In this year's scary installment, a botched Mayan sacrifice in the past brings about The End of the World as We Know It 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 Back to the Future and ends up being the son of Artie Ziff in "Bart and Homer's Excellent Adventure."
- Anachronism Stew: When the Mayans figured out when the world would end, they decided not to worry and that Obama would be blamed for it.
- Black Comedy Rape: 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 Too Kinky to Torture.)
- Broken Pedestal: 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.
- 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!)"
- Future Me Scares Me: 1974 Homer is quite disturbed by his future self's appearance. (In fact, this scene provides the picture for the trope's page.)
- Kid from the Future: Bart walks up to 1974 Homer and introduces himself as "the unwanted son from the future who kills all your fun."
- Me's a Crowd: To win Marge back, Homer gathers all the Homers from various times in history.
- Safe Word: Homer and the demons agree on "cinnamon". Ironically, it's the demons who shout it first.
- The title "Bart and Homer's Excellent Adventure" is based on Bill & Ted's Excellent Adventure, the title of the comic book that foreshadows Bart's Time Travel is "Fantastic Foreshadowing" and Bart's travel to 1974 includes a wormhole that features titles of James Bond films made between then and the episode's present time.
- "Unnormal Activity" spoofs the Paranormal Activity films.
- Take That!: When Homer arrives to confront Artie Ziff and "take [his] life back":Artie: I thought this might happen...so I mastered Brazilian Jiu-Jitsu! [lies on his back] Fall atop me and meet your doom!Explanation
- Too Dumb to Live: 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.