This year's Halloween story sees The Simpsons as "The Munsters" (with everyone except Lisa getting killed), Homer as a wandering spirit on the hunt for a good deed in "G-G-Ghost D-D-Dad," Bart and Lisa as peasants in a fairy tale forest in "Scary Tales Can Come True," and Lisa inadvertently dooming mankind by rescuing a dolphin in "Night of the Dolphin."

Krusty takes parenting lessons from Homer when, during an outdoor book fair, a girl tells Krusty that she is his long-lost daughter from a one-night stand with a female soldier who fought during the first Gulf War.

When Lisa becomes the target of a female bully, Lisa discovers a scientific reason as to why bullies pick on nerds. Meanwhile, Homer goes into the baby-proofing business, which is threatening the businesses of pediatricians and greeting card salesmen.

When Homer refuses to pay a five dollar airport tax to fly to Delaware, the family is forced to ride in a livestock car of a train instead. There they meet a singing hobo who tells three tall tales: Homer as Paul Bunyan. Lisa as Connie Appleseed, a parody of Johnny Appleseed. Bart as Tom Sawyer with Nelson as Huckleberry Finn.

In the twelfth Treehouse of Horror episode:

Hex and the City – While on a day trip through Ethnictown, Homer's bumbling catches the ire of a gypsy, who curses Homer's family and friends into receiving nothing but bad luck.

House of Whacks – in this mixed parody of Demon Seed and 2001: A Space Odyssey, Marge buys an automated house and customizes it with the Pierce Brosnan personality, who falls for Marge and attempts to murder Homer.

Wiz Kids – In this Harry Potter parody, Bart and Lisa go to a school for wizards, and Lord Montemort (Mr. Burns) uses Bart to capture Lisa's magic.

Guest star: Pierce Brosnan and Matthew Perry.[20]

Bart befriends Rainer Wolfcastle's daughter Greta. She has a crush on Bart, but he does not seem to realize it and eventually stops seeing her. Seeking revenge, Greta begins dating Bart's best friend Milhouse, which causes Bart to start missing her. She leaves for Toronto with her father, and Bart convinces his family to follow them there.

The Simpson family win a free spa weekend, and Homer is nearly killed when a mysterious figure locks him in a sauna. Chief Wiggum decides to hire someone who can think like a murderer in order to find one. Bart's mortal enemy Sideshow Bob is sent to live with the Simpsons so he can help find Homer's attempted killer. Bob and Homer track down the attempted murderer and discover that it is Frank Grimes, Jr., the son of a man that Homer drove to insanity (in the season eight episode "Homer's Enemy"). After Grimes is arrested, Bob tries to kill Bart, but he finds that he has "grown accustomed to [his] face" and cannot harm him.

The Simpson family's dog Santa's Little Helper fails to save Homer from a treehouse when it is on fire. Consequently, Homer declares him a coward and disowns him. One day, a photographer finds Santa's Little Helper playing with a Duff Beer can and takes a picture. The picture becomes popular and SLH becomes the new mascot for Duff Beer while the old mascot, Duffman, is fired. Homer earns a lot of money but SLH's original owner shows up, claiming that the dog is rightfully his. Bart fears that he will never see Santa's Little Helper again. The Simpsons conceive a plan to get Duffman rehired as Duff's mascot by showing what a coward Santa's Little Helper is. At a Duff-sponsored beach event, Homer pretends to be drowning (while floating on a keg of beer) but is attacked by a shark. The shark bites the beer keg and becomes drunk, and wins over the crowd on the beach. The shark is named the new mascot of Duff Beer and Santa's Little Helper returns to the Simpson family.

Bart gets sent to juvenile hall after fooling everyone that there was a marriage concerning him. He encounters a dangerous girl there... He flees with Gina, but then the two are caught by Wiggum.

Mr. Burns buys out Springfield's media outlets after a newspaper mistakenly reports his death, and Lisa's homemade newspaper is next on his list.

Homer sees a movie about the end of the world and fears the same thing will happen in real life after seeing a chain of random occurrences (celebrities ["stars"] falling from the sky, raining blood, a man in a realistic devil costume) and doing a complicated math equation that predicts the end will come on May 18th, but when the end does not come, Homer discovers a flaw in the equation and ends up in Heaven where he meets God and learns that God is planning The Rapture.

The Simpsons re-enact the Nativity; a World War II tale stars Grampa, Mr. Burns and Santa; a musical features "The Nutcracker Suite."

Lisa pretends to be Native American for multicultural day at school. Meanwhile, Bart finds love with an older woman.

Homer and Marge celebrate Valentine's Day by going on the Tunnel of Love ride at a carnival, but they end up stranded when Bart pulls a prank involving gelatin. To pass the time, Homer tells the love story of Bonnie and Clyde, Marge tells her version of "Lady and the Tramp," and Bart tells the love story of Sid Vicious and Nancy Spungen.

Homer is jealous when old classmate Vance Connor is inducted into the Springfield Walk of Fame. Lenny and Carl confess they fixed the result in favor of Principal Dondelinger - leading the hapless father to speculate on how his life would have changed had he won the ballot.

Grampa is sitting on a bench waiting for his family when a thoughtful-looking man named Marshall Goldman approaches him and asks to hear about his life. Grampa tells Goldman about the time he was on a World War II battleship, which was hit by an enemy torpedo, and Goldman, a human-interest columnist, publishes it in The Springfield Shopper. Later, Grampa meets Mitch Albom and shares another story with Goldman for a follow-up article. Homer becomes jealous of Grampa's newfound fame and seeks a surrogate father. But when Homer discovers a draft of Goldman's third story, he must race to find Grampa before it is published and his life is changed forever.

When Homer helps a woman give birth in an elevator, he forms an emotional attachment to the baby; cheerleaders for the local professional football team recruit Lisa.

Springfield is inundated with holiday revelers after the nuclear power plant springs a radiation leak, causing snow to fall all over town. When the tourists drive up Christmas shopping prices, Marge opens up the Simpsons' house to boarders.