"You know, I can't help but notice you seem a little at war with yourself here."A character whose personality isn't marked by any set mood, but by their tendency to swing between moods drastically. Sometimes (if the characters around them are lucky) there's some sort of warning of an impending mood swing — or at least a recognizable cause — but there may just as easily be no warning whatsoever. Frequently this is combined with emotional lability, so they skip any emotion that isn't extreme. They're never just happy, they're the cheeriest Genki Girl in the world. They're never just sad; they're on the verge of suicide. They're never just angry; they're filled with Unstoppable Rage. And they can flip between any of them at a moment's notice. May very well be a one-person Four-Temperament Ensemble or red and blue oni. Though they may be referred to as "bipolar", their mood swings are generally much more abrupt and frequent than the periods of mania or depression associated with real-life bipolar disorder. This can, however, be a facet of borderline personality disorder. We have our own Useful Notes on Bipolar Disorder as well. This is a stereotypical trait of women who are currently menstruating or suffering from PMS. It is Truth in Television, and fairly common at that, but not typically as extreme as fiction portrays it to be nor as universal. Also, not every woman whose mood is affected by menstrual hormones will be susceptible to every mood; some get stuck swinging into one mood and temporarily become a Fragile Flower or acquire a Hair-Trigger Temper. Since the same hormones are involved, pregnant women are also known for being Mood Swingers. The Mood Swinger as a Love Interest frequently fills the role of the Tsundere. This is also a common trait of The Caligula. For even more extreme cases, see Hair-Trigger Temper, Split Personality, Jekyll & Hyde, Tsundere and Yandere. Not to be confused with Mood Whiplash, which is a trait of the storytelling, not an individual character.
—Flynn Rider, in response to the page image
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Anime and Manga
- Alois Trancy of Black Butler. Throughout the first episode he switches from cute and innocent to Ax-Crazy so many times it could make someone dizzy.
- A rather dark example, since Alois's mood swings tend to be severe Mood Whiplash as well - going from cute and entertaining to Troubling Unchildlike Behavior with ridiculous speed, and then back again. Not to mention that his extremes can create gems like the time he stopped innocently eating breakfast to gauge his fingers through a maid's eye and then wiped his hand and went back to his eggs.
- Revy of Black Lagoon normally displays a wide range of emotions, all the way from affection to psychotic rage to calm boredom.
- Kagura from Fruits Basket. She seems cute at first, but whenever Kyo's around she becomes a combination of a Yandere and a Tsundere.
- In the beginning at least, Kyo came across as this since he had No Social Skills and had a tendency to snap at people he wasn't mad at. So he'd yell at someone, apologize, then yell at them for not understanding him. Then apologize...
- Mobile Suit Gundam 00: Allelujah in the movie, leaving some questions to how the Split Personality thing is going since he's Out of Focus.
- Haruhi Suzumiya comes close. Now she's a cheerful Genki Girl, the next scene she's abrasive, confrontational, dominant and almost narcissistic, after that she may become extremely melancholic. There are reasons for her mood-changes, but sometimes it just appears randomly.
- Rena from Higurashi: When They Cry. This and the fact that she's a Nightmare Fetishist seems innocent enough at first, but then you find out she's a Grotesque Cute Yandere antagonist best known as the "Cleaver Girl" for her Ax-Crazy tendencies. Sometimes. The games hint she has a bipolar disorder, but it's exaggerated so it seems freakier.
- Misao Mikogami from Kami Kaze can be a fairly cheerful and fun-loving teenage girl, nice to anyone who needs a hand, and will stand up for someone when they need it. Say the wrong thing around her and her mood will change so fast that you won't even have the time to mouth the words Oh Crap! before you're standing under an ocean of water with your current surroundings gone so far beyond the Godzilla Threshold that you'll be glad you're not around to see the aftermath. And that's not counting the times you've pissed her off enough that she decides to play around with you for a little while. She's the nicest deity in this series.note .
- Ayukawa Madoka from Kimagure Orange Road is pretty bad about this, though her swings are more day to day than moment to moment. And of course she's the Tsundere leg of the Love Triangle.
- Yuno of Future Diary often can go from a sweet, lovable and huggable darling to a murderous and terrifying psychopath on a whimnote , and usually in the span of a single episode. Most of the time, all it takes is either threatening or flirting with Yukiteru.
- Karin from Naruto. Karin has a fluctuating personality, at times appearing stern and tough and Tsundere and other times appearing carefree and highly flirtatious, but only around Sasuke.
- King Hamdo from Now and Then, Here and There takes this trope to terrifying extents. His moods usually switch from petty, to cruel, to violently moody, to pathetic, and back, usually over the course of a few minutes.
- Harry of Outlaw Star.
- A good deal of the characters from Sayonara, Zetsubou-Sensei. Namely Kafuka who's somewhat similar to Rena, except she's even more overly optimistic.
- Kamille in Mobile Suit Zeta Gundam can go from personable and friendly to teenage angst-fest in the blink of an eye (Not Hyperbole). It's oftentimes difficult to tell what exactly set him off.
- Naomi in Zettai Karen Children started off being the calm, sweet girl all the time. Once she realized that her supervisor Tanizaki's treatment of her was why she was having trouble with her powers, she lets loose and from then on shows no restraint in throwing him into a wall when he gets too close. Her Code Name even changes from "Kitty Cat" to "Wild Cat" in the process.
- ACDC from Jojos Bizarre Adventure, even admitting that he's the most emotional of the Pillar Men. When Joseph cuts off his arm and destroys it so he can't reattach it, his reaction is to...burst into tears and cry like a little girl, and then after a while stop as quickly as he started and claim he was just blowing off steam. This actually makes him dangerous; Joseph reads his opponents to get the upper hand on them, but it's impossible to read ACDC's constant mood shifts.
- Upotte: Agu (a personification of the Steyr AUG) switches from a shy assault rifle to an overbearing squad automatic weapon with a change of barrel/hairstyle.
- Magical Record Lyrical Nanoha Force has Curren Hückbein and Cypha. Cypha is The Stoic, but she often switch to her sadistic Ax-Crazy persona when she's in a battle. The Big Bad Curren can be very childish, acts as cute and sweet woman, only to switch to her dark, intimidating and creepy persona, then back and forth.
- A Crown Of Stars: During her first day in Avalon Asuka’s mood is changing constantly from bitter and weary to smirking and bubbling to angry to serious. Shinji notes that her moods are changing very quickly and he does not know how adapting.
- Calvin and Hobbes III: Double Trouble gives us the Mood Swing Babbler, an alien from Planet Zok
- Evangelion 303: Due to her psychological trauma, Asuka's mood could change very, very quickly. She could go from cheerfulness to aggressiveness, restrained calm to unbridled anger, fury to depression or despair to happiness. It could become pretty disconcerting when people met her for first time.
- Scar Tissue:
- After Instrumentality, Shinji's mood could change abruptly and instantly when he was pushed the wrong way. He could go from quiet to maddened berserker to depressed to happy to sad in a matter of seconds.
- Ironically, Asuka's mood stopped being so shifty. After Third Impact she was nearly permanently angry and paranoid. During the fic she makes an effort to control her temper, and she is constantly gloomy and depressed.
- Sollux is this in canon, but even more so in the fanadventure Be the Sea Dweller Lowblood. He and Karkat will get in a fight, one of them will apologize, the other won't accept, then the second one apologizes and the first one ignores him, they get into another fight, one of them will apologize but be rejected again, one will think about apologizing but change his mind, one will beat himself up over not apologizing sooner but then not go through with it, etc, etc, etc.
Congratulations. Over the span of two minutes, you succeed in getting pissed at Karkat, forgiving him, and getting pissed at him again, despite the fact that you have neither spoken to him nor physically seen him for hours.This is not bipolarity. Bipolarity is a pendulum swinging back and forth, going tick-tock like the beat of a heart, sometimes slowing so that it will be days before the next tick, perigees before the next tock. Sometimes for a time, it freezes in the middle, and you can breathe easy and clear your head. The emotions are not nearly as neat and tidy as a pendulum, but the process, the process is.This is not bipolarity.This is insanity. Not the tick-tock of a pendulum but the tacktacktack of a pinball machine. The swings are jagged and irregular, not back and forth but lurching all over creation. You're lucky when you get to hold on to an emotion for more than a fleeting moment.You haven't been "bipolar" in sweeps. You miss being bipolar. It was better than this unidentifiable monstrosity.No it wasn't! Ha ha ha, what are you talking about? It was even MORE horrible compared to this! At least this way you're guaranteed to not have to put up with a bad mood very long.... Except that you usually switch from one bad mood to another bad mood.
- In Mega Man Reawakened, Tron Bonne has been like this since Arc 5 began—and it's revealed it's because she's pregnant.
Film - Animated
- Boingo from Hoodwinked acts like this once he drops his Tastes Like Diabetes facade and starts acting like a supervillain. The commentary remarks that on one occasion they couldn't decide which take to use (maniacal, verge of tears, etc), so they just decided to string them all together to very good effect.
- After escaping from the tower in which she's lived her whole life without leaving in Tangled, Rapunzel swerves wildly between unrestrained joy at being liberated and crushing guilt at breaking the promise she made to Mother Gothel to never leave the tower.
[ecstatic] I can't believe I did this!
[horrified] I can't believe I did this.
[overjoyed] I can't believe I did this!
[appalled] Mother would be so furious.
[sitting by pond] But that's okay, I mean, what she doesn't know won't kill her, right?
[sitting in cave] Oh my gosh. This would kill her!
[running through leaves] This is sooo funnnn!!
[leaning on tree] I am a horrible daughter. I'm going back!
[rolling down hill] I am never going back!
[facedown in meadow] I am a despicable human being.
[swinging from tree] WOO-HOOOO!! Best! Day! Ever!
[sitting by rock] *sobbing*
- "Let It Go" from Frozen is emotionally deep and complicated (part of what may have contributed to its Oscar win), and during some of its most intricate moments Elsa wears many highly expressive faces that change nearly second by second. It almost seems like Elsa has mixed emotions. At points, she has the facial expression of outright anger (for instance, when she casts off the gloves and cape), mixed emotions (when she creates Olaf), and outright happiness (when Elsa conjures up the icy staircase to bridge the chasm). And there are lines like "I'm never going back, the past is in the past!" where Elsa really rapidly changes facial expressions: from distress, to resolve, to sorrow, to resolve, to anger, to relief and happiness, regret, and then, as she's about to let down her hair, you see a pained look on her mouth like someone just punched her in the face.
- Basil from The Great Mouse Detective certainly swings from manically happy to crushingly depressed and back to manically happy again quickly. Of course, this is because he's based on Sherlock Holmes, who was possibly bipolar, and definitely a massive cocaine addict. So either Basil could use a little lithium, or he's gotten into a bad, mouse-sized vial of seven per cent solution (an expected hazard of living under Holmes' floor).
- The Nightmare Before Christmas: Jack Skellington, particularly during his BSOD Song, "Poor Jack".
- The Mayor of Halloweentown, to the point of literally having 2 different faces.
- Wreck-It Ralph: King Candy is known to switch emotions wildly several times within the same sentence - from cheerful giggling, to flustered, to angry, to some more giggling. He can be making puns one second and furiously ordering around his guards in the next. Even when he briefly drops the King Candy image and shows himself as Turbo, he can't help but snap to gleeful conceit in-between his fury at his plans being unraveled.
Film - Live Action
- Paul, later in Pain and Gain, due the effects of cocaine (as pointed out by the Fun with Subtitles). He zig-zags between cheerful, remorseful and stoic.
- Multiple characters in The Room, but Johnny most obviously. He (in)famously goes from a tirade about how his "future wife" has falsely accused him of domestic abuse to being happy to see his best friend.
- The titular character in Julien Donkey-Boy, being a Paranoid Schizophrenic. His eccentric Father (Played by Werner Herzog) also counts, both in a very disturbing manner.
- Gary King in The World's End is this, quickly able to shift from sad and regretful, to serious, to excited and manic (his most common phase). This is an early hint that all is not right in his head, and he uses his tendencies to help mask some of his deceptions from his friends.
- Vlad Tepes in Count and Countess, usually to scary degrees.
- Tonker in Monstrous Regiment has only two moods: calm and berserk. The description used in the book is "has no middle gears."
- Peter Pan: This is Tinker Bell's original characterization. J.M. Barrie explains that fairies are 'so small they only have room for one feeling at a time.'
"Now, Tinker Bell was not all bad. At least, she was not all bad all the time."
- Hell, Peter's like this at least as much. Having been raised by fairies may have something to do with it.
- Less than halfway through the first novel, it's easy to see where theories of Sherlock Holmes being bipolar come from.
- Edward Cullen of Twilight fame is a rather offputting example. He's portrayed as a tortured, yet romantic gentleman who has the utmost devotion to Bella...but only when she's submissive. However, when she puts up even the slightest resistance or actually voices complaints, he quickly goes from a "sensitive" boyfriend to a frothing, rageful lunatic bent on putting her in her place. In addition to his manipulative tendencies, it is because of this that he serves as the perfect candidate for a walking PSA and redflag archive on Domestic Abuse.
- Anakin Skywalker isn't too different. His frustrations with the war, the Jedi, what he feels is a lack of respect from said Jedi, and his fears about Padmé's prophesised death mean conversations with him are a veritable minefield. Even Padmé herself isn't safe as the story goes on. Just mentioning she's been talking to a group of senators who aren't happy about the way the war is going is enough to get Anakin to act increasingly hostile. And that's before his Face-Heel Turn.
Live Action TV
- The wife of the man with the bazooka round in his chest in the bomb squad episode of Grey's Anatomy. She goes from uncontrollable screaming to uncontrollable tears to uncontrollable rage and then back to uncontrollable tears.
- An eighth season episode of Law & Order has McCoy and Ross prosecuting a manic-depressive teenager whose wealthy grandfather is hindering the case. The grandfather abruptly launches into a paranoid rant cutside the courthouse, tipping off McCoy to his own manic-depression and giving him an opening to press a better deal for his grandson.
- Kevin the Teenager from Harry Enfield and Chums is a nightmarish example.
- Muppets Tonight director Nigel suffers from this, going from mellow to hysterical and back again at the drop of a hat. Though working with The Muppets can have that affect on people.
- Sherlock's Jim Moriarty has, to say the least, a habit of doing this. "SORRY BOYS! I'M SOOOOOO CHANGEABLE!"
- Tyres from Spaced does this frequently, with the camera angle often changing with his mood. Explained as a long-term side-effect of taking waaaaaaaaay too much ecstasy.
- The Caesars depicts Caligula as one of these; Caligula even says that he uses this to his advantage so that people do not know whether a given act of flattery will please him or anger him, thereby keeping them afraid of him.
- Cat in Victorious can go from happy to sad in under 4 sentences.
- London Tipton. One minute a crazy raging psycho, the next minute a sobbing heap of mush, the next minute icy calm, and finally party-girl cheerful.
- A pregnancy example from The Nanny. The combination of her pregnancy and her son moving away to college left Fran's emotions all over the place, pinballing around in seconds.
Niles: I thought tonight for a celebratory dinner, I would make salmon.Fran: [Morose] Oh, no, those poor little salmons. They spend their whole life swimming upstream just to be poached for dinner?Niles: I was going to barbecue.Fran: [Chipper] Ooh, mesquite? With a teriyaki glaze? That would be perfect for Brighton's celebratory dinner. [Crying] my baby's leaving. [Angry] Who put their finger in the cake!?Everyone else: [Slightly Confused] You did.
- Dickie Bennett of Justified is a villainous example, who can shift from sullen and sarcastic to faux cheer, to sadistic rage over the course of a scene. He's also possessed of a distinctly unreliable Hair-Trigger Temper—sometimes can keep his cool no matter how bad things are getting, while other times the slightest set back will set him off.
- Ross was like this between "The One With Ross's Sandwich" and "The One With The Girl Who Hits Joey", as a result of first getting depressed with all the bad things in his life, then snapping and developing his "rage", then being put on medication. This reaches its peak in the latter episode, where he goes from furious that Chandler is sleeping with Monica to delighted that Chandler is in love with Monica in about a second. He calms down a bit after that, but it still flares up sometimes, for instance in "The One Where Ross Is Fine".
- Pheobe was like this with her pregnancy hormones in "The One With The Worst Best Man Ever".
- Monty Python's Flying Circus has the man who's alternately rude and polite.
- Relient K: Whoever the song "Mood Rings" was about: "First she's Jekyll and then she's Hyde... at least she makes a lovely pair", indeed.
- Malfeas in Exalted is known to be bipolar on a huge scale, but the real Mood-Swinger among the Yozis is Kimbery, whose affections change like the tides - as soon as she's disappointed by you at all, she goes loveloveloveloveloveSOMUCHHATE. Being in the second category is a death sentence; the first, a death sentence suspended until you inevitably enter category two.
- One of possible monsters in Munchkin Card Game is a "bipolar bear" - he will attack you furiously or run away, depending on its current mood.
- Lucy from Thirteen has this dialogue with her boyfriend:
Lucy: ...And don't forget to change your facebook status to in a relationship. That way our profiles will be linked together like little love handcuffs.
Brett: (To Cassie, who is walking by) Oh hi Cassie.
Lucy: Are you flirting with her?!
Brett: No, I was just saying Hi.
Lucy: So you're saying I'm fat?
Lucy: Well, you never say anything about how amazing I look anymore.
Brett: Lucy, you are driving me crazy.
Lucy: See? Now that was sweet. And sweet makes me sweet. Got it?
- In Shrek The Musical, Fiona seems "a bit bi-polar" during "I Know It's Today".
- The Dance Dance Revolution announcer, or at least the one from DDR Hottest Party. He lavishes praise on you when you're doing well or even just okay, but the second your dance meter falls into the red he'll angrily demand that you stop sucking. Also, when you idle on the song menu he demonstrates all the patience of a spoiled six-year-old ("Bo-ring!").
- Anders of Dragon Age II is stated in the Codex to suffer from manic and depressive phases as of Act III, due to the Sanity Slippage caused by his Demonic Possession. His dialogue throughout the game tends to reflect this, ranging from calm and caring, to snarky, to obsessively focused on his goals, to self-righteously grandiose, to self-loathing and miserable, to downright psycho, with alarming speed.
- Due to programming, Cole Phelps from L.A. Noire. During interrogations, he'll typically ask a calm, polite question, and then if you select "Doubt" or "Lie", abruptly start screaming obscenities at the suspect, then return to normal for the next question.
- Persona 3: While not as extreme as some of the others on the list, Yukari Takeba frequently goes through random moodswings through the course of the game. Said mood swings get worse in The Answer thanks to her grieving over the main character's death.
- Perfectly understandable too, given the fact that, before the events of the game, she was (for the most part) a normal teenager.
- Silver from Sonic the Hedgehog. When the player sees him, he's usually either moping around or being in-your-face and energetic. Given the pervasiveness and length of time between some of these episodes, it's possible that he's actually bipolar.
- Naoto's Shadow is this in Persona 4, alternating between a Mad Scientist giving the real Naoto a "The Reason You Suck" Speech and a Fragile Flower bawling their eyes out.
- Cyrus of Pokémon Diamond and Pearl is revealed in Platinum to be suppressing his uncontrollable moods, which he believes to be caused by the inherently flawed nature of human spirit. It's suggested by his former neighbors that he snapped under pressure as a child and never quite got the help he needed.
- Wigglytuff in Pokemon Mystery Dungeon Explorers has this reputation (along with Hair-Trigger Temper), though at first it seems like its an Informed Attribute. After you fail to bring back a Perfect Apple however, he literally almost blows up the guild. Besides that, the aftermath of his Curb-Stomp Battle with Team Skull supports this.
- In Psychonauts, you delve into the brain of a former actress to control her mood swings. Her mind is represented by a stage where can change the atmosphere from cheery to depressing with a switch.
- Soul Series: Tira is either bloodthirsty-cheerful or bloodthirsty-angry. She can change semi-randomly during a fight.
- In her second appearance this escalated from Bipolar, to actual split personalities and her fighting style changes depending the current mood/personality.
- Arguably all characters in the Galactic Adventures expansion for SPORE, as players are only given 5 emotions to work with (happy, sad, angry, scared, and neutral which is just a different version of happy) when making dialogue portions for their user-created missions, and they're all expressed in the most exaggerated way possible without and transitions between them. This also makes certain character types such as the Deadpan Snarker and The Stoic very difficult to portray believably.
- This is the main gimmick of Super Princess Peach: the heroine has four different moods that must be used in various ways.
- The Happy Mask Salesman in The Legend of Zelda: Majora's Mask. There are literally no physical transitions between his extreme emotions.
- Troy Baker's Joker veers into this in Batman: Arkham Origins: he can go from cracking jokes to his underlings, to shoving a guy out of a window, to raving about how much he loves the fruitcake. Notably, this is before he's developed his obsession with Batman, which comes at the end of the game.
- Madison Li of Fallout 3 has a habit of changing her tone from hostile and antagonistic to calm within the same sentence.
- Aerie in Baldur's Gate II wavers more or less arbitrarily between "scarred but functional" and "if I can't fly I might as well just kill myself".
- Noire in Fire Emblem Awakening is notorious for switching between her timid and soft-spoken, and violent and loud personalities at random times.
- Arcueid from Tsukihime. Nothing too drastic though, unless you make her really angry.
- Zenith in Commander Kitty is prone to wild mood swings. Watch her go from indignant ranting to happily discussing where to hide her goons, or from total despair to omnicidal rage!
- In DMFA, for the 'cubi it's a racial trait linked to their emotion based powers. A 'cubi is both mercurial and feels emotions more strongly than any other creature or being.
- The fairy Red from Gunnerkrigg Court veers between smarmy affection, despondency, and rage. If anything, she gets worse after she becomes a human. (Maybe it's the hormones.)
- Zimmy is similar, though her personality is a bit more subdued. (Read: not psychotic.) Her mood swings revolve around her friend Gamma. An in-depth analysis of Zimmy's issues on the matter would make this page about twice as long, but the short version is this: Gamma acts as a grounding wire for the bulk of Zimmy's Reality Warper powers, which she can't control, and thus keeps Zimmy's mind mostly at peace. Zimmy is nonetheless aware that she's not a lot of fun to be around, and is terrified that if Gamma thought she had any other friends, she'd spend her time with them instead of Zimmy; between this fear, and the power Gamma can't drain away, her overall reaction to the world is erratic and designed to keep people at arms' length by whatever means necessary.
- Sollux of Homestuck has this problem, and tends to lapse in and out of Heroic Self-Deprecation repeatedly. It's part of his overall theme of duality and bifurcation, as Gemini in the Trolls' Western Zodiac motif.
- Sollux's ancestor-descendant Mituna also turns the intensity of Sollux's mood swings up a few notches, swinging erratically between being a raving, foulmouthed Jerk Ass and a cowed, apologetic Extreme Doormat. It may not have always been so bad, seeing as he suffered a Heroic RROD that severely crippled his mind before his introduction.
- Jean Poule in The Inexplicable Adventures of Bob!.
- Ménage ŕ 3 has Kiley Shefford, a trainee psychotherapist who sometimes seems like she could do with some therapy herself.note Her most dangerous flaw may be an excessive but fragile confidence in her own abilities. She jumps from cynical sarcasm to wild enthusiasm, from tearful panic to jumping someone, from "I'm such a good therapist" (strip #515, October 20th 2011, NSFW) to "I'm the worst therapist in the world", from ecstasy to tears, or from anger to sobbing, with minimal provocation.
- Without Garfield, Jon looks like he has inexplicable mood swings in Garfield Minus Garfield. Case in point.
- The 20 Questions-playing Akinator can switch between smug satisfaction and red-hot rage between one question and the next, if what he thought was a perfect guess is thrown off by an answer that doesn't fit the bill.
- The Nostalgia Critic. All it takes is one bad move from a film and he'll go apeshit. Case in point?
Critic: A BAT CREDIT CARD???????!!! I'LL KILL ALL OF YOU!*3 hours later*Critic: Sorry. I just get a little crazy when I see a BAT CREDIT CAR-!!!*12 hours later*Critic: ...RAPE MY CHILDHOOD YOU-
- Played for Drama in Demo Reel with Tom Collins. During a phone call message to Donnie, he goes from jovially commenting that SWAG is pretty awesome, to full-blown-stalker threats telling Donnie to not even think about ignoring him.
- Terry, the Bi Bi-polar Polar Bear.
Terry: I just want you all to know that I don't care if you're a boy penguin or a girl penguin, I just... Aw, heck, I'm just gonna come right out and say it: I love you all to pieces!
Penguin: Oh, thanks Terry. We all love yo—
Terry: GO TO HELL!! *Runs off crying*
- Aaahh!!! Real Monsters had Ickis, the Ugly Cute lead with serious issues. He could go from nervous stammering to bouncing off the walls to grossly inflated overconfidence and back in minutes. And that doesn't even get into his bouts of wide-eyed idealism and naivete...
- Avatar: The Last Airbender: Katara is pretty much this trope to a T. Justified given she's a teenage girl who's had a lot to deal with over the last few years.
- Also Prince Zuko. One minute, he's calm, focused, and disciplined. The next, exploding in a flurry of grunts, growls, and fireballs. Even as a good guy, his mood doesn't improve much until the end. This is why he cannot use Lightning Bending, which requires absolute control over one's emotions.
- Lunch Lady from Danny Phantom who switches from kind, grandmotherly figure to full-blown "I'll KEEL you" mode at the drop of a hat. Her alternate future daughter picked up the habit as well.
- The titular Invader Zim. One minute he'll spout about his next plan of attack, the next minute he'll calmly enjoy a plate of waffles.
- Heloise from Jimmy Two-Shoes tends to switch from Ax-Crazy Enfant Terrible mode, to sweet and innocent mode, to Deadpan Snarker mode, to flirtatiously lovable mode (around Jimmy), to pissed off mode and back again.
- Kim Possible:
- Doctor Drakken seems to go from mood to mood like an acrobat does on swings.
- In the episode "Emotion Sickness", Kim and Shego become Mood Swingers thanks to the Moodulators attached to them. Ron and Drakken end up being on the receiving end of all of their emotions.
- Hexadecimal in ReBoot has her mood swings lampshaded — her face consists entirely of a theater mask, and she has to manually wave her hand across it to change its exaggerated expression.
- Superjail - The Warden.
(sees dead bunny) "You... sick... bastard." (squishes dead bunny, merrily sends the bunny's kidnapper off in a rocket ship, and holds dead bunny up) "Heeey, little guy! Underneath all that precious fur..." (cuddles dead bunny mournfully) "All scared and all alone..." (pets dead bunny contentedly, starts singing) "If only~ they knew~ what it was like~ to be~ yyyyoooOOOOUUUU!" (rips dead bunny's skin off and gleefully wears it as a hat) "Jared, I want one of these for each and every inmate, not a moment to spare!"
- Lola Bunny from The Looney Tunes Show has a tendency to have little control over her emotions, one moments she can be crying her eyes out and the next she's laughing her ass off. Being a Cloud Cuckoolander, it could be attributed to her never being entirely sure what's going on around her.
- Ren from The Ren & Stimpy Show.
Ren: I'm gonna hit-cha! And you're gonna fall. And I'm gonna look down. And I'm gonna laugh. But first... first...! I gotta take a whiz! Don't you go anywhere.
- Made fun of in one episode of The Simpsons. Homer takes sleeping pills to sleep well through the night and Lisa reads off the side-effects, one which is Mood Swings. Cue Homer repeatedly saying "Mood Swings" in various moods.
- Blitzwing the Triple-Changer from Transformers Animated, who switches rapidly between three personalities/moods: Icy (stoick and calculating), Hothead (enraged and Hot-Blooded), and Random (who is... well, Random).
- Peg from Goof Troop can switch from being sweet and happy to terrifyingly angry in the same sentence, and effortlessly move back and forth between them. This usually occurs because she's addressing two parties at once, one she has a beef with and one she doesn't.
- Rapid cycling bipolar disorder (in which the characteristic mood swings take place in periods of days or even hours, rather than weeks as is more typical) somewhat resembles this trope, and as noted above most fictional characters with bipolar disorder are depicted this way despite it being comparatively rare.
- One of the key symptoms of Borderline Personality Disorder are rapid mood swings that can happen within hours. note This trope is so much a core indicator of that disorder, in fact, that some propose to change its name to "Emotional (dys)regulation disorder" because the term "Borderline" is outdated and carries too much social stigma.
- To be clear, the key difference between BPD and bipolar disorder is that mood swings in BPD are always a response to external stimuli (even if it is something as trivial as your pen being out of ink) while mood swings in bipolar disorder are spontaneous.
- Some people with PTSD have mood swings as part of the hyperarousal aspect of the disorder.
- Ivan the Terrible had mood swings as a side effect of the quicksilver he used to treat his pain. One bipolar episode had him beat his son to death in a fit of rage. He reacted with devastating sadness.