History Recap / TheSimpsonsS30E4TreehouseOfHorrorXXIX

* OOCIsSeriousBusiness: PlayedForDrama. Bart and the others become confused that his little sister, the vegan and SoapboxSadie of the family, kidnapped them, chained them up, and threatens to murder them. As Lisa prepares to murder him, Bart whispers, "What happened to you?"

* SanitySlippage: Lisa suffers through this ''big time''. Bart altered her test, resulting in her receiving in a failing grade.
* ShoutOut:

* TookALevelInJerkass: Bart usually prefers to see Lisa fail on her own merit. Here he intentionally went out of his way to make sure she got an F.

* StealingTheCredit: Frink's assistants beat him for being a credit hog. Him saying he mentioned them in the footnotes does not mollify them.
* TakeThat:

* KarmaHoudini: Lisa gets away with her actions, justifying the whole experience as a stress reaction to Marge. Miss Hover gives Lisa an F in spite of having realized the test had been tampered with and never receives any commeupance.

* KarmaHoudini: Millhouse and Nelson are transformed and killed respectively, but Bart, who actually instigated the plot, manages to talk down Lisa (although not before being terrified out of his wits and nearly killed). Lisa likewise gets away with her actions, justifying the whole experience as a stress reaction to Marge. Miss Hover gives Lisa an F in spite of having realized the test had been tampered with and never receives any commeupance.

* MyGodWhatHaveIDone: Despite his KarmaHoudini status, Bart looks horrified and guilty on realizing that he caused his sister's psychotic break and manages to talk her down by saying he'll be there for her in the future. Relatedly, Lisa is visibly sickened by what her alternate personalities want to do to Bart.

* CallBack: This is the second episode with an alien invasion orchestrated by impersonators of authority figures, the first being about the 1996 election.

* YourSizeMayVary: Pterosaur!Agnes was only slightly larger than a human throughout most of the skit. At the end, she's suddenly grown big enough to carry a helicopter (with the Simpsons boarding it) on her back.

* PteroSoarer: Agnes as a pterosaur, possibly a ''Ludodactylus'', is bipedal and tries to eat people (namely the arms of her own son).

This year's Halloween special sees Homer face off against H.P. Lovecraft's Cthulhu in an eating contest, a strange plant turning the people of Springfield into slaves, Bart and Milhouse at the mercy of Lisa's multiple personalities, and The Simpsons vacationing at a ''Jurassic Park''-esque wildlife refuge.

* StockDinosaurs: ''Stegosaurus'', ''Brachiosaurus'', ''Iguanodon'', ''Parasaurolophus'', ''Compsognathus'', ''Tyrannosaurus rex'', ''Triceratops'', ''Pachycephalosaurus'', ''Ankylosaurus'', ''Dilophosaurus'', ''Velociraptor'', ''Allosaurus'', ''Apatosaurus'', and ''Mosasaurus'' are among the genera the seniors transform into.

This year's Halloween special sees Homer face off against H.P. Lovecraft's Cthulu in an eating contest, a strange plant turning the people of Springfield into slaves, Bart and Milhouse at the mercy of Lisa's multiple personalities, and The Simpsons vacationing at a ''Jurassic Park''-esque wildlife refuge.

'''Homer:''' ''(terrified)'' [[WesternAnimation/SpongeBobSquarePants SpongeBob]]?

** As mentioned above in ShoutOut, Homer initially believes that [[SpongebobSquarepants Spongebob]] is the ‘’evil god’’ that the Sea Captain is referring to.

* BeethovenWasAnAlienSpy: Actually, it was [[UsefulNotes/SteveJobs Steve]] [[NoCelebritiesWereHarmed Mobs]] this time around, being a posthumous plant to ensnare everyone on Earth with their electronic devices.
* CallBack: This is the second episode with an alien invasion orchestrated by impersonators of authority figures, the first being about the 1996 election.

* SeldomSeenSpecies: One of the senior citizens transforms into a (giant) ''Longisquama'', and Agnes's pterosaur form is evidently a ''Ludodactylus'' due to possessing both teeth and a ''Pteranodon''-like crest.

* PlotAllergy: Millhouse can’t chew off his leg to get free, since he’s allergic ''[[UpToEleven to himself]]''.

* JurassicFarce: This segment is an obvious parody of the whole franchise, even throwing a few setpieces from ''Film/JurassicWorld''.

* WholePlotReference: To ''Film/JurassicPark''.

* StockDinosaurs: ''Stegosaurus'', ''Brachiosaurus'', ''Iguanodon'', ''Parasaurolophus'', ''Compsognathus'', ''TyrannosaurusRex'', ''Triceratops'', ''Pachycephalosaurus'', ''Ankylosaurus'', ''Dilophosaurus'', ''Velociraptor'', ''Allosaurus'', ''Apatosaurus'', and ''Mosasaurus'' are among the genera the seniors transform into.

* YourCheatingHeart: At the town cemetery, a man drops off a flower at the grave of his wife and then a bouquet at the grave of his secret wife. The grave for his boat gets an [[UpToEleven even larger]] bouquet!

** Geriatric Park has a banner on the entrance reading "Now Goldblum-Free", a jab at actor Creator/JeffGoldblum (who plays the BreakoutCharacter among the humans, Dr. Ian Malcolm, in the ''Jurassic Park'' franchise). There's a touch of BitingTheHandHumor here, as Goldblum was a guest voice in Season 7's "A Fish Called Selma" (as Troy [=McClure=]'s agent).