In a parody of The Omen, Homer and Marge bring Maggie home after trading her due to originally having a boy, and she shows satanic powers and torments the family and the other people of Springfield. Ned vows to get rid of the evil, sacrificing her inside the First Church of Springfield, but Homer and Marge stop him. Ned however shows them the Mark of the Beast on her head, Mickey Mouse's logo, and then reveals 666, 666, parodying that this is the 666th episode. Maggie then kills all three of them, and the title for the episode appears, up top of the number of the beast 666 reads "episode" and below "or 667 if fox changes the schedule"
Danger Things
The plot is a parody of Stranger Things season 1, featuring Milhouse as Will, Bart as Mike, Nelson as Dustin and Lisa as Eleven. The story takes place in the 1980s, where after a night of playing the Atari 2600 game E.T. the Extra Terrestrial, Milhouse gets kidnapped by a Demogorgon. A concerned Kirk starts going crazy by destroying the wall and creating a christmas light alphabet communication thing to look for his son. Milhouse in the Over Under calls the Simpsons house with Lisa picking up, after Milhouse realises Lisa doesn't love him back he hangs up. Lisa goes to Starcourt Mall to find Bart and Nelson at the arcade. She tells them that Milhouse is still alive and in another dimension. They decide to get help from Professor Frink to travel to the Over Under. Lisa finds Milhouse in the other dimension and try to escape till they find an alternate version of Springfield full of Demogorgons. Lisa and Milhouse are surrounded by Demogorgons so Lisa uses her psychic powers to get rid of the creatures. They are finally saved by Homer, who's working for Mr. Burns's secret government program to find monsters. Sadly they are actually trapped in the dimension so The Simpsons decide to live in the Over Under. Homer is glad there isn't any Ned Flanders in the Over Under until a Demogorgon version of Flanders appears, causing Homer to burn the Demogorgon.
Heaven Swipes Right
In a parody of Heaven Can Wait, Homer chokes on a hot dog while watching a football game and ascends to Heaven. However, when it's discovered he shouldn't be dead, he is placed in the body of a handsome, athletic man. Marge is delighted but Homer quickly ruins his new body and has to change again. He takes the body of Superintendent Chalmers and Bart uses him to torment Principal Skinner. However, when he sees the size of his paycheck, he dies of shock. After inhabiting a monkey, Homer ends up taking Moe's body. In a twist, it's revealed that Moe has taken over Maggie's body.
When Hairy Met Slimy
A parody of The Shape of Water, featuring Selma as Elisa and Kang as The Amphibian Man. Selma falls in love with Kang and helps him escape captivity with Homer's help. Pursued, they meet up with Kodos at the top of Mt. Springfield. Selma is shot and Kang destroys the pursuing soldiers with an Infinity Gauntlet. Kang resurrects Selma, telling her he is pregnant. Patty arrives to stop Selma but soon falls for Kodos, when they both confess their sexual preferences to each other. They all honeymoon together with Patty and Selma nagging their husbands. The episode ends with a collage of clips from previous Treehouse of Horror episodes.
Reception
The episode was moderately well-received by critics. AV Club gave it an overall grade of B-, and said "The XXXth/666th "Treehouse Of Horror" is just The Simpsons' wheezy annual horror exercise." Frightday was less impressed, saying "It’s hard to criticize a late series Simpsons episode without sounding like an old man yelling at a cloud, but this installment was a big letdown." “Den of Geek” gave it 4.5 out of 5 stars.
