The Simpsons are having a Halloween party for the children of Springfield. Lisa, Grampa and Bart each tell a horror story.
In a parody of the Twilight Zone episode, Living Doll, Homer realizes that he forgot to buy Bart a present for his birthday. He rushes to the House of Evil, where he purchases a talking Krusty the Clown doll. The shopkeeper warns him that the doll is cursed, but Homer dismisses his concerns. He returns to the party and gives Bart the doll. Grandpa exclaims that the doll is evil, but admits that he is just doing it to get attention.
Later, Homer is playing with the doll when it starts saying that it is going to kill him. He dismisses this until the doll threatens to stab him. After numerous attempts on Homer’s life, he captures the evil Krusty doll, locks it in a suitcase, and drops it in a "Bottomless Pit". Returning home, Homer is ambushed by the escaped doll, who tackles him into the kitchen and tries to drown him in Santa's Little Helper's dog bowl. Marge calls the consumer service hotline. A repairman arrives and discovers that the doll has been set to "Evil" mode. He flips the switch to "Good" and the Krusty doll becomes friends with Homer.
A few hours later, the Krusty doll is working as Homer's slave. The Krusty doll returns to his girlfriend (a Malibu Stacy doll) in Lisa's dollhouse.
In a parody of King Kong, Marge joins Mr. Burns and Smithers on an expedition to Ape Island to find the legendary King Homer. After landing on the island, Mr. Burns, Smithers, and Marge stealthily approach a native tribe, but are spotted due to Marge’s hair protruding over the bushes. The villagers agree that "The blue haired woman would make a good sacrifice" and tie her to a post as an offering. The sound of drums summons King Homer. Marge is initially terrified but sees the friendly side of Homer when he is attracted to Marge's perfume and the two form a friendship. Nonetheless, Mr. Burns is determined to capture King Homer and Smithers knocks Homer unconscious with a gas bomb. Returning to New York, the group display King Homer at the Broadway theatre. The photographers' flashes enrage King Homer, who breaks free from his restraints. He abducts Marge then attempts to climb the Empire State Building, but is unable to get past the second story of the building. King Homer collapses in exhaustion. In the end, King Homer and Marge get married. The story ends with the wedding.
While in the Springfield Elementary library, Bart finds a book of black magic and gets attached to it. That night, when Lisa reminisces about the family’s dead cat, Snowball I, Bart suggests that he could use the book he found to resurrect Snowball. At the Springfield pet cemetery with Lisa, Bart utters an incantation from the book but accidentally reanimates corpses from the nearby human cemetery instead. The zombies terrorize Springfield, turning many people into zombies. Meanwhile, the Simpson family has barricaded all the doors and windows except for the back door, which Homer forgot to do. Several zombies break into the house: Homer sacrifices himself to give the others time to escape, but the zombies leave him when they realize he does not have enough brains for them to eat. Lisa realizes that the school library must have a book that can reverse the spell.
The Simpsons arrive at the Springfield Elementary library and Bart casts the appropriate counter spell, causing all zombies to return to their graves.