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[[quoteright:350:[[ComicBook/TheKillingJoke http://static.tvtropes.org/pmwiki/pub/images/zad_killing-joke-385_5251.jpg]]]]
[[caption-width-right:350: Some days are worse than others.]]

->''"Haven't you ever heard of the healing power of laughter?"''
-->-- '''ComicBook/TheJoker''', ''Film/{{Batman}}'' (1989 film)

Trauma and tragedy tend to follow characters like plagues, and they often break them down, turning them into insane, jaded shadows of their former selves. This can often happen in various ways, but the best way to tell if a character [[FreakOut just can't take it anymore]] is if they just break down and start laughing for no reason at all, or for all the wrong reasons. Usually, when this happens, they will continue to sit there, laughing uncontrollably, as if in a trance, until someone breaks them out of it, sometimes by a [[GetAHoldOfYourselfMan slap in the face]].

Expect the laughing character to either gain control of themselves and apologize for losing it (while still [[SanitySlippage emotionally fragile]], of course), or, alternatively, simply [[StrawNihilist stop caring about life]]. This may lead to them becoming [[TheStoic distant]], or become [[AntiHero more harsh than before]].

More often extreme cases occur, causing a character to turn to complete madness, going into an insane asylum.

On the flip side, villains are also prone to this. It is often shown as being fundamentally different from an EvilLaugh, usually as them either laughing a lot longer than normal, having the laugh sound more deranged than cold and boastful, or a combination of the two. This is normally used if the writer wants to characterize the villain in a much more psychotic light and have a more frightening nature than normal. Expect it to also be used for a VillainousBreakdown in some cases.

Like InsaneEqualsViolent, this phenomenon is rare in real-life instances of severe mental illness. In fact, a common characteristic of schizophrenia is the ''absence'' of laughter, or indeed of other indicators of emotion ("flatness of affect"). Of course, the TruthInTelevision here might come from Bipolar Disorder, where mania causes inappropriate laughter on a euphoric scale -- or Schizoaffective Disorder, which is the two in a blender. Then there's the simple fact that inappropriate laughter can accompany intense grief or anger, without actual mental illness needing to be involved - a related phenomenon is "hysterical laughter", where an intense bout of InelegantBlubbering starts to resemble a laughing fit.

Not necessarily related to EvilLaugh, but definitely a type of FreakOut. Is also a sure-fire sign of SanitySlippage. Also see PutTheLaughterInSlaughter for maniacs who engage in this regularly, and GigglingVillain for a constant if contained laugh. Sometimes overlaps into DieLaughing, especially if it is the result of a VillainousBreakdown. May be the cause of OminousAdversarialAmusement. Compare {{Corpsing}}, involving laughter at inappropriate times ([[TensionCuttingLaughter probably because repressing is maddening]]).

Not to be confused with ''VideoGame/FinalFantasyVI'''s [[AwesomeMusic/FinalFantasy Dancing Mad]], although that game did act as the TropeNamer in regards to its main villain.



[[folder:Anime & Manga]]
* In ''VisualNovel/SteinsGate'' basically every time Hououin Kyoma enters the scene, though [[spoiler:it's actually just an act]].
* Suzaku Kururugi [[https://www.youtube.com/watch?v=vCQeGr24XUA does this]] in episode 19 of season 2 of ''Anime/CodeGeass'' after [[spoiler:accidentally [[NukeEm killing several million people with the FLEIJA bomb]]]]. This led to the creation of several {{Fan Nickname}}s, namely Laughzaku and [=LOLzaku=]. Sometimes [[ForTheEvulz Lulzaku]] is used.
** Lelouch does this as well at the end of episode 17 in the first season. He has other [[EvilLaugh laughs]] too, but that's the only one that actually sounds legitimately crazy.
*** [[https://www.youtube.com/watch?v=00EjISW5vsU The English dub of Episode 23 also manages this perfectly.]]
* In ''Manga/YuYuHakusho'', after being defeated and losing his entire fortune, Tarukane goes into convulsions of insane laughter, which only end after Toguro kills him.
* ''Manga/JoJosBizarreAdventureStardustCrusaders'': In the midst of a seemingly hopeless battle against the Sun Stand, Kakyoin, Jotaro and Polnareff all finally burst out in creepy hysterics while taking desperate shelter from the heat and laser rays. Joseph assumes that they all lost it. However, it's a subversion: They're all laughing because they figured out that the nearly unstoppable Stand actually has a glaring weakness.
* ''Manga/ShamanKing'''s BigBad, [[FauxAffablyEvil Hao Asakura]] does this near the end of the anime.
* In ''Manga/AzumangaDaioh'', after a BeachEpisode and everyone's back to school, quote Tomo: "this is the first day of vacation" repeating it like a mantra, following a Butthead-like laughter.
* Appears in the series and film ''Anime/TheVisionOfEscaflowne'', especially with AxCrazy Dilandau.
* ''Manga/FrankenFran'': Mr. Umimiya appears on the verge of a laughing nervous breakdown upon discovering his long lost daughter Ruri's (whom a maniacal cult worshipped as their prophet) body had become a part of the facility they're standing in due to the cult requesting Fran that she create an enormous artificial body when she fell ill.
* ''VisualNovel/HigurashiWhenTheyCry''. All over the freaking place.
** In fact, the first thing you see in the second arc, even before the opening, is a scene of [[spoiler:Rika stabbing herself in the neck while Shion laughs maniacally]]. It then takes about 10 episodes before you're finally told the context, and that makes it even creepier.
** For your viewing pleasure, [[http://youtu.be/-OJek7d6ars some]] WebAnimation/YouTubePoop of Shion laughing...for ten minutes.
* In the intro of ''Anime/ParanoiaAgent'', everyone is laughing. In the most unlikely situations, such as a guy in freefall, a drowning woman... what better way to tell you're about to get [[MindScrew mindscrewed]]?
* Kotonoha from ''VisualNovel/SchoolDays'' does this frequently after her descent into [[{{Yandere}} crazyville]].
* Precia Testarossa in ''Anime/MagicalGirlLyricalNanoha'', although she was fairly mad to begin with.
** Jail Scaglietti does it frequently.
* ''Anime/PuellaMagiMadokaMagica'': Sayaka goes a bit nuts on [[MonsterOfTheWeek Elsa Maria]] in a nightmarish scene that shows just how close the poor girl is to the DespairEventHorizon. [[spoiler:It helps the creepiness that the witch superficially looks like her love rival, Hitomi]].
** Also, the monstrous witch Walpurgisnacht, who won't stop letting out peals of echoing laughter while taking a humongous beating. In this case, it underscores both her inherent madness, and the [[HopelessBossFight utter futility of fighting her]].
* Quatre from ''Anime/MobileSuitGundamWing'' after witnessing [[spoiler:the deaths of his father and most likely his sister Iria (it's only confirmed in the manga version of the scene)]].
* ''Manga/DeathNote'': the deleted scene where [[spoiler:Light stays in the graveyard after L's funeral]], starts laughing madly, proceeds to crawl on top of [[spoiler:L's grave]] and shouts [[spoiler:"What do you think of that, L? This is my perfect victory! That's right—'''''I win!'''''"]] with a crazed look on his face... and looks suspiciously like he's humping [[spoiler:L's grave]].
* While he's sane afterward, the new Greed of ''Manga/FullmetalAlchemist'' [[spoiler:Ling]] is shown ending his PainfulTransformation with a frightening SlasherSmile and some truly [[EvilLaugh maniacal laughter]].
** Edward has one after he realizes that [[spoiler:trying to resurrect Trisha was a SenselessSacrifice.]]
* Alucard of ''Manga/{{Hellsing}}'' certainly enjoys [[http://www.youtube.com/watch?v=mY79nBC-u1A many]] inappropriate moments of insane laughter...but as he was crazy before, and is crazy after, the incidents don't represent any character development for him.
* Hikari of ''Anime/SpacePirateMito: A Pair of Queens''.
* ''Lightnovel/FullMetalPanic''. Kaname has a crazy laugh that she gives whenever she's lying about something -- such as the possibility of being attracted to that nutcase Sōsuke. Or denying that his latest bone-headed antic bothers her in the least. [[{{Tsundere}} Be afraid. Be very afraid.]]
* Yoko Wakana, the mad policewoman from ''Anime/FullMetalPanicFumoffu'', plays the trope straight.
* In ''Manga/BarefootGen'', Gen's mother Kimie falls into this. It's quite appropriate after watching her entire family burn to death amongst their pleas for help.
* [[MadScientist Doctor Franken Stein]] of ''Manga/SoulEater'' does this on several occasions. ''Definitely'' the SanitySlippage variety.
** The most striking would have to be after his fight with Medusa, with Stein breaking into a ''lovely'' example as stands with his scythe as the witch's blood rains down on him. Madness, apparently, feels good.
** Anyone under the influence of the Black Blood would do this. Crona and [[spoiler:Maka]] are examples.
** Giriko does one in chapter 75.
* Uchiha Sasuke from ''Manga/{{Naruto}}'' has an epic one in chapter 483, coupled with SanitySlippage and VillainousBreakdown in a fashion very similar to his brother.
** Not to mention [[AxCrazy Hidan]] of the Akatsuki. This guy wasn't sane to begin with, but once he gets into his rituals...
** Gaara has a great one during his fight with Naruto.
** In chapter 356, Kabuto has lost quite a bit of sanity following [[spoiler:Orochimaru's death]] and reveals he has absorbed Orochimaru's remains. At one point he bursts into hysterical laughter.
** In chapter 577 Kabuto does this after talking with [[spoiler:the resurrected Itachi]].
* Andrea of ''Anime/{{Gankutsuou}}'' is not exactly sane. One of the ways he shows this is by giggling/laughing creepily at random times.
** In one scene, the Count watches Albert leave his ship, quite peeved with him. Although we're led to presume that the guy is deep in grief over the event, we quickly see him break out into hysterical laughter. And from then on, he's out there, madly pursuing his revenge.
* AxCrazy CreepyChild Gretel of ''Manga/BlackLagoon'' laughs once when Eda asks her why they're still after Balalaika even though they killed the guy who hired them.
* ''Anime/GunXSword'': Van gets this for a moment when he sees the Claw pass.
* Mukuro of ''Manga/KatekyoHitmanReborn'' was never entirely sane to begin with so he does this a few times, most notably during his fight with Tsuna.
** And Daemon Spade. In chapter 329 he orders Enma to "take Sawada's skull and crush it like glass", and then he laughs maniacally...
* [[AxCrazy Grimmjow]] of ''Manga/{{Bleach}}'' laughs madly as he's beating the crap out of Ichigo during one of their fights and right after he kills Luppi.
** MadScientist Szayel does so at times.
** The Inner Hollow[[spoiler:/'''Zangetsu''']] also does this often.
* ''Manga/FutureDiary'': [[{{Yandere}} Yuno]] does this quite a few times.
* [[AxCrazy Alois]] [[CreepyChild Trancy]] of ''[[Manga/BlackButler Black Butler II]]'' out of nowhere breaks into hysterical laughter when he's alone in his room in episode 1 to help show how insane he is.
** On the other side of the spectrum, [[spoiler:Ciel]] gives us an absolutely geelful one after the circus arc, when he travels to the workhouse only to find out that it's in ruins. It's frightening [[ItMakesSenseInContext in context]], considering that the revelation would mean that the circus children all died trying to protect ''nothing''.
* ''Anime/DragonBallZ'':
** Broly definitely applies, especially in the flashbacks where it is clear that his laughter was uncontrollable after destroying at least one planet as a child.
** Frieza also gives one off while destroying Planet Vegeta. Well, he did seem a bit too exhilerated at blocking Bardock's attack as well as destroying Planet Vegeta.
** Majin Buu in his true, Kid Buu form. Kid Buu is, by a significant margin, the [[AxeCrazy batshit-craziest]] of the Buus, and pretty much 95% of his dialogue is either grunts/screams or deranged laughter to show just how far off his rocker he is.
* ''Anime/YuGiOh'' has its fair share, most notably with [[SuperpoweredEvilSide Yami Marik and Bakura]], although Kiryu of ''[[Anime/YuGiOh5Ds 5Ds]]'' outdoes them all.
** And then Vector of ''[[Anime/YuGiOhZEXAL ZEXAL]]'' proceeds to outdo him.
** It's not just with those guys, either--Noah had an insane bit of laughter like this in his arc, after which he temporarily believed himself to be Seto. He snapped out of it pretty quickly, though.
** Jonouchi laughs hysterically (After being Brainwashed by Marik) at an injured Yugi during their Death-Duel. however this is cut from the 4kids version...For some unknown reason.
** Pandora (Arkana in the dub), and how!
* [[spoiler:Nanamine]] in Manga/{{Bakuman}} after [[spoiler:his manga drops to 19th and the rest of his online contributors desert him for lying about his rankings]].
* ''Manga/OnePiece'':
** [[spoiler:[[TheHero Monkey D. Luffy]] [[HeroicBSOD does]] [[TearJerker this]] [[MyGreatestFailure the moment]] [[DespairEventHorizon after]] [[WhamEpisode Portgas D. Ace dies]].]]
** Donquixote Doflamingo is pretty much this series' version of ComicBook/TheJoker, so he's usually this. But it's most obvious in the Dressrosa arc, when he turns from recurring sideline psycho to the main antagonist, after finding out just how severely he underestimated the Straw Hat Pirates.
* Occurs occasionally in ''Manga/PandoraHearts'' such as in chapter 67 by Miranda. And in episode 15 by Oz when he's in LoveMakesYouCrazy mode for Alice.
* In ''Manga/WolfGuyWolfenCrest'' Inugami shows Haguro his werewolf form causing him to go crazy from it and laugh insanely.
** Ryuuko does this in chapter 65.
* Akito does this in episode 25 of ''Manga/FruitsBasket'' while tormenting Tohru.
** Akito also has a tendency to do this in the manga.
* ''Manga/RosarioPlusVampire'': Tsukune's Ghoul form definitely counts.
** Akuha does so at the end of chapter 53 after breaking down and seeing Moka with Tsukune.
* ''Manga/{{Berserk}}'', with all of the madness that happens in this universe, expect it to happen a lot.
** Jill laughs during the climax of the fight between Guts and Rosine, when the slimy, deformed corpse of a child that was undergoing Rosine's apostle spawn transform spilled from its cocoon. Jill remarked that the experience pretty much [[BreakTheCutie ruined her childhood.]]
** Griffith, upon his DespairEventHorizon and his [[BungledSuicide failed attempted at suicide.]]
** And then there's Guts, who is the most disturbing case. He did this ''a lot'' during his Black Swordsman days, caving in [[HeWhoFightsMonsters deeper and deeper into insanity with each apostle kill.]] His laugh sends extra chills down the spine when he flashes his SlasherSmile afterward.
* ''Manga/PeacemakerKurogane'': Suzu gets one of these in the sequel manga, after he goes AxCrazy.
* In ''Manga/PrincessKnight'', when Friebe finds out that the brave knight she planned on marrying was really a princess in disguise, she bursts out laughing and shouts "That's too perfect!" She pulls herself together and agrees to help the princess escape her pursuers.
* [[Manga/RurouniKenshin Shishio Makoto]] does this [[spoiler:[[ManOnFire as he burns to ashes after overdoing in his final battle against Kenshin.]]]]
* Jeremy when he finds out that [[spoiler:Greg's car crashed thanks to VehicularSabotage]] and when he is moved dorms because he [[spoiler:kissed his roommate William. He laughs because he finds it ironic that he gets in trouble for kissing his roommate, yet he is sexually abused every weekend which leads William to GetAHoldOfYourselfMan]] in ''Manga/ACruelGodReigns''.
* [[Anime/CowboyBebop Mad Pierrot Tongpu]], full stop. A [[NighInvulnerable seemingly indestructible]] [[AxCrazy psychopathic]] assassin. The audio for the preview for [[VillainOfTheWeek his episode]] is just his [[EvilLaugh maniacal laughter]] for 30 seconds.
* In a very jarring scene, [[spoiler:[[TheStoic Annie]] [[TheMole Leonhart]] ]] in ''Manga/AttackOnTitan'' after TheReveal. The SlasherSmile included along with it only signals that things are about to get ''very'' bad for everyone.
* In the penultimate issue of the ''Manga/{{Area 88}}'' manga, Shin emotionally overwhelmed by [[spoiler: the deaths of Saki, Mickey, and Sela that he starts laughing uncontrollably. He returns to his senses when Kanzaki contacts him.]]
* Kurumi Tokisaki from ''LightNovel/DateALive'' does this several times, such as summoning a second spacequake before [[spoiler: Kotori in her Spirit form]] stops it.
* ''Manga/TokyoGhoul'' includes a particularly disturbing scene, during Kaneki's 10-day long marathon torture. When [[TortureTechnician Yamori]] sticks a centipede in his ear and wraps duct tape around his head, Kaneki begins laughing hysterically while the agitated insect begins crawling around and stinging him. Seeing his victim laughing instead of screaming, Yamori joins him into the crazed laughter.
** Eto does this as she's declaring her love for Kaneki as he throws her mutilated body off of a building.
** [[spoiler: Mutsuki breaks down into hysterical laughter, after seeing Torso's mutilated body done at his hands and realizing the full scale of his past crimes.]]
** Kaneki does this again in season 2 of the anime when fighting Shinohara in his kakuja form.
* Both Mashiro and Kuroi from ''Manga/ThouShaltNotDie'' end up doing this but for different reasons. Mashiro ends up doing it when her day ends up a bit to rotten and she ends up [[BewareOfTheNiceOnes snapping]] [[TheBerserker after]] being shot. [[SociopathicHero Kuroi]] ends up doing it since he delights in the carnage Mashiro is causing leading him call out that he was right in believing in her and [[InLoveWithYourCarnage ends up declaring his love to her]].
* [[HijackedByGanon Akira Takaoka]] from ''Manga/AssassinationClassroom'' breaks into a fit of hysterical laughter [[spoiler: when he blows up the remedy to cure the students who were poisoned by him during the Assassination Island arc, [[BerserkButton further pissing off Nagisa.]]]]
* ''Manga/ZatchBell'': Dalia Anjé, a somewhat notable antagonist from the Ancient Mamodo arc. The spells are her only dialog; beyond that, it's just mad laughter.

[[folder:Comic Books]]
* This is generally how Franchise/{{Batman}}'s ArchEnemy ComicBook/TheJoker is portrayed as going insane. [[GoMadFromTheRevelation Upon seeing his new, ghastly appearance]], he laughs uncontrollably while clutching his hair in anguish. The Joker is also frequently shown laughing excessively long after he's gone mad.
* A flashback in ''ComicBook/TheSandman'' shows this happening to Delight during her transformation into Delirium.
* In a flashback to the future, [[Comicbook/SpiderMan Hobgoblin 2211]], after having her brain warped by a computer virus, cackles psychotically and goes on a rampage.
* The ComicBook/GreenGoblin has shades of this, and the current Hobgoblin has a weaponized laugh [[spoiler:seeing as he's Phil Urich.]]

[[folder:Comic Strips]]
* In an early ''ComicStrip/{{Garfield}}'' arc when both Garfield and Odie run away, Jon calls out for them, thinking they're playing a joke. Then, he starts laughing. [[http://images.ucomics.com/comics/ga/1986/ga860828.gif Cue his neighbor's reaction]]:
-->'''Hubert''': Call the wagon, Reba! That's not a natural laugh!

[[folder:Fan Works]]
* In the ''WesternAmination/JackieChanAdventures'' and ''WesternAnimation/{{WITCH}}'' crossover fanfic ''Fanfic/{{Kage}}'' (part of ''FanFic/ProjectDarkJade''), Drago does this during his VillainousBreakdown, starting when he casts the spell to cast Jade from her reality (as part of his being a SoreLoser, he wanted to taint her victory, as he considered her his ArchEnemy), and continuing even as he and and his father are dragged into their prison.
* Hago from ''Fanfic/TheLionKingAdventures'' is in love with this trope.
* In the ''Franchise/HarryPotter'' DarkFic ''FanFic/TheJadedEyesSeries'' Harry does this on a couple of occasions. The most notable one is his VillainousBreakdown when he ''snaps'' during the Yule ball:
-->''He stood in the middle of it all in a puddle of blood as more poured down his front and it was almost ironic that a few heartbeats later Harry was hit by another stray curse. Clark had joined the fray with his mother and luckily his jinx was almost harmless. It only banished the top part of his clothes away and that was when Harry started shaking. In the end it wasn't the teachers that stopped the chaos building inside the ballroom... it was the sound of sharp cold laughter.\\
It pulled everyone's attention as they turned their eyes to Harry who stood bleeding with a star burst wound on his chest blood flowing from him steadily as he laughed. Harry laughed harshly with no humor as he raised a shaking hand to his face inspecting the blood painted on it before he fisted his hair with both hands and cackled brokenly. Blood was smeared across his face; he was covered in spatters of blood giving him a ghastly image. The cool rush of the air reminded him that now most of his worst scars were on display and made him cackle harder.''
* In ''[[Fanfic/NewGamePlusOnePiece New Game Plus]]'', when Dadan sees Luffy’s record-breaking bounty poster, she falls into a laughing fit that lasts at least 10 minutes.
* Twilight Sparkle in ''Fanfic/PagesOfHarmony'' does this several times, one of the more notable ones from Chapter 11 when she's [[spoiler:bleeding from wounds caused by an AxCrazy Fluttershy]] after [[spoiler:Kindness has been taken]].
--> ''"Ha, I'm no masochist, my friend!" Twilight was shaking her head in response to the other pony's inquiry, gasping for breath from her half-shrieks. "Heheh, haven't you heard that, hahaha, laughter a way to trick your body into, haha, not feeling pain?!" Her smile widened as she managed to dodge [[spoiler:Fluttershy]]'s frenzied attacks, angling herself to more easily control the blood flow from her wound. "Heheheh, that's why I laugh, [[spoiler:Fluttershy]]! It enhances me! I sill feel pain, but, heheheh, it's not enough to kill me!" Her eyes were bright despite the obvious pain in her body, practically drunk with the imagined extent of her plan and the laughter which accompanied it. "Imagining helps too, just as I'm doing now, ha, thinking of just how existence will be when I've helped purify it under my guidance as a good friend and teacher! [=HahahahaHA!=]"''
* ''Fanfic/SunsetOfTime'', in a flashback we see the StartOfDarkness of the BigBad, Vesper Radiance. At the sight of [[spoiler:Twilight's coronation]], she breaks down first into giggles, then into hysterical laughter, declaring her intent to KillEmAll all the while.
* ''Fanfic/ThisBites'': [[SelfInsertFic Self-Inserted]] character Jeremiah Cross becomes this whenever things get dangerous; that is, when his adrenaline junkie tendencies kick in.
* In the ''WesternAnimation/MiraculousLadybug'' fic ''[[http://archiveofourown.org/works/6248479/chapters/14316103 I Do?]],'' this is one of several reactions from Adrien/Chat Noir after he ''finally'' realises that [[spoiler:his ([[RunawayBride until recently]]) fiance Marinette and his crime-fighting partner Ladybug who he once had an unrequited crush on are the same person]].
-->He didn't even know he was laughing until he was doubled over and falling to his knees. The crack that was sent through his body as he collided with the roof hardly registered, his stomach still wanting to throw itself up as his laughter grew manic.
-->But perhaps laughter wasn't the right word to use. He wasn't sure there was a word for it. Insane cackling, maybe, accented by sobs and tears that tore him in the same moments. Two conflicting actions that felt as though they were ripping his body apart.
-->A mental breakdown. That was what it was. He was having a mental breakdown.
-->Because the two women he'd loved were the same person, and she'd rejected him twice for himself and he'd fallen in love with her twice and now they were standing on a rooftop after she'd abandoned him at the altar for himself!
* ''Fanfic/DoingItRightThisTime'': Shinji has this reaction when he finds out what Rei said to his father, and again when she snarks (accurately) about how them being [[PeggySue time travellers]] and being completely mad [[BadFuture is not at all mutually exclusive.]] Asuka is more than a little creeped out.
* ''Fanfic/MrAndMrsGold'': Unicorns have a hallucinative bite. When one manages to bite Belle, she devolves into a giggling mess.

[[folder:Films -- Animation]]
* Franchise/DisneyAnimatedCanon:
** ''Disney/TheLionKing'' has TheHyena, Ed, who communicates entirely with obnoxious laughter. Banzai and Shenzi also qualify, but to a lot lesser extent. Cancelled storyboards indicated that [[spoiler:Scar]] would have undergone a heavy dose of Laughing Mad shortly after throwing Simba off Pride Rock before being consumed in the flames that destroy Pride Rock.
** It was also originally intended that Gaston from ''Disney/BeautyAndTheBeast'' would have undergone similar reactions to ComicBook/TheJoker from ''Film/TheDarkKnight'' when [[spoiler:falling to his doom upon stabbing the Beast (ie, proceed to laugh maniacally while falling)]].
** In ''Disney/TheHunchbackOfNotreDame'', Frollo laughs evilly as he goes to stab Esmeralda with his sword. Given that his next line suggests he thinks he's doing God's will ("And he will strike down the wicked, and cast them into a fiery pit!"), it's pretty likely he'd also gone mad with power.
** ''Disney/{{Aladdin}}'':
*** Subverted when Jafar starts laughing for seemingly no reason while he's being searched for by the guards, causing Iago to think he's gone insane, but then he stops and explains that the genie lamp he thought was lost forever was in the hands of "Prince Ali".
* Buzz Lightyear in ''WesternAnimation/ToyStory'' does this after realizing he's just a toy. ("You see this hat? I am Mrs. Nesbitt!") He stops after [[GetAHoldOfYourselfMan Woody slaps him]] with his own detached arm.
* In ''Animation/FiringRange'', a general start laughing madly after [[spoiler:realizing he can't stop the tank from killing him.]]

[[folder:Films -- Live-Action]]
* Richard Attenborough's character in ''Film/TheFlightOfThePhoenix1965'' when he discovers that [[spoiler:the man building the plane to take them out of the desert, and save them from slow and painful death, only has experience designing model airplanes.]]
* Norman Bates occasionally laughs at inappropriate points during his dinner with Marion in ''Film/{{Psycho}}''. He also lurches from laughter to complete seriousness a couple of times, which is equally scary. {{Downplayed|trope}} in that it's a nervous chuckle rather than a full-lunged hysterical laugh.
* Sirius Black, when convicted of killing Pettigrew in the movie of ''Film/HarryPotterAndThePrisonerOfAzkaban''.
** And then once again in the film version when Harry is set on killing him. This is a strong contrast to the book's character: [[DullSurprise "You're going to kill me, Harry?"]]
* ''Film/BeyondReAnimator'': After Philip's girlfriend is murdered, Dr. Herbert West brings her back to life by infusing her with the lifeforce of the corrupt warden who killed her along with his previously developed reagent so she can retain her memories, skills, and motor functions as a zombie. Unfortunately she comes back as a kinky crazed and dangerous zombie and Philip is forced to incapacitate by cutting off her head. When the guards find Philip weeping over her headless corpse, they drag him away as he tries to convince them that she is still alive by urging her and her headless body to speak to them. When she doesn't respond, he goes into a fit of insane laughter and then when he and the guards are out of sight, her head starts laughing and thus the movie ends.
* In many ''Theatre/{{Hamlet}}'' adaptations Ophelia's madness is like that: she switches between sadness (tears) and moments of happiness (insane laughter).
* Happens to Dr. Leo Marvin in ''Film/WhatAboutBob?''
* In the 1932 film ''Film/TheMummy1932'', after Ralph Norton sees the eponymous creature rise from its tomb and walk off, he is found giggling insanely and gibbering "he went for a little walk!"
* Creator/DwightFrye's Renfield in the 1931 ''Film/{{Dracula|1931}}''.
* The ''Franchise/EvilDead'' series is quite fond of this trope.
* Cody Jarrett winds up this way in ''Film/WhiteHeat''.
* Chief Inspector Dreyfus in ''The Pink Panther Strikes Again'' has a small bit of this after being "saved" by Clouseau on the day of his sanity hearing, triggering his escape from the asylum and sending him on a course to try to TakeOverTheWorld.
* Insurance fraud investigator John Trent punctuates his [[GoMadFromTheRevelation snapping mind]] with laughter at the end of ''Film/InTheMouthOfMadness'', due to [[spoiler:surviving a [[CosmicHorrorStory Lovecraftian]] [[TheEndOfTheWorldAsWeKnowIt apocalypse]], only to witness the entirety of his ordeal play out as a movie adaptation of an [[TomeofEldritchLore evil novel]].]]
* The "Daffy" gremlin in ''Film/Gremlins2TheNewBatch''.
* Baron Vladimir Harkonnen in the 1984 film adaptation of ''Film/{{Dune}}'' definitely qualifies, given how the film basically made him even more deranged in it than in the book or the TV miniseries.
* The Joker from ''Film/TheDarkKnight'' embodies this trope. Heck, he was even laughing when about to face certain doom before Batman saved him from hitting the ground.
* In the 1989 ''Film/{{Batman}}'' film, the Joker laughs a ''lot'' during the film, with him going way off the deep end near the climax when he is taunting Batman and Vicki while they are hanging for dear life. Joker even lampshades it in the same climax, where he goes into a fit of laughter, turns to a gargoyle behind him and yells "What're you laughing at?!" and then resumes laughing.
* ''Film/AustinPowers in Goldmember'' had Dr. Evil dunking the Japanese CorruptCorporateExecutive Mr. Roboto into his "sharks with lasers on their head", which were gifts from his son Scott Evil. Although Dr. Evil and his followers did a simple EvilLaugh, Scott Evil's laughter, as well as Dr. Evil's horrified reaction to Scott Evil's amount of laughter, was more similar to Laughing Mad.
* After a long and miserable afternoon watching his dream home literally go to pieces on him, Walter and his fiancée Anna in ''Film/TheMoneyPit'' try to prepare a relaxing bath, only to have the tub sink through the floor and shatter into smithereens in the foyer below. [[http://www.youtube.com/watch?v=9CJ9EDtZ2p8 Walter's reaction]] is both a sterling example of this trope, and one of the funniest parts in the movie.
* Data in ''Film/StarTrekGenerations'' briefly goes laughing mad while attempting to investigate with Geordi the space station that Dr. Soren was working on, due to a combination of both the dampening field in place as well as Data's emotion chip going beyond his control.
* ''Film/WhoFramedRogerRabbit'' has the weasel Psycho, who giggles and laughs a lot.
* In ''Film/EightHeadsInADuffelBag'', one of the main character's best friends goes exactly this kind of crazy after having been tortured by a Mafia hitman, repeatedly told he's going to be killed, and forced to cut off the heads of cryogenically frozen people as replacements for the missing ones, among various other extremely stressful events. The final straw was when the aforementioned hit man started talking about using his head as one of the replacements. [[FromBadToWorse He spends the rest of the movie getting worse]]
* In ''Film/DonnieDarko'', Donnie laughs hysterically when he finally [[spoiler:comes to terms with the fact that he's going to die and is waiting to be crushed by the airplane turbine]].
* In the film adaptation of ''Film/TheWizardOfOz'', the Wicked Witch of the West frequently bursts into hysterical, exhilarated laughter whenever pain and suffering caused by her is happening.
* In ''Eye for an Eye'', Karen [=McCann=] starts laughing hysterically during her daughter Julie's funeral.
* In the 1951 ''Film/{{Scrooge 1951}}'', when Scrooge wakes up on Christmas morning and can't stop laughing out of joy, his housekeeper thinks, justifiably, that he's gone quite mad.
* ''Film/TheAdventuresOfPriscillaQueenOfTheDesert'': Adam/Felicia is running for his life, in heels and a dress, from a pack of enraged Australian rednecks... and he's ''laughing his ass off'' until they catch him.
* In ''Film/TheTrumanShow'', Truman bursts into laughter several times [[spoiler:when he tries to call out his "wife" on the fact that the world he's in is fake.]]
* The bad guy in the third ''Film/{{Flodder}}'' movie completely loses it when an attempt to destroy the Flodders and their party by crashing a tanker truck into their house instead causes the entire rest of the neighbourhood to burn down, including his own home. He bursts into manic laughter as he's watching his own fireworks go off.
* Film/JamesBond in ''Film/CasinoRoyale2006'', while he is being [[ColdBloodedTorture tortured]] by [[BigBad Le Chiffre]].
--> "Now the whole world's gonna know that you died scratching my balls!"
* In the movie adaption of ''Literature/IMissYouIMissYou'', Tina goes for a short walk with her friend Frida to calm herself down shortly after her twin sister Cilla died in an accident. They pass the school's theater and Tina remembers how Cilla, who was director of the school's theater group, predicted that everyone will cry at her theater performance. Tina begins to laugh hysterically at this memory until Frida [[GetAHoldOfYourselfMan slaps her several times]].
%%* ''Film/{{Reality}}'' ends with one of these, courtesy of [[spoiler: Luciano]].
* ''Film/AssassinsCreed2016'': Callum giggles deliriously as he's dragged to his second trip in the Animus while also singing Patsy Cline's "Crazy", because he's going through SanitySlippage thanks to the Bleeding Effect.

* Creator/WilliamFaulkner's Darl from ''Literature/AsILayDying''. Near the end, he goes insane and when he's not reciting a MadnessMantra of "yes, yes, yes, yes...", he's laughing his head off.
* [[HunterOfHisOwnKind The Thorn of Istra]] from Creator/HollyBlack's ''Literature/TheColdestGirlInColdtown''.
-->"The Thorn of Istra, the mad vampire. [[[TheHero Tana]]] thought of the grainy video of him she had seen, head tipped back, [[AxCrazy so covered in blood]] that she hadn't remembered his features, hadn't remembered him as looking like anything but a monster, laughing, [[LaughingMad endlessly laughing.]] Mad as a dog. Mad as a god. [[spoiler: [[LoveInterest Gavriel.]]]]"
* Bellatrix Lestrange from ''Literature/HarryPotter''. All the freaking time.
** Sirius Black - after his best friend James Potter and his wife Lily Potter died, started laughing as he was arrested [[spoiler:although he was in fact innocent]]. The laughter was probably a combination of all the emotions piled up on him, like [[spoiler:betrayal]], grief, and hatred.
** During the big fight at the end of ''Literature/HarryPotterAndTheOrderOfThePhoenix'', Ron gets hit by an "IntoxicationEnsues" spell and becomes uncontrollably giggly despite still being in mortal danger.
** In the same book Harry starts laughing at ''Bellatrix'' [[spoiler: after she kills Sirius]] and realizes he sounds like her when she frantically [[spoiler: tries to get him to give her the prophecy, which has been destroyed]].
* Tabaqui from the ''Literature/TheJungleBook'' is most likely rabid, psychotically insane, and prone to hysterical fits of laughter (so much that [[TheDreaded he is infamous throughout the Jungle]], and [[PsychoSidekick feared possibly more than Shere Khan himself]])
* Two examples from Michael Moorcock's Elric stories:
** ''The Weird of the White Wolf''. Elric wounded Yyrkoon while fighting him. Yyrkoon starts laughing, indicating his sanity had broken.
** ''The Stealer of Souls''. When Elric finally catches up to him, Theleb K'aarna has lost his mind and is tittering to himself.
* In the book ''Literature/TheHunchbackOfNotreDame'' Frollo does one when he completely loses it in the finale.
* In Creator/HPLovecraft's short stories:
** In "Literature/{{Dagon}}", the narrator begins giggling insanely after seeing the eponymous god.
** In "Literature/TheCallOfCthulhu", one of the two people who survives after seeing Cthulhu [[GoMadFromTheRevelation goes insane]] and laughs himself to death before they make it back to safety.
* In Creator/DanAbnett's Literature/GauntsGhosts novel ''His Last Command'', after they kill a Chaos stalker, Gaunt laughs and taunts the darkness with his still being alive. Ludd finds it more frightening than the stalker.
* In a variant, there's a really nightmarish scene in ''Literature/TheOdyssey'' where a character prophesizes the slaughter of Penelope's suitors by seeing them all racked with painful, hysterical laughter and choking up blood. And still continuing to laugh as they're slaughtered.
* Vera Claythorne does this in ''Literature/AndThenThereWereNone'' when she realizes U. N. Owen is enacting the bedtime rhyme and they're all gonna die.
* In Creator/RobertEHoward's "Literature/ThePoolOfTheBlackOne", while Literature/ConanTheBarbarian and Sancha are watching the [[UncannyValley inhuman]] giants who have captured their comrades, he has to slap his hand over her mouth to prevent her hysterical giggle.
* The men with no pain from the ''Literature/InheritanceCycle'' giggle madly in battle.
* [[spoiler:Bertha Mason]] in ''Literature/JaneEyre''.
* At one point in ''Literature/TheLongWalk'', a [[spoiler:DeadlyGame involving the sometimes-gory deaths of teenage boys involved in the Walk]], Garraty (the protagonist) loses it and momentarily goes Laughing Mad. It's only because [=McVries=] [[GetAHoldOfYourselfMan takes the time to get him to snap out of it]] that Garraty's fit of Laughing Madness doesn't slow him down to the point where he [[DeadlyEuphemism "buys his ticket."]]
* Rand Al'Thor in ''Literature/TheWheelOfTime'' occasionally breaks down into 'mirthless laughter' when something really terrible happens. As the series goes on, these episodes become more frequent.
* In Creator/GeneStrattonPorter's ''Literature/{{Freckles}}'', the emotional stress of his SecretLegacy coming to light causes this in Freckles.
-->''A laugh burst from him. The terrified Angel caught him in her arms and tried to stifle the sound. She implored and commanded. When he was too worn to utter another sound, his eyes laughed silently.''
* In ''Literature/ASongOfIceAndFire'', Catelyn Stark starts laughing hysterically after [[spoiler:Summer, Bran's direwolf, unexpectedly breaks into her son's room and tears the throat of an assassin who was about to kill both mother and child]]
** And she does again in the third book, ''Literature/AStormOfSwords'', after [[spoiler:she witnesses her only remaining child Robb get stabbed through the chest.]]
* In Ruth Frances Long's ''Literature/TheTreacheryOfBeautifulThings'', when Jenny definitively realizes she's in {{Fairyland}} and Jack tells her that no one will believe her, Jenny starts this. She doesn't realize it's her own for a moment after the first laugh, and it lasts a good long time. Since her brother had been swallowed up by the woods before her, she ''knows'' she won't be believed, quite thoroughly.
* In Ben Mikaelsen's ''Touching Spirit Bear'', [[TeensAreMonsters Cole]] starts laughing manically after [[spoiler: burning Garvey's shelter]]. He's not insane; this is probably because of his anger, and his DarkAndTroubledPast.
* In ''Literature/SecondApocalypse'', Sarl of the mercenary Skin Eaters company suffers a psychological break during a particularly brutal campaign. He becomes prone to cackling and shouting, "The slog of slogs, boys!" over the following weeks.
* In ''Literature/{{Pharaoh}}'' Sarah [[BreakTheCutie breaks down laughing]] when she learns that [[spoiler: Lykon murdered her baby]].
* In ''Literature/ReapersGale'', the seventh book of the ''Literature/MalazanBookOfTheFallen'', High Mage Quick Ben has a moment where he starts laughing hysterically right after he has to confront three bloodthirsty dragons head-on and all hell breaks lose. Having been reminded of all the friends he's lost over time, seeing Hedge, one of his last friends left, knocked out by a flying dragon vertebra pushes Quick Ben over the edge for the moment.
* Mr Joyful in the Literature/DiogenesClub tale "You Don't Have To Be Mad..." is a literal case, having been brainwashed to enjoy tasks that any sane person would hate. It works too well and he [[DieLaughing dies laughing]] while carrying out an assassination.
* ''Literature/WordsOfRadiance'' (second book of ''Literature/TheStormlightArchive''): More like Grinning Mad. Dalinar calls Szeth's combination of horrified, haunted eyes and gleeful grin to be the most evil thing he's ever seen.
* ''Literature/TheWanderingInn'': Tom, after being summoned with dozens of people to another world, realized that he can't fight against the demons he was supposed to fight, decided to dress up as a clown, hoping to bring others to laugh, when they all feel misery from being taken from their homes, though without much success. When the village he lives in is attacked by demons, and sees that a little boy, who he regularly interacted with, is heavily wounded,resulting in seeing him slowly dying, something snapped inside him, driving him to insanity. He starts to laugh crazily, and changes from the rather unfunny clown to a clown one is used to see in horror movies, making even the demons fear him.
* In ''Discworld/MakingMoney'', [[spoiler: Mr. Bent, who normally has NoSenseOfHumor,]] [[OOCIsSeriousBusiness cracks up laughing]] (mirthlessly at first, then manically) when his SanitySlippage reaches its peak.


[[folder:Live-Action TV]]
* ''Radio/OurMissBrooks'': "Hobby Show" ends with Miss Brooks laughing hysterically, and smearing finger paints over her face.
* Creator/ColinBaker's Series/DoctorWho went a little bit nutty after his regeneration. This was meant as a return the character's dangerous unpredictability.
** After his venture into the Time Vortex, Dalek Caan becomes the first "pure" Dalek to laugh.
** And reused over in ''"The End Of Time"'' regarding the Master. [[spoiler:All six billion of them.]]
** The Twelfth Doctor maniacally laughs when he a massive tanker smashing into a dock in ''"The Lie of the Land"''.
** The Master ends up laughing hysterically once again in ''"The Doctor Falls"''. [[spoiler:After finally dropping her internal trauma and embracing her HeelFaceTurn, taking out her homicidal past self and heading back to stand with the Doctor, [[HeelFaceDoorSlam only for that past self to shoot her in the back,]] therefore condemning her to die alone, with the Doctor never knowing what she did, [[StatusQuoIsGod because the Master will never allow himself to change]]...well, it's no wonder Missy snapped again right before the end.]] Bonus points for [[spoiler:the Saxon Master guffawing at the realization he's finally killed himself permanently.]]
* ''Series/{{Battlestar Galactica|2003}}''. Fisk, XO of the Pegasus, has a disturbing laugh that he gives after relating how Admiral Cain executed his predecessor. Fisk gives another such outburst in "Resurrection Ship", earning himself a puzzled look from everyone in CIC, who are unaware that [[spoiler:Cain had just cancelled her orders to terminate them all.]]
* Although any number of inmates in ''Series/{{Oz}}'' (such as Tobias Beecher) would qualify, probably the best example would be former prison guard Clayton Hughes after he goes insane and murders an inmate. Particularly disturbing when it happens in front of Warden Glynn, who regards him as a surrogate son.
* Victor, in ''Series/BurnNotice'', had a tendency to grin or giggle disturbingly when contemplating violence. He laughed the same way when he described why he was that way: [[spoiler:"And then the punch line, the really, ''really'' funny part was, it was [[TheHandler Carla]]. She [[DarkAndTroubledPast had my family killed]] [[ManipulativeBastard as part of my recruitment]]."]]
* Happens to John a bunch in ''Series/{{Farscape}}'' as a result of all the [[MindScrew mindscrewing]]. His tendency to inappropriate laughter is a big part of what clues his shipmates in on his SanitySlippage throughout season 2.
* Avon from ''Series/BlakesSeven''. In the season 4 episode ''Gold'', upon realizing that he and his crew had not only accomplished nothing in the episode itself despite risking their lives repeatedly, but had actually benefited the villainess, he begins to laugh hysterically under the frightened stares of the crew.
* Adrian Monk in the ''Series/{{Monk}}'' episode "Mr. Monk and the Garbage Strike" briefly went laughing mad after deciding to dump garbage trucks overflowing with garbage into the San Francisco Bay one at a time, and coming up with an insane theory about who murdered the Garbage Union Leader (it being the rock star Alice Cooper over envy over a chair) that was more or less done due to the piling garbage driving Monk completely insane, in addition to his previous theory being wrong (and for the record, the debunked theory was actually a lot closer to being correct compared to the second theory.).
* Chang on ''Series/{{Community}}''. The study group refuses to let him join even after he dances for five hours representing them in the pop and lock contest. He ends up collapsing to the floor laughing maniacally.
* In ''Series/SisterSister'', Lisa Landry was breaking out into a fit of laughter during a funeral. It's justified, however, as just beforehand, she went to the dentist, and was exposed to a large, almost lethal dose of Laughing Gas due to the dentist ranting about the person the funeral was for.
* Season 4 of ''Series/BreakingBad'' [[spoiler:Walt's reaction when Skyler tells him she gave Ted the $600,000 they needed to escape Gus, who said he would kill them all if Walt interfered by tipping off the DEA about the hit on Hank... which Saul had done on Walt's orders mere minutes before.]]
* The virus in "The Tale Of The Renegade Virus" of ''Series/AreYouAfraidOfTheDark''.
* In the movie ''Series/KamenRiderDouble Returns: Kamen Rider Eternal'', the villain of the movie tries to emotionally break Katsumi Daido, the eponymous rider. It worked a little bit too well, as Katsumi breaks down in insane laughter, followed by a CurbStompBattle with the villain on the receiving end.
* Professor Banno [[spoiler: in his incarnation as Gold Drive]] of ''Series/KamenRiderDrive'' has an ''EvilLaugh'' that veers sharply into this territory on a regular basis, as he chuckles in a somewhat subdued yet decidedly eerie manner, his head lolling at odd angles.
* ''Series/BuffyTheVampireSlayer''. In "Prophecy Girl" Buffy has a mild episode of very unsettling laughter after she overhears [[spoiler:Giles talking about her upcoming prophesied death]]. Played straight with characters who are insane: [[WithGreatPowerComesGreatInsanity Masie the invisible girl]], MadOracle vampire Drusilla, and Spike at the beginning of Season 7.
* ''Series/GetSmart''. Maxwell Smart and Agent 99 are captured by a MadScientist.
-->'''99:''' [[YoureInsane You're mad!]]\\
'''Dr Poston:''' Mad, am I??? MAAAD AM I??? MWAHAHAHAAA!!!\\
'''99:''' (''anxiously'') Don't ''do'' that!\\
'''Dr Poston:''' (''utterly straightfaced'') Don't do what?
* ''Series/{{Columbo}}'' has some murderers do this after Columbo figures them out. The most notable cases are Roger Stanford who cracked after Columbo tells him that he doesn't have the real cigarette box, and Nicholas Frame who giggles and mutters a piece of monologue from ''Theatre/{{Macbeth}}''.
* ''Series/GameOfThrones'':
** In Season 4 [[BadassAndChildDuo Sandor Clegane and Arya Stark]] arrive at the Eyrie after traveling across the war-ravaged Riverlands [[spoiler:and seeing the massacre of Robb Stark and his army just as Arya was about to be returned to her family, only to be told that the aunt Sandor hoped to ransom her to - Arya's last confirmed living relative and her only hope of being reunited with family - has also died only three days before.]] Arya's response (after a few seconds of stunned silence) is to break down in peals of laughter at the Hound for not getting his reward as [[TroublingUnchildlikeBehavior everyone stares at her in disbelief]]. Like several other incidents over the past couple of seasons, it hints at Arya's increasing SanitySlippage as she turns from heroic TomboyPrincess to [[BreakTheCutie cold-blooded killer]].
** When the "Battle of the Bastards" finally comes down to a one-on-one between Ramsay and Jon, Jon ends up straddling Ramsay's chest, pummeling him to a bloody pulp with his fists for all the hell Ramsay has done to his family and the devastation Ramsay has wreaked. After the first couple of punches, Ramsay starts laughing deliriously. After a few more punches, he suddenly ''stops'' laughing when it becomes clear that Jon is going to kill him then and there — but Jon stops when he sees his sister Sansa, who puts Ramsay awake (and smiling the best he can) in the dungeons. Then Sansa feeds Ramsay to Ramsay's own starving dogs.
* ''Series/{{Blackadder}}''. In "The Black Seal", Edmund Blackadder is trapped in a dungeon with an insane old man who laughs maniacally after Edmund asks if there's a way out. We are shown a cue card reading "[[TimeSkip Twelve Months Later]]". And the man is ''still'' laughing.
* ''Series/Babylon5'' turns a bleak scene - two mortal enemies about to die together - into an [[CrowningMomentOfFunny inappropriately hilarious]] one through this trope. In "Convictions", a bombing leaves Londo [[LockedInAFreezer trapped in a burning elevator]] with G'Kar, right after [[spoiler:he orchestrated the total defeat and violent subjugation of G'Kar's people, which has driven G'Kar to desperation and despair]]. He points out that they are likely to die if they don't work together to escape, and that, whatever their differences, G'Kar wants to live just as badly as he does. Cue AnAesop, right? WRONG! G'Kar refuses to help, and tells Londo that he doesn't want to live NEARLY as much as he wants to see Londo die, and this way he doesn't even have to do anything that would prompt retaliation - [[GallowsHumor all while giggling so hard he can barely speak]].
-->'''Londo:''' You are insane!
-->'''G'Kar:''' And that is why we'll win!
* In the season one finale of ''Series/TheGoodPlace'', Eleanor is so stunned and horrified by the realization that [[spoiler:she and the others have actually been in the Bad Place from the very beginning]] that all she can do for a good few seconds is laugh and say, "''Wow''!" She recovers pretty quickly, though.
* Lampshaded in ''Series/{{MASH}}'' episode "The Light That Failed". The characters spend the entire episode arguing over who committed the murder in a mystery novel with the last page missing. In the end Hawkeye pretends to go mad and confesses to the whole thing. He gives a mad laugh that's interrupted when he has to sign for some supplies, then takes up where he left off.

* [[Music/{{Anthrax}} "It's time for your medication, Mister Brown..." "BUHUHAHAHAHAHAHAHAHA!!!!"]]
* The end of "Music/MasterOfPuppets" by Music/{{Metallica}}.
* Just before the first guitar solo in the Music/ThinLizzy track "Chinatown".
* "Inside the Fire" by Music/{{Disturbed}} does this while combining it with the EvilLaugh; the character in which the song is being described to is most definitely going insane, but the main narrative is being told by his dead girlfriend whispering over his shoulder (who may or may not be TheDevil). In other words, it's meant to sound both crazed and demonic.
* "Afterlife" by Music/AvengedSevenfold features this in the bridge.
* Twilightning's "Rolling Heads" from the ''Bedlam'' EP ends with mad laughter.
* Heard in the end of Music/RunningWild's "Diamonds of the Black Chest" when after a lifetime of searching, the song's protagonist finds the eponymous chest. [[GoMadFromTheRevelation And it's empty]].
* Music/NapoleonXIV's "They're Coming to Take Me Away, Ha-Haaa!" It's right there in the title.
* Music/TheBonzoDogBand did a cover of "Monster Mash" that was pretty faithful to the original, until the ending, where vocalist Vivian Stanshall goes into an EvilLaugh that grows more and more manic through the fade-out.
* "Departure", the Graeme Edge poem that opens Music/TheMoodyBlues' "Ride My See-Saw", has Edge dissolving into mad laughter as it crossfades into the latter track.
* Music/PinkFloyd's "Brain Damage" from ''Music/TheDarkSideOfTheMoon''. (''The lunatic is on the grass... (laughter)'')
* Music/ThePolice's "Mother," about a man whose [[MyBelovedSmother overprotective]], constantly-phoning mother has driven him mad, ends with manic cries that turn into laughter.
* Music/DoctorSteel can be heard engaging in a mad laugh near the end of his self-titled song, "Dr. Steel."
* The end of Music/BlackSabbath's "Am I Going Insane? (Radio)" has Music/OzzyOsbourne breaking into a series of distorted, crazed laughter.
** Ozzy is quite notorious for this, to the point where many a song of his features it. It's practically his trademark.
* Arthur Brown does this a bit near the end of "Fire" as he's shouting "Burn!" over and over at the top of his lungs.
* In one version of "Beginning to look a lot like Christmas", the second chorus of 'and mom and dad can hardly wait for school to start again' is immediately followed by the female backup singers doing a not quite sane laugh just like the parents finally snapping due to holiday stress.
* Music/EbenBrooks engages in one of these at the end of his filk "Hey There Cthulhu" as the narrator finally succumbs to madness. It ends with a bloodcurdling scream as he apparently succumbs to something far worse.
* The singer of Music/PoetsOfTheFall's "[[https://youtu.be/f0w_WYXPIMc?list=PLjACqN5i5sDWU8BGL5afu1ynDxAMPX2rH Psychosis]]" opens and punctuates his bitter ranting with nasty chuckling.

[[folder:Pro Wrestling]]
* Wrestling/TerryFunk in his famous 1981 "Florida Cracker" promo.
* Wrestling/BuzzSawyer was prone to fits of it, particularly remembered is a bit during a Wrestling/KevinSullivan promo were he just starts laughing of no discernible reason and just won't stop.
* Wrestling/DanSpivey tended to degenerate into maniacal laughter when applying his [[FinishingMove sleeper hold]].
* By definition, almost every time [[Wrestling/SidEudy Psycho Sid]] burst into laughter was a case of this.
* Wrestling/HughMorrus' whole [[TheGimmick gimmick]] was based on this, starting with his PunnyName. His RedBaron was "The Laughing Man." In the Wrestling/DungeonOfDoom vignette where [[Wrestling/KevinSullivan "The Taskmaster" Kevin Sullivan]] introduced him to [[Wrestling/KingCurtisIaukea the Master]], Sullivan said that he was giving the him, "the greatest gift of all, laughter."
* Willow The Wisp in the Omega Promotion, he is but a product of Wrestling/JeffHardy's imagination, "Raaahahahaha!" He tended to laugh even when being beat up.
* During [[Wrestling/HunterJohnston Delirious]] matches where he is allowed to idle or otherwise given breathing room, he tends to talk himself and laugh.
* Tyler Bateman tends to stare off into the distance silently. When something gets his attention or he's asked to speak he'll usually let out a prolonged wheeze before degenerating into laughter.
* Wrestling/MikeyWhipwreck after joining the [[Wrestling/JamesMitchell Sinister Minister]] in Wrestling/{{M|LW}}ajor League Wrestling.
* Wrestling/{{Boogeyman}} was often laughing, particularly after singing to his hosts, spouting off poetry or squeezing the heart on his necklace.
* After Wrestling/MickieJames attacked Wrestling/TrishStratus for suggesting they should spend sometime apart, she was later found cackling over a [[StalkerShrine Trish Stratus shrine.]]
* Wrestling/{{Sting}} frequently during his "Joker" phase, as opposed to his previous and more famous stoic "Crow" phase.
* Wrestling/CodyRhodes during his "undashing phase", where his recollection of events was clearly off base. (he believed himself disfigured and thus un dashing, having to hid behind a mask, except his mask was see through so everyone could see he looked exactly the same.
* Leva Bates as the joker during her the final stages of her SHINE feud with Kimberly, going into the the "[[GimmickMatches Arkham Asylum match"]].

[[folder:Tabletop Games]]
* Numerous followers of [[TheCorruption Chaos]] in ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/{{Warhammer 40000}}'' alternate between this and EvilLaugh, sometimes combining the two for extra madness. Sort of inevitable when one allows TheLegionsOfHell to use one's skull as their metaphorical playground.
* In ''TabletopGame/{{Exalted}}'', Adorjan the Silent Wind is considered the [[DemonLordsAndArchdevils Yozi]] patron of AxCrazy. As a result, her chosen Infernals tend to get access to Charms that reflect this, such as Broken Silence Laughter Defense (which allows the Infernal to throw off attempts to influence them by laughing inappropriately) and Eloquence in Unspoken Words (which gives the Infernal telepathic communication, at the price that they can only vocalize laughter).

* In ''Theatre/SweeneyToddTheDemonBarberOfFleetStreet'', the song "Epiphany" details his DespairEventHorizon and the whole song has a lot of anguished laughter, especially the end where he declares he's "full of joy". Then comes the MoodDissonance of the next song "Little Priest", where he is really upbeat, but completely over the edge of sanity.
** Also his wife Lucy when she enters Sweeney Todd`s parlor. She lapses into a disturbing giggle before she imagines herself sitting with infant Johanna in her arms.
* Creator/WilliamShakespeare uses this one in ''Theatre/TitusAndronicus'': Titus' daughter has been raped and mutilated, his sons have been accused of the crime, and he's been told they'll be pardoned if he just chops off his hand, so he does, and when he's given his hand back along with their severed heads, he begins to laugh. And plot [[ImAHumanitarian tasty, tasty revenge.]]
* ''Electricidad'', Luís Alfaro's modern retelling of ''{{Electra}}'' ends with [[spoiler: Orestes doing this after killing Clamencia as he stumbles away from Nino, and collapses on top of the charred, rotting remains of his father's body]]. It's chilling.
* In ''Theatre/{{Wicked}}'' depending on the actress playing her (as well as the one playing Glinda), Elphaba can have shades of this when she cackles after Glinda slaps her during the cat fight scene. Bonus points if it's the exact same cackle from the film.

[[folder:Video Games]]
* [[spoiler: Wheatley]] from ''Videogame/Portal2'' has a fit of this when [[spoiler: he's attached to [=GLaDOS=]'s chassis. The programming of the mainframe drives him [[DrunkWithPower mad with power]], which causes him to become awfully sadistic. His bout of laughter also classifies as EvilLaugh, and marks his FaceHeelTurn]].
* Dr. Eggman is this [[spoiler:in the pre-final boss cutscene]] in ''VideoGame/SonicGenerations''. Lampshaded by [[spoiler:Classic Eggman. "Wow, will I really get that crazy?"]]
* Albedo in ''VideoGame/{{Xenosaga}}''. His first freak-out, back in the past, involves him [[spoiler:interfacing with U-DO]] and laughing like a maniac. Considering he looks about nine years old at the time, this is profoundly disturbing.
** Or that he's laughing while ripping himself ''apart''.
* The first sign that Alex's hold on reality in ''VideoGame/EternalDarkness'' may be none too steady is the way her sobs when she first sees her grandfather's dead body are shot through with thin veins of laughter.
** Maximillian Roivas hits this trope for brief intervals in his monster autopsy narrations, as well.
* Daniella from ''VideoGame/HauntingGround''. She does this in cutscenes in a very creepy manner and at a certain stage of insanity while chasing you.
** [[spoiler:Fiona too, in the worst ending]].
* [[spoiler:Porky Minch]] seemingly loses his mind in the final battle of ''Videogame/{{Earthbound}}'', blithely releasing the lock on Giygas (purportedly his 'boss'). This renders Giygas unable to stem the tide of his power, which threatens to consume the entire universe. [[spoiler:Porky]] addresses the player to admit he's afraid. And laughs.
** In the direct sequel ''VideoGame/{{Mother 3}}'', the team confronts a decrepit version of [[spoiler:Porky]], who has sent his robotic minion to bring forth the Dark Dragon. Until this point, it's unclear whether or not he has any idea what the Dark Dragon -- a godlike being that fulfills the heart's desire of whoever summons it -- will do if that summoner literally ''[[TheHeartless has no heart]]''. Turns out, [[spoiler:Porky]] has gradually come to the same conclusion:
--->""If the dragon wakes up, it might end up destroying everything and extinguishing all life. Even so ............[[DrunkWithPower ahaha aha ahahahahahaha!!]]"
* ''Franchise/FinalFantasy'':
** Lampshaded two times in ''VideoGame/FinalFantasyX'', first when Tidus and Yuna talk about the importance of being happy and burst onto a cheery, loud laughter with no apparent reason. When they turn around they see all others staring them with a weird look on their faces. When questioned, Wakka quietly says: "We thought that you lost your minds." Done second time in Thunder Planes, where Rikku - who's deathly afraid of thunder - keep laughing nervously as they walk, prompting Tidus to comment on it: "[[IronicEcho Heh heh, heh]]. You're giving me the creeps!"
** Kuja in VideoGame/FinalFantasyIX went Laughing Mad as soon as he learns from [[spoiler:Garland's disembodied spirit]] that [[spoiler:he'll die soon]].
** In ''VideoGame/FinalFantasyVII'', one of the first signs that Sephiroth went mad upon learning about his supposedly being the last Ancient is chuckling dementedly as Cloud/[[spoiler:Zack]] entered the lab he was researching inside.
* Adam the Clown in ''VideoGame/DeadRising'' laughs all the way through his monologue when he recalls his audience being eaten by zombies.
** After bring defeated, he laughs and falls. Onto his still running chainsaws. The laughter doesn't stop until he's dead...
*** And it doesn't just get weaker and weaker. It gets '''deeper and slower'''.
** Brent "Slappy" Ernst of ''VideoGame/DeadRising2'' also engages in this during his boss fight, such as when performing a fire spin and/or shouting things like "I'm a little teapot!"
* Very well done with ''Laughing Octopus'' in ''VideoGame/MetalGearSolid4GunsOfThePatriots''. Since she was {{mind rape}}d and turned into a psychopathic killer as a teenage girl, she never stopped laughing, even though her memories were constantly torturing her. She laughs throughout the entire boss fight and falls down laughing when she is fatally shot, making her a quite creepy encounter and not funny at all. At one very brief moment of relative clarity before dying she even says "No, nothing is funny. I shouldn't be laughing."
** Ed of Meryl's Rat Patrol 1 group, after the SOP system was locked down due to it refusing Liquid's DNA, went Laughing Mad.
* Raiden goes through this in ''VideoGame/MetalGearRisingRevengeance'' after embracing his Jack the Ripper persona prior to his battle with Monsoon. To see the previously calm and collected Raiden gleefully chop apart three enemy cyborgs after turning off his pain inhibitors is nothing short of chilling.
* Ripper Roo from ''Franchise/CrashBandicoot'' after being exposed to different experiments from Dr. Cortex became a raving, laughing, lunatic in fact after his brain was tampered with all of his dialogue consists of insane laughter with subtitles to translate.
* Father Grigori, the Zombie-slaughtering BadassPreacher of ''VideoGame/HalfLife2'' often breaks down into short bursts of maniacal laughter due to him being driven to insanity after the citizens of Ravenholm have become zombies.
* VideoGame/TheLegendOfZelda: [[spoiler:[[VideoGame/TheLegendOfZeldaTwilightPrincess Zant]] after [[VillainousBreakdown breaking down]] over the course of the battle against him.]]
* ''VideoGame/BlazBlue'' showcases Jin Kisaragi's slow descent into madness, and once he finally finds Ragna the Bloodedge, he completely snaps and starts speaking to him in a rather [[HoYay disturbing manner]]. Then there's [[WasOnceAMan Arakune]], who ends as many as half of his dialogues with raving VoiceOfTheLegion laughter. [[RobotGirl Nu-13]] doesn't seem like the laughing type, but has been known to cackle admirably on occasion. And then there's Terumi...''[[http://www.youtube.com/watch?v=bpZOhOi_-Po#t=10s god]][[http://www.youtube.com/watch?v=GTCFLikQf_8#t=14s damn]]''. All in all, the ''VideoGame/BlazBlue'' world could probably do with sedatives in the water supply.
* ''VideoGame/BreathOfFireIV'''s Fou-lu starts laughing [[spoiler:after realising that [[HumanResources Mami was used to fuel]] the Hex Cannon]], [[TheLastStraw which is what ultimately breaks him]] and decide to KillEmAll on those bastard humans.
* [[VideoGame/FatalFrame Sae Kurosawa]] ... Oh god, just thinking about it [[HellIsThatNoise makes me scared.]]
-->[[http://www.youtube.com/watch?v=HVlcJC3iNrk Ah HAHAHAHAHAHA! Eh hehehehehe! Hehehehehe... ah HAHAHAHA!]]
** Believe it or not, in the "Frozen Butterfly" ending...[[spoiler: Mayu]] manages to top it.
* Hyness from ''VideoGame/KirbyStarAllies'' is easily the most insane villain in the series to date and stresses that fact with about half of his battle noises being crazed laughter and giggles, the other half being incoherent screeching and snorting.
* [[spoiler:Revya]] from ''VideoGame/SoulNomadAndTheWorldEaters'' gets a pretty good laugh in the bad ending of the Demon Path.
* Zagi, from ''VideoGame/TalesOfVesperia''. About 50% of his dialogue is maniacal laughter, [[AxeCrazy 25% is about how much he wants to "carve Yuri's name into his blood"]], [[TalkativeLoon and the remaining 25% is utter nonsense]].
* ''Franchise/MegaMan'':
** Dr. Weil from the ''VideoGame/MegaManZero'' series qualifies, especially when taking into account the relevation of [[spoiler:his survival from Ragnarok's attack and his reaction after Zero defeated him the first time.]]
** Serpent from ''VideoGame/MegaManZX'' qualifies, considering his reaction to being absorbed by Model W's core.
*** Prometheus gets a pretty good one in Advent after he [[spoiler:kills the [[ActuallyADoombot Albert decoy.]]]]
** Zero from the ''VideoGame/MegaManX'' series (while he was still a Maverick) also had bouts of the trope, made especially apparent when he was [[NoHoldsBarredBeatdown beating Sigma to a bloody pulp when the latter was at his mercy]].
* [[spoiler:Adele]] from ''VideoGame/ArcRiseFantasia'' took finding out that she was an UnluckyChildhoodFriend [[IfICantHaveYou very]] [[FreakOut badly]].
* In ''VideoGame/CaveStory'''s BonusDungeon, the boss Ballos states that when his magic went wild and he killed everyone in the kingdom, he could only stand where he was and laugh.
* In the anarch and independent endings of ''VideoGame/VampireTheMasqueradeBloodlines'', [[spoiler:Sebastian [=LaCroix=]]] gets down with the best of them when he realizes that [[spoiler:the MacGuffin he just opened is not so much a 'gateway to infinite power' as a 'gateway to horrible burning pain' and he's been played for an UnwittingPawn]].
* Lezard Valeth from ''VideoGame/ValkyrieProfile'' should not be forgotten. [[spoiler:When he lost all his apparent sanity at the end of the game, he's [[http://www.youtube.com/watch?v=nBhksfGFiQ8 really scary]]]]. His [[http://www.youtube.com/watch?v=vNJzIVgtyAc&feature=related break mode]] is epic, too.
* In ''VideoGame/SuikodenII'', the main villain, [[AxCrazy Luca Blight]] is known to often punctuate his [[MoralEventHorizon horrific]] actions with a horse like EvilLaugh. However, when he is finally near death, he lets out a speal of insane laughter filling up more than 3 dialogue boxes that can't be classified as anything but this.
* In ''VideoGame/SuperPaperMario'', a [[EverythingsBetterWithSamurai Sammer Guy]], appropriately named Laughing X-Naut, laughs a long, loud laugh as [[spoiler:the Void in his dimension fully matures, destroying his entire universe. He laughs all the way until his inevitable annihilation]].
* Iggy Koopa, one of the Koopalings, is depicted as Laughing Mad in ''VideoGame/NewSuperMarioBrosWii''. Given that the (English) post defeat narrative on Iggy in ''VideoGame/SuperMarioWorld'' described him as "[[AxCrazy demented]]," this shouldn't come as a surprise.
* In ''VideoGame/CityOfHeroes'', one of the EnemyChatter for the [[AnarchyIsChaos Freakshow]] is simply a manic laugh, which was demonstrated by one Freak in the original trailer.
* If [[VideoGame/FatalFury Yamazaki]] is feeling jovial, you know the walls are about to be painted red.
* Kubikiri Basara from the VideoGame/SamuraiShodown series. His post-mortem insanity has him hunting down Minazuki Zankuro and giggling all the way.
* Ribsmasher, a [[AxCrazy batshit insane]] monk in ''VideoGame/NeverwinterNights2: Storm of Zehir''[[note]]He made a couple brief appearances in the original campaign but turned into an AscendedExtra in the second expansion.[[/note]] In [[LargeHam literally every line he has large chunks of scenery get chewed]], and they all involve raucous laughter and/or smashing ribs.
** The [[AxCrazy Manic Psychotic voiceset]] does this a lot as well. Including when he ''dies'', which takes the usually hilariously hammy voicing into creepy territory
* In one Franchise/CthulhuMythos based {{MUD}} the status of your SanityMeter is represented by various adjectives, with the adjective varying depending upon how high or low it is. Well, except for when your sanity hits rock bottom. At that point the adjective is replaced by "HAHAHAHAHA!!!", with each "HA" [[PaintingTheMedium being a different color]].
* In ''VideoGame/TelepathTactics'', ClimaxBoss Archos does this as part of his LastWords.
* ''VideoGame/DawnOfWar'': Chaos Space Marines and Imperial Guard Psykers are inclined towards fits of raucous laughter audible to enemies as the Warp seeps in and out of their brain. The psykers, by the way, are with the good guys.
* ''VideoGame/AlanWakesAmericanNightmare'' has Music/PoetsOfTheFall's "[[https://youtu.be/BAh6ay9QDtE?list=PLjACqN5i5sDUEienDV52g85W6J7chzLXV The Happy Song]]," the VillainSong of SerialKiller Mr. Scratch, wherein an AxCrazy singer punctuates his open admissions that he's "a psycho" with husky chuckles or shrieky laughter depending on whether his EvilGloating takes the form of a mock-conspiratorial whisper or an enthusiastic scream.
* Common in ''VideoGame/{{Borderlands 2}}''. Goliath enemies who've [[BerserkButton had their helmets shot off]] will butcher their teammates while laughing uproariously, while playable Psycho Krieg, who has grave difficulty interacting with the world in non-buzz-axe ways, has quite the selection of deranged laughter himself.
* The Jester class in ''Videogame/DarkestDungeon'' will go from TheHyena to this trope if he undergoes an affliction, as he clearly goes off his rocker by laughing constantly and/or being interrupted with sobbing.

[[folder:Visual Novels]]
* In the ''Franchise/AceAttorney'' series, [[spoiler:Luke Atmey]] and [[spoiler:Kristoph Gavin]] laugh disturbingly upon defeat, possibly to indicate madness (they're both pretty crazy). [[spoiler:Damon Gant]] gets [[http://www.youtube.com/watch?v=rkb_svMvYVQ#t=12m49s the most epic one]], however: [[spoiler:he claps as he laughs, and as the laugh revs up, his hands slam together so quickly they throw off ''sparks''!]]
** The tradition continues in ''VisualNovel/AceAttorneyInvestigationsMilesEdgeworth'', where [[spoiler:the killer of case four, Calisto Yew,]] ends up doubled over laughing by the time he/she is done... [[spoiler:and then shows just how sane she is by pointing out Edgeworth just accused her of murder... in a case [[OhCrap where one of the pistols is still missing]].]] And then [[spoiler:case five happens]] and holy hell is [[spoiler:Shih-na's breakdown]] some quality horror.
** A non-villainous example is Lotta Hart from ''Justice For All''. She thinks that the crime scene will be her one big break and starts laughing crazily as she runs to it. Even Phoenix got scared when that happened.
* ''Visual/NineHoursNinePersonsNineDoors'':
** [[spoiler:Ace/Hongou]] is revealed to have done this [[spoiler:when he locked Akane in the furnace to force her to use morphogenic fields to survive.]]
** He does the same thing when confronted as the villain in the Safe ending.
* Beatrice in ''VisualNovel/UminekoWhenTheyCry'' [[InvokedTrope does this intentionally]] to unnerve opponents (which is probably where Maria learned her own creepy laugh,) and is quite at ease when laughing mad. This is in contrast to Erika, who laughs more madly when under more pressure, up to and including full VillainousBreakdown.
* In ''VisualNovel/DanganRonpa'', [[spoiler: Genocide Jill (AKA Toko Fukawa's murderous alternate personality)]] is usually this when they're not fawning over [[spoiler: Byakuya]].
** ''VisualNovel/SuperDanganRonpa2'' gives us [[spoiler: Nagito Komeada]], with no less than three instances of this: their VillainousBreakdown in Chapter 1, their discovery of [[spoiler: the Funhouse's secret weapon in Chapter 4]], and after [[spoiler: blowing up the hotel to weed out the traitor in Chapter 5]].

[[folder:Web Animation]]
* Flippy of ''WebAnimation/HappyTreeFriends'' whenever he goes into AxCrazy mode. Also, the hyperactive squirrel, Nutty.
* ''WebAnimation/HomestarRunner'': Strong Bad goes into a rather creepy mad laughing fit in the Sbemail "isp" after discovering that Strong Mad has screwed up his Internet connection by [[ItMakesSenseInContext literally sucking up bandwidth]].
* ''WebAnimation/{{Dreamscape}}'': As part of Ethan's [[ObfuscatingInsanity insanity act]], this is a given.

[[folder:Web Comics]]
* [[spoiler:Rachel]] at the end of the Knot of Wool arc in ''Webcomic/TowerOfGod''.
* According to the story hidden in [[spoiler:the filenames]] of ''Webcomic/{{Narbonic}}'', this is how Helen went mad:
-->[[spoiler:''She laughed hysterically for a minute or so. Not a good sign, she thought. And then the thought fluttered away. Her face, when it skipped into focus, was pale and blotchy. Possibly she had been crying. Yes, someone had definitely been crying sometime. Not her. Not when everything was so funny and she had so many interesting ideas...'']]
* Ellen in ''Webcomic/ElGoonishShive'' does one of this, complete with a line that goes behind a character's head to show they've snapped when she is first brought into existence, and she thinks that she'll die in a month. [[http://www.egscomics.com/?date=2002-08-01 The comic title says it all]]. She then decides to become Elliot's {{evil|Twin}} [[CardCarryingVillain twin]], which she's... [[HarmlessVillain not too good at...]]
-->'''Tedd:''' ''[[[GenreBlind not too Genre Savvy]]]'' Oh good! She's laughing!
* [[spoiler:Sandra Eastlake]] in ''Webcomic/ZebraGirl'', [[http://www.zebragirl.net/?date=2007-05-26 just after her heroic BSOD/Face Heel Turn.]]
* When Computer returns to perform horrifying acts of vengeance against the [[http://www.jaydenandcrusader.com J&C]] cast she is always seen grinning madly, though not laughing.
* Valentino descends to this after being tricked into [[DeadlyGraduation killing her one and only friend]] from her TrainingFromHell during a side/[[StartOfDarkness origin story]] in the comic [[http://www.marilith.com/archive.php?date=20070712 Marilith.]]
* Rocky and Freckle in ''Webcomic/{{Lackadaisy}}'', mostly whenever they're either cheating death or dealing it.
* Jane Unpleasant in ''Webcomic/EverydayHeroes'' [[http://eheroes.smackjeeves.com/comics/2133682/ch14-04/ enjoys a chuckle.]]
* Hyde from ''Webcomic/TheSearchForHenryJekyll'' cackles hysterically after killing his first victim.
* Cake Girl from ''Webcomic/{{Gloomverse}}'' tends to randomly burst into laughter.

[[folder:Web Original]]
* In the ''VisualNovel/DanganRonpa''/''[[Manga/{{Doubt}} Rabbit Doubt]]'' hybrid ''Roleplay/DoubtAcademy'', [[spoiler:Akari Kagome, the Super High School Level Hockey Player, has one of these when she realizes she's going to be executed for a murder she didn't commit.]]
* ''WebVideo/DoctorHorriblesSingAlongBlog'': Dr. Horrible starts out maniacal laughing because he's GenreSavvy, and then does the laugh again because it's situationally appropriate. Even though we see his SanitySlippage happening immediately in the next song... we never see him laugh again. It's almost like he went sane.
* WebVideo/EverymanHYBRID, "Joke's Over" - Evan, on seeing what was inside the garbage bags hung up by the Slender Man. He hadn't completely snapped yet, but this was probably one of the first warning signs.
* [[MadScientist Dr. Insano]] of ''WebVideo/AtopTheFourthWall'' and ''WebVideo/TheSpoonyExperiment'' is prone to this.
* ''WebVideo/TheNostalgiaCritic'':
** At the end of his review of ''Film/TheNeverendingStory 3'', the Critic starts laughing nonstop as he leaves his house, drives to a Home Depot to pick up a crowbar, and heads back home. He stops laughing when he smashes up the DVD, [[WebVideo/TheAngryVideoGameNerd AVGN]]-style.
** He does it again in the ''Master of Disguise'' review, where he responds to a "funny" joke by flipping out, laughing insanely, and beating three people with a baseball bat.
--->'''Critic:''' ...Where was I for the last two minutes?
** [[Creator/DougWalker Doug]] himself has a tendency to do this, annoying Rob in the ''Film/ManOfSteel'' Sibling Rivalry and painting himself as TheWoobie in the first ''WesternAnimation/AdventureTime'' review.
* ''WebVideo/OneHundredYardStare'': Ellie goes laughing mad for a moment in episode five. And later several times, also this is her basic mode in season two.
* The ending of the ''LetsPlay/TwoSaiyansPlay'' of ''VideoGame/{{Outlast}}'' has Krillin laughing maniacally. This was in the official, re-recorded version.
* The Website/{{YouTube}}r WebVideo/TheOrangeInsanity slowly but surely starts [[http://youtu.be/yN3PFkJgrHM?t=36m34s laughing maniacally]] in his review of ''Film/TheLastAirbender'', before going into CryLaughing after seeing the scene in which [[spoiler:the dragon tells Aang that the Avatar is not meant to hurt others.]]
* LetsPlay/{{Turpster}} falls into this when he plays either as the titular character in ''VideoGame/TheHidden'', or as the murderer in ''VideoGame/GarrysMod Murder'', and decides to [[DrunkOnTheDarkSide ham]] [[EvilIsHammy it]] [[EvilLaugh up]].
* Poor LetsPlay/{{slowbeef}}. In his ''VideoGame/SonicTheHedgehog2006'' Let's Play on the WebVideo/{{Retsupurae}} channel, after losing his last life in Silver's version of the Kingdom Valley level, he realises that the last time he'd saved was over an hour in the past, meaning that he'll be forced to replay the sections with [[EscortMission Anna]] and the LetsPlay/ProtonJon [[ItMakesSenseInContext priests' tests.]] Upon this realisation, [[https://www.youtube.com/watch?v=q5orzCJcBtM&t=19m25s all he could do was burst into laughter,]] while LetsPlay/{{Diabetus}} could only utter a FlatWhat.
* [[WebVideo/AtopTheFourthWall Linkara]] did this himself in his ''WebVideo/HistoryOfPowerRangers'' review detailing ''Series/PowerRangersMegaforce'', as his reaction to [[spoiler:Robo Knight's UnexplainedRecovery]], cutting to video of him laughing as he grabs a gun, walks off, empties the clip, and his laughing turns to screaming.
* [[WebVideo/SomeCallMeJohnny The Super Gaming Bros.]] had a moment in their multiplayer ''VideoGame/SonicTheHedgehog2006'' playthough. Elliot dies to three meteors in a row; [[https://www.youtube.com/watch?v=kHabbKNkvFo causing Matt to laugh himself insane]].
* [[HeroicComedicSociopath Kirito]] falls into this a few times in ''WebVideo/SwordArtOnlineAbridged'', first when Rosalia gives him a BreakingSpeech that slams ''several'' of his {{Berserk Button}}s, and later when he [[ExtremeMeleeRevenge says "hi"]] to Gary, an NPC whose ArtificialStupidity got Kirito's first real friend killed.

[[folder:Western Animation]]
* [[spoiler:Azula]] in the series finale of ''WesternAnimation/AvatarTheLastAirbender'', during a schizo FreakOut.
* In ''WesternAnimation/TheSpectacularSpiderMan'', when [[spoiler:Harry Osborn thinks that he was blacking out and becoming the Green Goblin]], one of his many reactions, besides depression and anger, is semi-maniacal chuckling.
* Another Spider-Man Example. In fact, another Harry Osborn example. In the [[WesternAnimation/SpidermanTheAnimatedSeries 90's Spider-Man show]], when Harry finds out that The Green Goblin [[IAmYourFather was his father]], he goes into a laughing fit (his mind wasn't too stable at the moment, he was talking to his father's ethereal head from another dimension and all that... long story...) and then decides to "fulfill his destiny" and become the second Goblin.
* [[AxCrazy Ren]] of ''WesternAnimation/TheRenAndStimpyShow'' is often portrayed as this.
** Most extreme cases include when he was under the effects of the happy helmet (complete with a full set of grimaces), and when he was beating George Liquor up with an oar in a banned episode, "Man's Best Friend".
* In one episode of ''[[WesternAnimation/CareBearsAdventuresInCareALot Adventures in Care-a-Lot]]'', a sleep-deprived Bedtime is portrayed this way.
* In ''WesternAnimation/TheBatman'''s Harley Quinn episode, the way the viewer can tell that Harley's returned sanity is fleeting is when she starts laughing maniacally.
* ''WesternAnimation/BatmanTheAnimatedSeries'': The Demon's Quest, when Ra's al Ghul comes out of the Lazarus Pit.
** [[http://www.youtube.com/watch?v=lb8fWUUXeKM Any time the Joker laughs]].
** Then there's Jack Ryder, who as the Creeper giggles like a stoner watching [=YouTube=].
* At the end of ''WesternAnimation/BatmanBeyond'''s first episode, when CorruptCorporateExecutive Derek Powers sees that he has transformed into a glow-in-the-dark radioactive skeleton man, his immediate reaction is to begin laughing maniacally. The doctors are appropriately freaked out.
** Coincidentally, he reacted to his new appearance in a manner that is eerily similar to the Joker from the 1989 Batman film under eerily similar circumstances.
** There's also the brief moment where Ian Peeks [[spoiler:realizes, with [[IntangibleMan his torso phased through the basement floor]] and with Batman unable to grab him and pull him out, that he's beyond saving. He goes down laughing and screaming until he fully sinks below, [[AndIMustScream presumably realizing he'll be stuck beneath the earth until he dies]]]].
** In ''WesternAnimation/BatmanBeyondReturnOfTheJoker'' Tim does this after being BrainwashedAndCrazy by ComicBook/TheJoker and Harley. It's pretty damn creepy.
* Averting this in ''WesternAnimation/BatmanTheBraveAndTheBold'' is central to Earth-23's Red Hood. When Owlman pushed Jack Napier into the Ace Chemical Plant vat, Napier's skin was bleached, his hair turned green, and his lips became bright red. When Napier returned home, he sat in front of a mirror, looked at himself, and began to laugh... [[RageAgainstTheReflection before smashing the mirror]]. It was at this point he began his vengeful crusade with other hero as Justice Underground against the tyrant Owlman and his Injustice Syndicate of Amerika.
* WesternAnimation/LooneyTunes - WesternAnimation/DaffyDuck.
* ''WesternAnimation/EdEddNEddy'': Eddy does this in "Little Ed Blue" after realizing why [[BewareTheNiceOnes Ed was angry and antisocial all day.]] [[spoiler:There was a pebble in his shoe.]]
** In "Cleanliness is Next to Edness", [[NeatFreak Edd]] goes insane after failing to find a place to bathe and getting dirtier with every attempt. He snaps out of it, eventually.
* [[WesternAnimation/TheSimpsons Lisa Simpson]] briefly went Laughing Mad when seeing her new braces in the episode ''Last Exit To Springfield'', of which it was a direct homage to Jack Napier's reaction to his new appearance due to botched reconstructive surgery ''and'' falling into the vat of chemicals.
** [[https://www.youtube.com/watch?v=jgflCE7zRpc When Sideshow Bob ran for mayor and won, he burst into a maniacal laugh.]]
--> '''Kent Brockman:''' [[DevilInPlainSight And look how happy he is!]]
** Homer, after a [[ItMakesSenseInContext trampoline pushes him over the edge]], tries and fails to destroy it with a circular saw.
-->'''Homer''': Alright, alright, you win for now. But someday you'll RUST! ''[[SanitySlippage RUST,]]'' [[SanitySlippage I TELL YOU]]! ''[Descends into deranged, maniacal laughter]''
** Also one of the show's Halloween episodes, which features a certain painting, the mere glimpse of which drives people mad:
-->'''Homer''': They're dogs, and they're ''playing poker!'' ''[Screams, more deranged laughter.]''
* On ''WesternAnimation/JimmyTwoShoes'', when Lucius suffers a VillainousBreakdown, he begins laughing wildly before completely cracking.
* Hexadecimal from ''WesternAnimation/ReBoot'' enjoys her {{evil laugh}}ter, but, being pretty crazy, she tends towards Laughing Mad on more than one occasion. Then she becomes outright ''insane'' in season 3, due to a combination of [[spoiler:being nearly destroyed in an explosion and subsequently rebuilt, her [[WhiteMaskOfDoom mask]] becoming cracked, and being [[ColdBloodedTorture tortured and used as a weapon]] by Megabyte.]] After this, pretty much ''every time'' she laughs is an example of Laughing Mad. (At least, until [[spoiler:Bob defragments her head]].)
* ''WesternAnimation/SpongebobSquarepants'' during the season 4 episode Bummer Vacation. "I've been WAITING for you Patrick!"
** Squidward during the episode "Squid's Day Off" after he goes crazy from paranoia as he's nailing his door shut.
* Fluttershy in the ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' episode "The Best Night Ever".
** Twilight Sparkle as well, in "Lesson Zero".
** Nightmare Moon, [[http://www.youtube.com/watch?v=RAp8DFBb7XM arguably]].
** Spike's turn: "Owl's Well That Ends Well".
* In ''WesternAnimation/FamilyGuy'' Meg is sometimes portrayed as deranged or disturbed out of [[DesperatelyCravesAffection a desperation for love and attention]]. In one scene Chris asks her what kind of gifts boys have gotten for her and she describes imaginary gifts given to her by her imaginary boyfriend prince William before laughing crazily and running out of the room in tears.
* ''WesternAnimation/InvaderZim'', being rather AxCrazy, has moments like this.
* In ''WesternAnimation/AdventureTime,'' we have Lemongrab's utterly disturbing laughing fit in Too Young. He doesn't even SMILE- his head just flails around and bounces with weird squishy noises, and his eyes are wide.
--->'''Lemongrab:''' "...Prank? F-for laughs? Yes, of course; just a harmless prank... F..for laughs... Ha..a.a? HAHAHAHAHHAHAHAHAH-OH! HAHHAHOAHAOHAOAHOAHAOAHAHAOAOAAHAOAHAOAHAOA-" *immediately returns to normal* "Twelve years dungeon! All of you- DUNGEON! Seven years, no trials! C'mon... LET'S MOVE IT!!!"
** He comes by it honestly; his mother Princess Bubblegum reacted similarly to the prospect of Finn bringing the [[SitcomArchNemesis Duke of Nuts]] to justice. "The justice... of a COLD DUNGEON! MWAHAHAHA-AHAHAHAHAAHAAA!!!" Jake Lampshades the moment by saying with an awkward laugh, "She's completely ''bonkers''."
* In ''WesternAnimation/TeenTitans'' "Nevermore" when Robin and Starfire go onto the roof of Titans Tower to tell Raven about her door being broken down, she breaks out into hysterical laughter which sounds just like something out of VisualNovel/HigurashiWhenTheyCry, then she just abruptly stops and goes inside.
* Stu of ''WesternAnimation/{{Rugrats}}'' does this during his SanitySlippage moment in the episode "Angelica Breaks A Leg."
* In ''WesternAnimation/{{Wakfu}}'' season 2 episode 20, [[spoiler:Qilby goes completely nuts after merging with the Eliacube]] and laughs maniacally during his TeleportSpam at the tail-end of his fight with [[spoiler:Adamai]].
* The animated adaptation of ''Discworld/WyrdSisters'' has Felmet going more and more insane, and as he slips further off the slippery slope he sure lets out a lot of maniacal laughing.
* ''WesternAnimation/StevenUniverse'': In "Log Date 7 15 2", having [[HeelFaceTurn just committed treason against Homeworld]] by disobeying and [[DidYouJustFlipOffCthulhu insulting Yellow Diamond]], [[spoiler: Peridot is having the FreakOut of a lifetime, alternating between fits of horror and fits of manic giggling while replaying the phrase "traitorous clod" over and over again on her tape recorder. When Steven asks if she'll be okay, she turns around with a manic grin and delivers an equally deranged [[BluntYes "No!"]]]].
* In an episode of ''WesternAnimation/DuckDodgers'', Marvin removes Dodgers' brain and attempts to link his own brain to it to learn Dodgers' secrets. The machinations of Dodgers' subconscious drives Marvin to madness, resulting in this.
* The ''WesternAnimation/CourageTheCowardlyDog'' pilot short ''WesternAnimation/TheChickenFromOuterSpace'' has Eustace break into insane laughter when he starts turning into a chicken.

[[folder:Real Life]]
* In the famous [[http://en.wikipedia.org/wiki/Milgram_experiment Milgram Experiment]], which was meant to test how far normal people would go when obeying the orders of someone in a position of authority[[note]]the experiment involved the participant quizzing another individual, who is to pretend that he is receiving painful electric shocks with each wrong answer; the participant is led to believe that the shocks are real[[/note]], one of the subjects, an encyclopedia salesman, went into fits of hysterical laughter when he heard the screams of pain from his supposed victims, to the point where the session had to be discontinued. He wasn't a sadist, or insane; the laughter was just an indicator of the extreme emotional stress he was under.
* There's a condition called Pseudobulbar Affect, in which the patient loses the ability to regulate emotional expression. They may collapse into a sobbing heap at the sight of a kitten, show absolute terror at their loved ones or laugh hysterically and uncontrollably at the loss of something dear to them. This is involuntary.
* According to legend, UsefulNotes/{{Nero}} was laughing [[WhileRomeBurns while watching Rome burn]], though we only have his enemies' word on this. It's unclear whether he was even in the city at the time.
* According to Suetonius,[[note]]see the above caveat about Nero[[/note]] [[UsefulNotes/{{Caligula}} Caligula]] once broke into a laughing fit at a banquet. When two of the guests asked him what he was laughing about, the emperor said, "What do you suppose, except that at a single nod of mine both of you could have your throats cut on the spot?"
* Music/JohnLennon broke down into hysterical laughter upon hearing that his friend Stu Sutcliffe had died. He did the same thing after his mother had passed away.
* Many people use laughter as a defense mechanism, in order to deal with some terrible thing.
* Shellshocked veterans after UsefulNotes/WorldWarI happened to laugh madly in some cases. One soldier discharged from the US army, broke down laughing for most of his remaining life, after being ordered to drive his tank over soldiers who were NotQuiteDead. That experience led to a complete breakdown and a veteran locked away LaughingMad.
* There are some cultures that use laughter as a means of dealing with emotionally heavy moments, e.g. Australia and the UK, which can seem like this trope to those unfamiliar with this.
* This trope is one of the things that led to the HeinousHyena stereotype. Hyenas make a sound very similar to human laughter when stressed, which made humans assume they were evil, eerily human-sounding creatures laughing maniacally as they ripped prey apart.