episode where the Gaang watch a (very poor) play based on their adventures. Most of it is hilarious Flanderization of the main cast, but during the intermission, it whiplashes when the Gaang considers the mistakes they've made and their regrets. Then it goes back up, and then, . After all, the play was.
 * From the first season, we have the episode "The Great Divide," which is widely despised by pretty much everyone for being typical kiddie TV fare. Light-hearted, non-serious tone... and then we get to the next episode, "The Storm," which leaves viewers going, "Uh, I think I just witnessed a thirteen-year-old boy getting his face burned off. By his father."
 * Mood Whiplash from the other end as well, as "The Great Divide" was preceded by "Jet", which involves the title character tricking the team to help him destroy a garrison of Fire Nation soldiers with a flood. Only problem? The garrison is in an Earth Kingdom village. Full of civilians. Which Jet chalks up to as "necessary sacrifices."
 * "The Chase." Starts with no one getting any sleep and yelling at each other and ends with
 * During the Grand Finale, there's a scene where Sokka uses an absolutely hilarious announcement over the intercom ("Everyone please proceed to the bomb bay for hot cakes and sweet cream. We have a very special birthday to celebrate!") to get the crew of the airship he and his friends are taking over out of the way. You know, the airship that's part of the fleet Fire Lord Ozai is using Oh. The best part? It's actually some guy's birthday.
 * Danny Phantom plays this trope like a harp.
 * Ben 10 Alien Force has a couple of episodes of this. The sixth episode, "Max Out", is very serious, with the kids discovering that the DNAliens are actually people infected by an alien xenocite and ends with . The seventh, "Pier Pressure", is very upbeat - it's about Ben's date with Julie, and is only minorly inconvenienced by the alien Ship's antics; there's no real villain. The eighth episode, "What Are Little Girls Made Of", is fairly serious, and gives a nod to the ending of episode six with Gwen moping a bit at the beginning. The sad thing is, by production numbers, "Pier Pressure" should have been aired sixth, and then "Max Out" seventh; as it is, Gwen spends an entire episode happily encouraging her cousin to ask his crush out, and then bantering with Kevin on why he's slow to ask her out, before suddenly snapping back into grief.
 * Garfield His 9 Lives goes from standard Garfield humour, to a surreal take on the Garden of Eden story, to a sad story about a pianist's first cat, to a nightmare inducing scenario involving a lab cat, to a tribute to Krazy Kat. And at the end Garfield meets God. If you think that's bad, try to find the graphic novel it was based on. Most of the stories made it into the animated special, but not the one that ends with Garfield, drawn as a realistic orange tabby that's either driven crazy by time travel or possessed by evil spirits, leaping with fangs bared and claws outstretched right into the face of his owner, an elderly woman. (Who's not even looking at him, and saying "come play with maw maw" right as he's pouncing.)
 * Transformers Animated does this a lot during the third season. The first two seasons were relatively light-hearted, with most every death being ambiguous. "Transwarped" rolls around and we have  Then it's on to "Three's A Crowd", featuring the wacky antics of Bulkhead and the Constructicons. Then it's on to "Five Servos of Doom" where
 * Speaking of Transformers and mood whiplash between sequels, Beast Wars, despite deep and emotional episodes such as "Code of Hero" and "Transmutate", was generally thought of as light-hearted and humorous. Its sequel series however, Beast Machines, was much darker with an entirely different tone, look, and feel. Even Simon Furmon commented on how dark it was. This led in part to fan backlash.
 * Speaking of "Code of Hero", we have Dinobot's last conversation where the Maximals are solemnly discussing Dinobot's sacrifice and Rattrap speaks up in a Call Back to a previous conversation they had that episode about where Dinobot stands. Still in pain, he says "upwind of you for preference", putting a smile on Rattrap's face, knowing his best friend won't let his imminent death stop their verbal sparring matches.
 * This happens a lot with the Bilingual Bonus substitution cipher that is cybertronix. For example, there is one passage in the Transformer equivalent of the bible, quoted in the dialogue as "And a great dragon was cast out onto the earth, and his followers with him", something treated with appropriate religious and prophetic weight. Translating the onscreen text, however, reveals that the sentence continued "two corks, one fork, and a bowl of beans between them".
 * Courage the Cowardly Dog, "Last of the Starmakers", that is all."
 * South Park
 * The show stuck to this trope since season 5, with episodes such as "Kenny Dies", "Raisins", and "Guitar Queer-O", dealing with the death of a friend, a painful break-up, and the drama between good friends respectively.
 * Most of the first half of season 15 was lighthearted goofiness, often showing how stupid various characters (or the South Park-verse's inhabitants as total) are. You're Getting Older is.
 * Futurama is notorious for sudden mood whiplashes, and for doing it numerous times within an episode, not just the show's infamous tear-jerker endings.
 * "The Sting" is probably the best example -- you could be severely depressed, sniffling, and in agonizing pain as a guilt-consumed Leela descends into madness, her hopes dashed for the THIRD time, yet laugh your ass off as her warped mind imagines the entire crew launching into a broadway-style musical number, complete with flashing lights, and then be knocked into a shivering, sobbing mess by the following scene.
 * The funeral scene is a perfect example of this: in a matter of seconds, we go from Leela's "Its All My Fault" response, the Professor denying this in an attempt to comfort her, to him loudly telling Bender "I'm lying to make her feel better!"
 * Let's not forget the episode with Fry's dog. The entire episode, you're built up to expect that he'll get his dog back, wacky hijinks ensue, and then Fry Good God, I'm tearing up right now. Damn you, Futurama!
 * Or the episode where Fry is weeping at the revelation of ... while in the background Bender collects enough skeletons for a Mousketeers reunion.
 * Justice League Unlimited does this on occasion
 * One notable example being the episode "Kid Stuff," which manages it with one line of dialog. After a relatively lighthearted adventure featuring magically pre-teen versions of Wonder Woman, Green Lantern, Superman, and Batman and drawing much humor from the fact that Kid!Batman's attitude hasn't changed a bit, Wonder Woman comments that it was nice being a kid again. Batman responds with, "I haven't been a kid since I was eight years old".
 * And it's followed almost immediately with the scene of Mordred, a shriveled old man, being taken care of by his mother. In contrast to how he was in the entire episode as a kid, it's kind of a shock.
 * Batman the Animated Series does this from time to time. Robin's constant puns and one-liners can be a bit distracting in serious fights or chases. It also may have been intentionally invoked with Baby Doll and her rapid switching back and forth between her real voice and her disgustingly cute persona.
 * The Oscar nominated film, Screen Play, starts out as a quiet romantic Japanese tale that seems to end happily, until a jilted character suddenly bursts into the stage and starts killing everyone in sight, starting with the narrator.
 * Disney's The Princess and The Frog is a thoroughly lighthearted return to the classic Disney form, albeit with a more humorous tone almost akin to Aladdin... that is, until
 * Disney does this with their take on The Hunchback of Notre Dame as well with the songs Heaven's Light and Hellfire. They're one piece back to back really. We go from Quasimodo singing about his love for Esmeralda and how lucky he is to even think he's got a shot to what is perhaps THE best Villain Song Disney's ever done. Now "A Guy Like You", the happy, bouncy tune, comes out of nowhere between two very dramatic scenes, the latter including Phoebus nearly dying and Quasi learning that Esmerelda loves him instead. All during the burning of Paris. Ow, my neck!
 * School House Rock's "The Tale of Mr. Morton" ends in a sweet but undeniably disorienting way, since it goes straight from Mr. Morton wallowing in despair over his inability to ask Pearl out to Pearl proposing to him (I'd pothole that to Fourth Date Marriage, but it's more like Zeroth Date Marriage) and the two of them living Happily Ever After. Even the music does a 180.
 * The first Star Wars Clone Wars show, when General Grievous kicks his way into the Chancellor's office to try and kidnap him. The Jedi rush the Chancellor out, leaving the clones behind to stall him in scenes of what is very nearly explicit carnage (only the lack of blood kept it from being truly horrific). Cut to the Jedi waiting for the elevator to arrive, with screams, blaster fire and chainsaw sounds coming from the office. And then one of the Jedi reaches out and pushes the elevator call button 6 times to make it get there faster.
 * Megas XLR begins with a Humongous Mecha space battle presented in the tried and true Space Opera style. This lasts for over seven minutes as female lead Kiva Andru runs off with the enemy's Super Prototype and tries to send it back in time a few years so it can change the desperate last stand in favor of humanity. The alien forces attack, and things go wrong. After the title and commercial break, cut to two Clerks-style slackers from New Jersey...
 * The Simpsons
 * Season 22 Episode 3's Couch Gag intro. It goes from the standard sequence, then becomes a meta reference to the show's animation process in South Korea, interpreted by graffiti artist Banksy as a sweatshop. Warning: High Octane Depression Fuel.
 * Homer does it to himself when in the video store, alternating between looking at two screens, one showing a comedy and the other a Tear Jerker.
 * The Ren and Stimpy Show was quite fond of this trope back in the day.
 * "The Cat That Laid The Golden Hairball", as the title would suggest, starts with a news announcement that hairballs became more valuable than gold. Knowing this, Ren used his feline companion Stimpy for making hairballs -- it goes fine up until he learns that Stimpy has overused his hairball gland. He, Stimpy and a Kowalski lookalike named Bubba all start tearing up. Out of nowhere, Ren and Stimpy state that it's over and start singing and dancing cheerfully while happy jazz music plays in the background.
 * "Man's Best Friend" starts out rather cheerfully with happy Raymond Scott-like music played in the background... and then very unexpectedly cuts into a loud dramatic sting and a sinister-looking "Starring George Liquor" card.
 * There's a literal in-universe example caused by a device called "the happy helmet". It's an invention of Stimpy's that can change moods from any sort of anger or sadness into absolute happiness with varying levels of intensivity.
 * "Sven Hoek" features Ren acting insanely angry when describing how he's going to hurt Sven and Stimpy before stating perfectly normally that he has to pee.
 * Family Guy
 * The two-parter where Stewie kills Lois. For the first 8 minutes, it's the usual post-cancellation FG humor, and then, Stewie sneaks aboard onto the cruise ship and shoots Lois, who appears to have died as Stewie intended, and fell from the ship into the ocean. Joe had to call off the 6-day search for her, and a year has passed since. Brian finds out that Stewie killed Lois, suspicion from Quagmire, Cleveland, and Joe falls on Peter when he recently takes a life-insurance policy on her, Stewie throws away his gun and drawing of himself killing Lois, and Peter's friends find the evidence and believe that Peter did it, leading to Peter's testimony in court. He was found guilty, but then, Lois shows up, alive, and tells everyone that Stewie killed her.
 * Part 2 reveals how Lois came back to Quahog. She was saved by a Merman, which isn't the kind of what you had in mind. Lois lost her memory and worked at a summer camp for fat kids, preventing them from eating each other. She then meets a man named Derek, who was a White Supremacist. At a meeting, Lois' opinion gets her a bottle to the head, restoring her memories. Stewie then holds his own family hostage, kills Cleveland, and forces Brian at gun point to do as he says and later on, drive him to the CIA, where a Crossover with American Dad ensues, and then Stewie becomes the tyrannical president of America, in which he makes up absurd laws (i.e. banning direct-to-video Disney sequels and throwing apples at Peter). Lois can't take it anymore and plans to take down Stewie on her own. As Lois and Stewie took each other on, the fight ends with Peter killing him, but luckily, it was all just a simulation.
 * Despite how dark the two-parter was, there were some funny stuff between all of the drama, even though most of the funny stuff were cutaway gags.
 * Re Boot had an episode with alternating scenes of Dot and Bob's wedding preparations and Glitch-Bob slowly dying in the Supercomputer. He got better, but then it got a LOT worse.
 * Animaniacs. It could go from a show in which cute cartoon characters run around eating sweets or singing nonsense songs to a show in which cute cartoon characters look for a home or get taken into care in THE SAME EPISODE. And it's AWESOME.
 * The theme song for the Hanna-Barbera The Godzilla Power Hour. It starts off big and epic, emphasizing how frightful a creature Godzilla is...and then they get to Godzooky.
 * Happens barely two minutes into the My Little Pony pilot. One moment the Ponies are frolicking around, being Moe Moe and all other sorts of unimaginable adorable, and then demonic dragons come flying out of the sky complete with a thunder storm and kidnap several of the ponies to become slaves.. Yup. It happens a few other times in the pilot, too; One moment they're singing, and the next, something horrific happens.
 * The first My Little Pony special featured killer dragons, an Omnicidal Maniac villain and very little fluff, and was mostly action based. The next special is considerably more sweet--though still dark.
 * Happens somewhat frequently in My Little Pony Friendship Is Magic:
 * The series premiere ends with a cliffhanger as the Big Bad brings about eternal night, then suddenly the happy ending tune kicks in.
 * Done again in season 2's premiere. And again in Season 2's finale. At this point its pretty much an unintentional Running Gag for the first part of a two parter to have a Downer Ending, only to transition into the show's happy theme song.
 * Done in-story when Twilight Sparkle realizes her "friends" aren't interested in helping her stop the Big Bad.

(pause)

Twilight: (angry) ...have turned into COMPLETE JERKS!"

"Ice King: (sobbing) Now you know my secret..."
 * The third act of "Stare Master" goes from a group of kids playing around in the woods to discovering the petrified body of one of the mane characters.
 * In "Owl's Well That Ends Well", the transition from Twilight gently praising Spike as he sleeps to angrily confronting him about her burnt astronomy book is very sudden and shocking.
 * The song "Becoming Popular (The Pony Everypony Should Know)" from the episode Sweet and Elite is a very upbeat tune about Rarity's happiness at being accepted into high society...until the last bit, when it suddenly turns very somber and somewhat saddening as she realises she is just too exhausted to complete her friend's birthday dress in time.
 * The episode "Baby Cakes". One somewhat short scene in the second half of it could be considered a shout out to horror movies in general, what with creepy children laughter and SOMETHING CRAWLING ON THE CEILING! Oh, did I mention the plot is Pinkie Pie babysitting children?
 * A cartoon simply called The Snow Man (no, not that one) starts out with sickeningly sweet Disneyesque cheeriness and dancing.
 * Adventure Time
 * The episode "Holly Jolly Secrets". For the most part, it's a holiday episode where Finn and Jake find some of the Ice King's abandoned video tapes and decide to decipher them for "evil secrets". Many of the tapes are of the Ice King playing with his penguins, attempting to work out, and making fake news interviews with captured princesses. Then, when the Ice King barges in to reclaim his tapes, Finn quickly puts the last video in. Finn and Jake's reactions are the same as the audience's.


 * A less extreme version, and YMMV, but the "Little Ghost Pranksters" scene in Too Young. Some fans found the scene hilarious. In summary, Finn and PB dress as Bedsheet Ghosts to make Lemongrab leave. They approach him, waving their arms and making ghostly noises... and punch him in the stomach, push him onto the floor and run away laughing. The mood whiplash, for some fans, starts right when Lemongrab actually starts crying, and it's a very pitiable, soft whimpering; not the typical screeching or screaming we hear from this character. But whether the scene is sad or hilarious is up to interpretation.
 * Codename Kids Next Door does this quite a lot, especially in later seasons.
 * Mood whiplash occasionally happens in Wakfu. The biggest offender would have to be the 15th episode of season one. We close on "à suivre" (French for "to be continued"), our heroes apparently engulfed in a dragon's fire breath. Then we get the episode's Couch Gag, and a silly little drum ditty the gang plays on a barrel to try to wake Ruel inside.