[[quoteright:264:http://static.tvtropes.org/pmwiki/pub/images/treehouse_of_horror_xviii.png]] Kodos is a murderous ''E.T.'', Homer and Marge are dueling husband and wife assassins, and Flanders uses the seven deadly sins to scare some Halloween hoodlums straight.

!! Tropes:
* BondOneLiner: Parodied in "Mr. And Mrs. Simpson" as Homer plans to kill Kent Brockman:
-->'''Homer''' ''(thinking)'': Now to think of a cool thing to say before I kill him.
-->'''Homer''' ''(thinking)'': ''Ooh!'' That's a ''good'' one! But I don't have to say it aloud because no one's with me!
* DealWithTheDevil: Ned channels Satan in order to gain powers to [[DisproportionateRetribution punish the children]].
* DirtyCop: Wiggum investigates Homer and Marge after they fight when they discover that they were both assassins. Marge shoots him with a crossbow to stop him, and his FamousLastWords are "I would have accepted a bribe".
* DownerEnding: One of the few Halloween episodes to avert this. (Although it's ambiguous as to if the deaths in Heck House really happened)
* NoFourthWall/ BitingTheHandHumor: The introductory/ credit segments basically involves Marge murdering every Fox advertisement involving the NFL, ''American Idol'', and FOX's popular dramas and feeding them to the family.
** At the end, Ned tells us that we're going to Hell for watching FOX. "And that includes, FX, FOX Sports, and our newest Devil's portal ''The Wall Street Journal''."
* InsistentTerminology: Since Kodos was alive at the end, it was a vivisection and not a dissection.
* RiddleForTheAges: Whatever Homer thought about saying when he was about to kill Kent Brockman, he never said.
* SevenDeadlySins: "Heck House"
* ShoutOut:
** "E.T. Go Home" is a parody of ''Film/ETTheExtraTerrestrial''.
** "Mr. & Mrs. Simpson" is a parody of ''Film/MrAndMrsSmith2005''.
** In "E.T. Go Home'', the hordes of Kang's troops emerge from the space portal via resurrecting broomsticks of "[[Disney/{{Fantasia}} The Sorcerer's Apprentice]]".
** In "Mr. & Mrs. Simpson" when Mr. Burns tells Homer to kill Kent Brockman, the picture of Kent Brockman is his mugshot which parodies Creator/NickNolte's infamous mugshot.