A character for whom every thing is funny, and everything is worth a laugh. They see the funny side of everything, and you can expect this character to laugh regardless of whether he just got hit with a pie or missiles are raining down from above. They'll laugh through sun, rain, sleet and snow, and they usually do it so much that it becomes a sort of Catch Phrase for them.
For villains, this often overlaps with an Evil Laugh, and, in fact, this trope is more common for villains rather than heroes or neutral characters, and this often crosses with Comedic Sociopathy. It's also common for crazy people.
Incidentally, the inspiration for this trope, spotted hyenas (Crocuta crocuta), aren't really laughing when they make their infamous vocalizations. It appears to be a form of communication used mostly when fighting for food or in social conflict.
Anime & Manga
- Hamburg, the Dumb Muscle of the Foxy Pirates in One Piece laughs at literally everything that happens around him. While, admittedly, some of these things are actually funny (like how a giant crewmate of his can never hear what anyone else says because he's so tall), he does it at every turn.
- One Piece also has Miss Valentine, who appears for a whole story arc as a main villain, but only has three or four lines that aren't laughter.
- While not prone to laughter as per the trope, Bellamy has "the Hyena" as his Badass Nickname.
- Not to mention Bellamy's boss, Donquixote Doflamingo. Dude never stops laughing smugly.
- Cyclonus from Transformers Armada.
- Kururu from Keroro Gunsou utters his famous 'ku ku ku' laugh, even when everything is going to hell around him. It seems like his standard reaction to everything.
- Haruhi Suzumiya: Tsuruya tends to burst into loud laughter at everything she finds even slightly humorous. Her first appearance in the show has her utterly fail to stay in character while making Haruhi's student film because she's laughing too hard. She spends the rest of the scene laughing hysterically while Kyon does snarky narration.
- Waji in Hare+Guu, has a rather creepy hyena like laugh. Apparently he believes laughing makes your worries go away. He was even compared to a hyena once.
- Interestingly there are a few hints he has a troubled home life, like being found in the middle of the night in the jungle,crying to himself.
- Elmer from Baccano! is always laughing or at least smiling, and spends his long life trying to make everyone else smile. He does this even when this would be completely inappropriate, such as just after the person has gone through a traumatic event, making it seem like there's something seriously wrong with him.
- Sakamoto from Gintama. He wasn't always like that though.
- Patti from Soul Eater.
- Margery Daw's Lord, Marchosias. Can overlap a lot with Evil Laugh as they are a pair of Blood Knights.
- Kid Buu very rarely says a word, and most of the sounds he utters are either insane screeches or maniacal laughter.
- Clair Leonelli from Heat Guy J, and his maniacal laughter...which even sounds like a hyena!
- Kusukusu from Shugo Chara. Her name even means "Tee-hee"
- The One-Scene Wonder that was Ash's (temporary) Haunter in Pokémon. It thinks everything is funny.
- Jan Valentine from Hellsing. Seriously, he sounds utterly deranged in the dub.
- The Joker, a quintessential Monster Clown, laughs at everything, especially death, destruction, and despair. Life is a joke to him, and all ironies are equally funny in his mind. He even known to laugh maniacally when he's the one on the receiving end. His mirth is so much that, when he stops laughing, it's a surefire sign that things are as bad as they can get.
- In The Dark Knight, Batman threw him off a building and he laughed hysterically on the way down.
- He also does this in the comics, in the arc "Lovers and Madmen", only rather than being thrown, he delibrately steps off, just to see if Batman will save him, despite having just gone on his very first rampage through Gotham City. This being, at the time, the official first encounter between the Joker and Batman, he survives, obviously. Not sure whether this example, or the Dark Knight, came first.
- One of the few things he doesn't find funny is someone explaining the joke, in fact this is one of his Berserk Buttons.
- In The Dark Knight, Batman threw him off a building and he laughed hysterically on the way down.
- During the Amalgam Comics crossover event for Marvel and DC, the Darkclaw, a hybrid of Batman and Wolverine, fought a cross between Sabretooh and the Joker—named the Hyena, of course. Basically, a shirtless Joker on 'roids and a healing factor, topped off by a mane of green hair.
- One story in an American-made comic set in feudal Japan featured a samurai, the principal courier for "the Great Lord", whose ability to see the humor in just about anything had caused him to be known as Harada the Jokester. Given a message to carry that would've forced the death of the two main characters, to whom he'd taken a liking, he picked a fight with a band of assassins, so they'd kill him before he could pass on the message. As the assassins closed in on him, he was laughing loudly.
- This was the trademark of "Laffy" Smith, one of the villains in the Dick Tracy strip.
Films -- Animation
- Ed from The Lion King, who is a literal Hyena, and whose entire dialogue consists of insane laughter, which only his partners are able to understand. The others laugh pretty often too.
- Goes straight into horror when the other hyenas ask him about his opinion of Scar calling them "friends" shortly after denouncing them to Simba, and his only reaction is to laugh and lick his lips just before they all maul and devour Scar; not the loud cackle, but a quieter snicker.
- The weasels in Who Framed Roger Rabbit?. Results in their demise.
- Judge Doom mentions that the weasels had some "idiot hyena cousins".
- The Ghost of Christmas Present in the 2009 version of A Christmas Carol. His constant laughter quickly moves from jolly to unsettling and becomes downright scary as he continues to guffaw as his body ages into a skeleton and then crumbles to dust.
- The crows in Dumbo.
Films -- Live Action
- In Freaked,, the Big Bads have a parody of Evil Laugh that made them examples of this; every line of dialogue they had was an evil laugh, which their henchmen could somehow understand.
- Uncle Albert in Disney's Mary Poppins.
- Star Wars' Salacious Crumb.
- The Detective from the Coen Brothers film Blood Simple.
- The Daffy gremlin from Gremlins2.
- Johnny laughs at all kinds of unfunny things in The Room. One particular example is a scene where Mark tells a story about a girl who ended up in hospital. It's fucking weird.
- What he says is "What a story", implying the story might sound far-fetched to him.
- Joe Cox the African gang member from RoboCop laughed at everything, especially when people got hurt.
- Fidget in Cecil B. Demented laughs(and fidgets) a lot, to the point of almost seeming like he's doing an impression of Dwight Frye.
- The Great Race - Prince Hoepnick (Jack Lemmon) is a cheerful fellow, loving the life he's living, constantly drunk, and punctuates nearly every sentence he says with a loud braying laugh. Ha HAAA Hhahaaa!
- Marco from Animorphs.
- Carcer from the Discworld novel Night Watch is the Psycho for Hire version of this.
- Also the kind of people who traditionally hired Igors.
In fact they would probably laugh at you if you said 'sausages'. They laugh at lots of things.
- Live and Let Die has Tee Hee Johnson, who is noted for his tendency to chuckle and giggle to himself for little or no good reason.
- The '90s The Untouchables series had some petty criminal who was laughing nervously, even as Capone's men beat him up. But that was more hysteria than humor.
- Star Trek: The Next Generation: Data remarks that the Holodeck audience for his comedy routine setting is literally programmed to laugh at anything.
- Warren Mears on Buffy the Vampire Slayer does this from time to time. He even laughs right before he shoots Buffy.
- Also, the kids possessed by the demon Hyenas in The Pack.
- There is a recurring Michael McDonald character from Mad TV who laughs at everything especially if he thinks he's going to die.
- The team of Anne-Marie and Tracy from The Amazing Race Australia are having such a good time on the race that they just do not stop laughing.
- Power Rangers: Rita Repulsa. She lets loose an Evil Laugh in almost all her lines.
- Harvey Kneeslapper from Sesame Street. The character was eventually dropped because the laugh was destroying Frank Oz's voice.
- Averted on at least one occasion, when one of his practical jokes backfired on him; his would-be victim ended up laughing at him, and he naturally failed to see the humor.
- Tim Curry's portrayal of Long John Silver in Muppet Treasure Island is a creepy hyena. At first, his laughs seem to just be the jovial nature of a simple ship's cook. As his true colors start to shine through, it starts to feel more and more menacing each time he starts.
- Marc-Olivier Fogiel in the French satirical show Les Guignols de l'info. Everything he says is pure jerkassery, and he frequently bursts on laughter after having humiliated someone. Bonus point for having an actual hyena as a pet.
- Bob and Ray had a recurring character known as "Charles the Poet", who would start out by reading a piece of awful poetry with dead seriousness, but within a few lines would completely lose his composure and break out into helpless laughter. This would get him yanked from the air well before he could get through to the end of the poem.
- Exalted gives us Adorjan, the Silent Wind, a Yozi who, when she speaks, only does so through laughter. This is partially because of a Charm she has (and her chosen can learn) which allows telepathic communication while forbidding the bearer from vocalizing anything other than laughter, and partially for other reasons.
- In Shakespeare's A Midsummer Night's Dream, some interpretations Puck can certainly be described as such.
- Particularly in the 1930 version, where he was portrayed by a teenage Mickey Rooney.
- Kefka from Final Fantasy VI is an evil example.
- Various characters in Higurashi no Naku Koro ni. This is seldom a good thing.
- Laurence "Moe" Curls in Phoenix Wright Ace Attorney: And Justice For All. Bad for his career, as he's a clown, and nobody else finds his jokes funny.
- Persona 4's Yukiko Amagi regularly has laughing fits that can last for several minutes.
- Laughing Octopus of Metal Gear Solid 4: Guns of the Patriots is an Axe Crazy example. Both of these traits are reactions to mind-raping trauma.
- Another Ax Crazy example is Aran Ryan from Punch-Out!! Wii, who laughs even as you beat the crap out of him. The only thing he won't laugh at is a Star Punch - those actually hurt him.
- The Jockey from Left 4 Dead 2 does literally nothing else. Out of all the Special Infected, the Jockey will probably become the one you want to kill the most, just to shut it the hell up.
- Ripper Roo, after being experimented on by Neo Cortex becomes literally Laughing Mad; all of his dialogue from that point on consists of insane laughter with subtitles.
- Iggy Koopa from Super Mario Bros..
- Father Grigori from Half-Life 2, who's on your side but nevertheless clearly has a screw loose. Escalated further in Concerned, where he laughs about once per speech bubble.
- In the town of Wimbich in Zelda's Adventure, there's a guy in a shop who seems to think that everything up to and including "lighting a shrine" is a laugh riot (6:15 through 7:30 of this Let's Play video).
- This is the reason one undead minion in Adventure Quest Worlds was given the name of Chuckles.
- Xan from Dragon Fable. Half his lines are manic laughs.
- Misha of Katawa Shoujo. Her signature "WAHAHA~!" is instantly recognizable by just about every player of the game.
- Coyote from Gunnerkrigg Court.
- Homestuck: Terezi Pyrope, befitting the only troll who's actually any good at trolling. She loves annoying everyone just a little too much. Her sprite is also always drawn with an open mouth, showing off the fact that trolls have many more teeth than humans. Similarly, her lusus proves to be a much more lighthearted one when it's reincarnated as the Dragonsprite.
- Cheese, of the Whateley Universe. What would you expect from the child of supervillains, who has decided that a really good codename is Cheese? In the story "Bad Seeds", he really lets loose.
- Dr. Hibbert from The Simpsons laughs at everything, and anything he doesn't find funny is usually the subject of a Take That.
- The sole purpose of Nelson is to laugh at others misfortunes.
- The Perils of Penelope Pitstop: Yak Yak, one of the Ant Hill Mob, always laughs at everything, even and especially when they're all doomed.
- Dan from Undergrads literally only ever laughs. That's all he ever does. To the point that other characters are beginning to wonder whether he's mentally deficient.
- Cosmo from The Fairly OddParents laughs at anything, including pudding!
- YOU SAID "PU", AND THEN "DING"!
- As mentioned above, the Joker, but special mention has to go to his protege in Batman Beyond, Little JJ a.k.a. Robin, who kills the Joker while laughing, only to break down into tears after he realizes what he's done.
Joker: That's not funny...that's not...
- Little Miss Giggles from The Mr. Men Show.
- Uhuhuhuhuhuhuhuh, Beavis and Butthead like, never stop laughing, ever, uhuhuhuhuhuhuh. It's, like, a Verbal Tic or something, uhuhuhuhuh.
- So much that on those rare occasions when they do stop laughing, it's either because something has just ticked them off or they're confused (I mean, more confused than they usually are).
- Taken Up to Eleven when Butt-Head is given laughing gas by the orthodontist because he won't stop squirming.
- Hyena from Gargoyles is this on occasion, possibly as a form of psychological warfare. Or she's just that mental.
- Jokey Smurf from The Smurfs generally finds everything funny.
- Flapjack takes this trope to ridiculous heights.
- Rufus from My Gym Partner's a Monkey, who is an actual hyena.
- Spongebob from the later seasons of SpongeBob SquarePants.
- The Teletubbies always laugh. They laugh because of their toys.
- Even the sun laughs.
- The Grapple family from Tale Spin.
- In the Swat Kats episode "Swat Kats Unplugged" we're introduced to Chopshop, a literal laughing hyena.
- Meadow from Lite Sprites constantly makes jokes, and fancies herself quite hilarious. Her friends, not so much:
Brooke: That's where Meadow's sense of humor finally made itself useful.
Meadow: What? Never!
- Baloney the Dinosaur, in his one-off appearance on Animaniacs, chortled at everything that happened, even the barrage of anvils he was treated to.
- In an episode of Rocko's Modern Life, a satellite crashes into the kitchen, a state-licensed contractor (an actual hyena) comes in to look at the damage. He immediately cracks up and proves to be of no help to Rocko.
- Tee Hee Hee from Toonimals
- Izzy from Total Drama Island is almost always seen laughing at someone or something, usually at her own crazy antics.