History WesternAnimation / TreehouseOfHorror

** [[Recap/TheSimpsonsS34E5NotIt Treehouse of Horror Presents: Not It]], a full-length Treehouse of Horror special produced in addition to Treehouse of Horror XXXIII.

* OddballInTheSeries'': "Treehouse Of Horror II" is the only "Treehouse Of Horror" special where the individual segments don't have onscreen titles. In this episode, the FramingDevice is Lisa, Bart, and Homer having candy-induced nightmares, so the episode guide only refers to the segments as "Lisa's Nightmare", "Bart's Nightmare", and "Homer's Nightmare".

* ParodyAssistance: One for the comics: one issue tells the story of Homer becoming a terrible blob creature made out of Squishee drink, in a very obvious Swamp Thing homage (""Squish Thing''). So who did they get to write and draw said story? Len Wein and Bernie Wrightson, the duo who created Swamp Thing to begin with!

Not to be confused with ''[[Recap/TheSimpsonsS31E8ThanksgivingOfHorror Thanksgiving of Horror]]'', a ''[[ThanksgivingEpisode Thanksgiving]]'' episode formatted like a ''Treehouse Of Horror'' episode, or ''[[Recap/TheSimpsonsS27E4HalloweenOfHorror Halloween of Horror]]'', the only canonical HalloweenEpisode of ''The Simpsons''.

Many of the tales feature {{Affectionate Parod|y}}ies of contemporary HorrorFilms and ''Series/TheTwilightZone'' episodes. Others are inspired by more traditional horror -- there is even a DramaticReading of Creator/EdgarAllanPoe's "Literature/TheRaven" in the first "Treehouse" episode.

* TheDollEpisode: In "Treehouse of Horror III", Homer gets Bart a cursed Krusty doll from a Chinese man's curio shop filled with cursed and weird objects from around the world.
** But it comes with a free frogurt![[note]]That's ''good''![[/note]]
** The frogurt is also cursed.[[note]]That's ''bad''.[[/note]]
** But you get your choice of topping![[note]]That's ''good!''[[/note]]
** The toppings contain potassium benzoate. [[note]]...[[spoiler:That's ''bad''.]][[/note]] [[note]]Can I go now?[[/note]]
*** And the doll [[spoiler:wasn't even cursed, despite coming from an occult curio shop run by a strange Chinese man. The doll had a "good/evil" switch on its back that someone flipped on "evil"]].

Many of the tales feature {{Affectionate Parod|y}}ies of contemporary HorrorFilms. Others are inspired by more traditional horror -- there is even a DramaticReading of Creator/EdgarAllanPoe's "Literature/TheRaven" in the first "Treehouse" episode.

* AbnormalLimbRotationRange: Done in "Treehouse of Horror XVI", in a {{parody}} of / ShoutOut to ''Film/TheExorcist''. A possessed Homer climbs on the wall and ceiling, and rotates his head around 180 degrees. When Marge says she'll call Mr. Burns that he can't go to work, he falls back on the bed in success, with his head still backwards.
** In "Treehouse Of Horror I", Maggie turns her head around 360 degrees while looking for a knife.

* AdaptationalVillainy: Frequent; depending on the requirements of the short you'll see Skinner go from DeanBitterman to a student-eating cannibal, Bart's troublemaking ramped up to EnfantTerrible-level criminality or Marge as the EvilMatriarch of the local vampire population.

* ComedicSociopathy: These specials take the show's more moderate BlackComedy and crank it UpToEleven, with the main cast regularly maiming and killing each other at whim for gags. Of course it's all reset by the next segment.

* IdiotBall: {{Justified|Trope}} in order to both tell these episodes from the main canon (which still has a lot of Idiot Ball, [[UpToEleven just not to this extent]]) and [[AnyoneCanDie rack up a big body count]] (with Groundskeeper Willie being [[TheyKilledKennyAgain this side of Kenny McCormick]] in the fifth special), which in turn also tells the halloween episodes apart from the canonical ones.

** ''XXI'' contains one directed at the TabletopGame ''TabletopGame/MouseTrap'', in which a parody called "[[ParodyNames Mouse Catch]]" is referred to as "the game so lame no one's ever finished it".

* TheManyDeathsOfYou: Occasionally, a ''Treehouse'' segment will experiment with how many times a character can be killed, then brouught back, in the same story. Bart ("Wanted: Dead, Then Alive"), Homer ("Heaven Swipes Right"), and Lisa ("Be Nine, Rewind") all get this treatment at different points, but each manage to come out with a SurprisinglyHappyEnding.

* LosingYourHead: Homer in "Treehouse of Horror XVI"

** Many of the shorts only have a passing connection to horror, often exploring sci-fi, action, political thrillers and fantasy genres that barely include a Halloween theme. The only thing keeping them from being a regular episode is a willingness to have crazier endings [[KillThemAll like everyone dying]].

* KillEmAll: If the fates of all Springfieldians are in the balance, guarantee their survival may be a crapshoot. [[TheEndOfTheWorldAsWeKnowIt "Life's A Glitch, Then You Die"]], [[StuffBlowingUp "The Ned Zone"]], [[NukeEm "The Homega Man"]], [[HuntingTheMostDangerousGame "Survival of the Fattest"]], “Dry Hard”, “Night of the Dolphin”, “Homerzilla”, “It’s The Grand Pumpkin, Milhouse”, and “Dial Z for Zombies” are shining examples. Also a literal crapshoot in “War and Pieces,” since everyone gets sucked into a board game.

* NotInTheFace: The "Treehouse of Horror XV" segment, "The Ned Zone", has Flanders seeing a future in which he kills Homer.
--> '''Lisa''': Well, you can't fight fate. But if you must shoot our father, please remember our family motto, "Not in the face."

* LighterAndSofter: Oddly enough, this does happen on occasion, like in ''Homer³'', ''[[Literature/TheIslandOfDoctorMoreau The Island of Dr. Hibbert]]'', and ''War and Pieces''.

* HorrorDoesntSettleForSimpleTuesday: Mostly averted. Outside of the wraparounds, which are ''all'' set on Halloween, most stories could theoretically take place on any random day of the year. There are few exceptions, including ''I've Grown A Costume on Your Face'', ''Heck House'', ''It's the Grand Pumpkin, Milhouse'', ''The Diving Bell and the Butterball'', and ''Oh, the Places You'll D'oh''[[note]]Halloween[[/note]], ''Citizen Kang''[[note]]The week leading up to America's Election Day, which ''coincidentally'' includes Halloween[[/note]], ''Easy Bake Coven''[[note]]Which, InUniverse, retroactively ''created'' Halloween[[/note]], ''Life's a Glitch, Then You Die''[[note]]New Year's[[/note]], and ''Untitled Robot Parody''[[note]][[TwistedChristmas Christmas]][[/note]].

* HalloweenEpisode: The annual "Treehouse of Horror" episodes, every year since 1990. The creators have mentioned that they actually wish they could stop doing these, or at least wish they could change the anthology format, but that it became such an iconic part of the show that they felt they had no choice but to continue. They're PlayedForLaughs... [[NightmareFuel most of the time.]]

** Season 27's "[[Recap/TheSimpsonsS27E4HalloweenOfHorror Halloween of Horror]]" was notable for bucking tradition and be an ACTUAL HalloweenEpisode that was intended to be part of the show's canon, and they playfully mention the "scary treehouse stories". The next episode was a normal "Treehouse Of Horror" installment.

* SomethingCompletelyDifferent: Some recent "Treehouse of Horror" take a break from horror stories and focus on science-fiction or comic books, or [[UpToEleven fairy tales]], with a darker spin...

* JuryOfTheDamned: "Treehouse of Horror IV" ("The Devil and Homer Simpson" segment), when Homer sold his soul for a doughnut, included a jury consisting of John Wilkes Booth, Lizzie Borden, John Dillinger, Blackbeard, Benedict Arnold, [[ArsonMurderAndJaywalking the starting lineup of the]] [[OpposingSportsTeam 1976 Philadelphia Flyers]], and UsefulNotes/RichardNixon (who, at the time of the show's premiere, was still alive, making this dialogue a mix of FunnyAneurysmMoment and HilariousInHindsight):

These are ''WesternAnimation/TheSimpsons''[='=] special annual {{Halloween Episode}}s. Earlier installments have the onscreen title of ''The Simpsons Halloween Special''. Every season but the first one has had one.

* LooseCanon: In general, ''Treehouse of Horror'' is treated as an {{Elseworld}}, separate from ''The Simpsons''' normal universe. But sometimes the line between canon and non-canon can get blurry, and certain ''Treehouse'' elements can bleed over into the regular series, and will be treated as though they were already there to begin with. Indeed, Kang and Kodos, the German exchange student Uter, and the Lard Lad mascot all ''started'' as [[CanonForeigner canon foreigners]], but later found their way into ''The Simpsons'' proper and became [[CanonImmigrant canon immigrants]].