Homer's silhouette appears next to Alfred Hitchcock's iconic silhouette. He emerges and warns viewers that the following episode could scare certain viewers, especially religious types, an announcement mirroring Marge's intros to Treehouse of Horror and Treehouse of Horror II. He requests for the television to be turned off before daring viewers and imitating a chicken. The TV screen eventually switches off; however, Homer and Marge can still be heard if not seen. The episode then pans to a cemetery and eventually to the Simpsons' house, with the family in their couch gag as skeletons.
The Simpsons are having a Halloween party, and they tell scary stories. The Halloween costumes include Homer wearing a toga as Julius Caesar (the toga is caught on the stairs and is totally ripped off, exposing his white underpants), Marge as an ancient Egyptian (most likely Cleopatra), Bart as Alex DeLarge from A Clockwork Orange, Lisa as the Statue of Liberty, Milhouse as Radioactive Man, Martin as Calliope, Nelson as a pirate, Janey as a princess, Wendell as an astronaut, Lewis as Frankenstein's Monster, Richard as Scratchy and Ned Flanders as a headless zombie.
Clown Without Pity
Marge gathers everyone around a circle for a party game in which everyone passes around various food items (such as peeled grapes and cold pasta) pretending they're the portions of a dead witch's body. Unfortunately, a gluttonous Homer ruins the game for everyone by eating everything. Not sure what to do, Marge asks if anyone has a scary story to tell and Lisa says that she has the story of boy and a doll from Hell. In a parody of the Twilight Zone episode "Living Doll", as well as the Child’s Play franchise, Bart is celebrating his birthday and has obtained multiple good presents and Grandpa's social security money. Unfortunately, Homer forgets to get a present and rushes out to buy a gift for his birthday. Homer buys Bart a talking Krusty doll at 'House of Evil' (your one-stop Evil gift shop) which also sells frozen yogurt called "frogurt". Upon receiving the Krusty doll, Bart excitedly says "Great Caesar's ghost!", a catchphrase said by Perry White of the Superman comic book series. Although the doll is nice to Bart, it repeatedly tries to kill Homer (which no one believes). Homer captures the evil Krusty in a bag of dirty socks, which he then locks in a suitcase. He disposes of the suitcase in a "Bottomless Pit" and returns home, not realizing that the doll has managed to follow him. As the doll attempts to strangle Homer, Marge calls KrustyCo for help; a repairman arrives and discovers that the doll has been accidentally switched from "Good" to "Evil." He flips the switch back to "Good" and Homer uses the doll as a servant. The Krusty doll laments to his "girlfriend" Malibu Stacy, with whom he shares Lisa's dollhouse, "Today Homer made me give him a sponge bath!" However, the scene finishes happily as Krusty gives Stacy a smooch on the cheek—until her head falls off.
The scene cuts back to the living room, where Homer is trying to tell his own story, which turns out to be absolutely prosaic. Grampa comes into the room and dismisses Homer's story, saying that he's coughed up scarier things. Bart suggests that Grampa tells a story since he has, "lived and interesting life". Grampa dismisses Bart's claim, but remarks that he has seen a lot of movies and the scene transitions into a black and white segment parodying King Kong, Marge joins Mr. Burns and Smithers on an expedition to "Ape Island" to find the legendary "King Homer". Upon arriving at the island, Burns betrays Marge and uses her as bait to attract the giant ape. When King Homer does arrive, he kills off a good portion of Mr. Burns' crew. Burns' attempts to sedate the him with a gas bomb but only succeeds in gassing himself by mistake, so Smithers tosses the grenade himself, finally sedating the King Homer. With the ape in his custody, Mr. Burns returns to America and presents King Homer to the press on Broadway. The photographers' camera flashes enrage King Homer, who breaks free from his restraints. He abducts Marge and wreaks havoc, eating many people in the process, including Shirley Temple performing "On The Good Ship Lollipop" on Broadway. He attempts to climb the Empire State Building but is unable to get even one story above the ground. King Homer collapses in exhaustion, and Marge helpfully suggests that he eat more vegetables and fewer people. In the end, King Homer and Marge marry on the same day Dick Cavett is born (November 19, 1936). The story finishes with the wedding, and King Homer eating Marge's father Clancy Bouvier, although Marge is brave and not upset.
Dial "Z" for Zombies
Marge enters the living room with a bowl of fresh fruit in place of candy, much to the disappointment of the guests, when a screaming headless man enters the house and everybody starts screaming. However, it turns out just to be Ned Flanders wearing a headless zombie costume. Bart commends Ned for his prank, but then remarks that he has story so scary that people will wet their pants (only for grandpa to tell him that he's too late, to everyone's disgust). The story begins in class, where Bart presents his book report to the other students. His book of choice? An A to Z alphabet book for preschoolers. Ms. Krabappel informs him that the book is unacceptable as one for the report and he'll have to start again from scratch. While in the school's library searching for material for a book report (gratifyingly considering to choose a, "Where's Waldo" book as his option), Bart notices the occult section and explores it out of curiosity. While in the section, he finds a book of magic and decides to use the book for his report. Upon returning home, Bart tries to impress Lisa with the book, but she's uninterested as it's the four year anniversary of Snowball I's death. In order to make Lisa happy, Bart takes her to the pet elementary and tries to resurrect Snowball for her but ends up casting the wrong spell and accidentally reanimates hundreds of human corpses instead. The zombies terrorize Springfield, turning several people, including Principal Skinner, Ned Flanders, Krusty the Clown, Sideshow Mel, Edna Krabappel, and the bullies, into zombies. Meanwhile, the Simpson family has barricaded all the doors and windows except for the front door, which Homer completely forgot to do because he was watching TV. Several zombies break into the house. Homer tries to sacrifice 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 family runs to the car under the protection of Homer’s shotgun. Flanders comes over and asks, "Mind if I chew your ear?" Homer responds by blasting Flanders with his shotgun. The family voice their surprise that he killed the zombie Flanders, to which Homer responds, “He was a zombie?" Meanwhile, Kang and Kodos observe the anarchy unfold from their ship hovering in orbit and remark that soon the human race will fall to the zombies while they laughing maniacally. Shortly thereafter, the Simpsons arrive at Springfield Elementary and burst through the doors until Homer wields a shotgun to kill the famous zombies including George Washington, Albert Einstein, and William Shakespeare. While their parents distract the horde, Bart and Lisa successfully make it to the occult section of the Springfield Elementary library. Bart finds another book of magic and casts the spell—that accidentally turns Lisa into a snail, resulting in him letting out a quick gasp. Lisa doesn't notice her transformation and asks Bart what the problem is. To keep her from getting annoyed, he replies, "I never realized what a beautiful, young woman you've become," flattering her. Bart finds the correct spell and casts it upon the world, returning the zombies who were dead before the spell to their graves, making those who became zombies by infection drop dead in the streets and turning Lisa, who had been unaware of her change, back to normal. In the end, the family is back at home on the couch watching TV. Although Marge is glad they never became zombies, the family starts behaving like it, starting with Bart and Homer just before the credits roll.