In this year's scary installment, a botched Mayan sacrifice in the past brings about TheEndOfTheWorldAsWeKnowIt in the future, Lisa keeps a black hole as a pet in "The Greatest Story Ever Holed," The Simpsons catch paranormal activity on tape in "Unnormal Activity," and Bart goes ''Film/BackToTheFuture'' and ends up being the son of Artie Ziff in "Bart and Homer's Excellent Adventure."

* AnachronismStew: When the Mayans figured out when the world would end, they decided not to worry and that [[UsefulNotes/BarackObama Obama]] would be blamed for it.
* BlackComedyRape: Homer is forced into three-way sex with two demons to save his youngest daughter. Subverted when Homer removes his clothes and suggests an unnamed sexual technique he wants to try, which grosses out the very demons who want to rape him. (May double as TooKinkyToTorture.)
* BrokenPedestal: Poor Lisa falls victim for this trope when at first, she is credited for the creation of the Subatomic Supercollider but when it backfires, she is told off by Mayor Quimby.
* {{Foreshadowing}}: Bart's time travel to 1974 is foreshadowed by a comic book cover titled "Fantastic Foreshadowing".
** Co-executive producer Joel H. Cohen's Halloween name is "Black Hole H. Cohen (spoiler alert!)"
* FutureMeScaresMe: 1974 Homer is quite disturbed by his future self's appearance. (In fact, this scene provides the picture for the trope's page.)
* KidFromTheFuture: Bart walks up to 1974 Homer and introduces himself as "the unwanted son from the future who kills all your fun."
* MesACrowd: To win Marge back, Homer gathers all the Homers from various times in history.
* SafeWord: Homer and the demons agree on "cinnamon". Ironically, it's the ''demons'' who shout it first.
* ShoutOut: The title "Bart and Homer's Excellent Adventure" is based on ''[[Film/BillAndTed Bill & Ted's Excellent Adventure]]'', the title of the comic book that foreshadows Bart's TimeTravel is [[ComicBook/FantasticFour "Fantastic Foreshadowing"]] and Bart's travel to 1974 includes a [[{{Wormhole}} wormhole]] that features titles of ''Film/JamesBond'' films made between then and the episode's present time.
** "Unnormal Activity" spoofs the ''Film/ParanormalActivity'' films.
* TooDumbToLive: Lisa, of all people does this in "Unnormal Activity" because she angrily exclaimed that she thought she was the favourite child in front of the devil who was attempting to take Maggie because she was the favourite child. Lisa does quickly change her mind after the devil gives Maggie back and attempts to take Lisa instead.