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.

After receiving an injection from Dr. Hibbert, Bart becomes temporarily deaf, which makes him impervious to being bullied, until he accidentally moons the American flag during a donkey basketball game, prompting everyone in town to accuse the Simpsons of being unpatriotic under the new "Government Knows Best" Act.

After the family successfully protest against a stamp museum being built next to their house, a cemetery is built near the Simpson house instead, making the normally unflappable Lisa realize that someone as smart as her can be afraid of something.

Homer brings the whole family along when he is sent to Italy to pick up a new sports car for Mr. Burns, when they find themselves in a small town that Sideshow Bob has become the mayor of.

The Simpsons' pooch, Santa's Little Helper, becomes a police dog.

Lisa receives Springfield's Entertainer of the Year Award, and Sideshow Mel narrates her history in showbiz in a wry spoof of "All About Eve."

Bart lands himself in trouble when he steals a mobile phone from Denis Leary and subsequently uses it to land the actor a comical film role. The troublemaker then leads his family to the ancient ruins of Machu Picchu after Marge confiscates the device and decides to use its GPS technology to track her son.

Moe once again searches for love and falls for a woman named Maya over the Internet. However, when Moe meets Maya face-to-face, he discovers it's more like face-to-knee, as Maya is only three feet tall.

Principal Skinner announces that Mrs. Krabappel was called out of town and budget cuts dictate that, until she returns, the school's two fourth grade classes will merge. Bart reluctantly shares a desk with Nikki and develops a flirtatious rapport. Bart talks to Grampa about his new crush, and at Grampa's suggestion, gives Nikki a kiss. But when Nikki starts sending Bart mixed signals, he swears off women forever. Meanwhile, Lisa's classmates ostracize her for being an overachiever, and First Lady Michelle Obama, a self-professed nerd, comes to Lisa's defence.

Bart becomes convinced that his new neighbor, Walt, is his archenemy, Sideshow Bob, disguised and back for revenge. But when Marge tries to convince Bart otherwise by taking him to visit the state penitentiary, a disturbing truth is revealed.

Bart and Homer make a film based on Bart's comic book character Angry Dad. The cartoon becomes a critical favorite and begins to win a number of awards, but Bart becomes upset when Homer takes all of the credit during acceptance speeches.

When the Simpsons discover a collection of keys to every door in Springfield, Lisa stumbles upon an eerie hidden classroom beneath Springfield Elementary School. When she shares her discovery with Principal Skinner, the secret room mysteriously disappears and he takes the only key away. A determined Lisa uses her detective skills to lead her back to the room to solve an old school mystery.

Homer lands his own political talk show and becomes the spokesperson for the Gravy Movement. He then is asked to select the next Republican nominee for President and officially endorses right-wing rock star Ted Nugent.

When Flanders' parents prove to prefer Homer's company to his, he jealously responds by giving Homer a shiner, and then tries desperately to reconcile with him. Meanwhile, Lisa is at a loss to understand why a new substitute teacher is bullying her for no obvious reason.

When Bart's voodoo doll spell accidentally makes his teacher pregnant, he becomes a savior to couples hoping to conceive.

When Duffman (guest voice Stacy Keach) undergoes hip replacement surgery and retires, the company sets up a reality show competition to find his replacement. Homer wins the competition, and because the job requires him to stay sober, he learns that beer isn't as necessary as he thought to have a good time.

Bart lies about being involved in a bulldozer crash, so Marge decides to follow him everywhere until he confesses. Meanwhile, Homer ignores Santa’s Little Helper when Flanders gets a new dog.

Lonely Professor Frink uses science to turn himself into a man whom women find attractive. Then, overwhelmed by the attention, he invents an algorithm to perfectly pair the lonely men and women of Springfield, realizing that scientific exploration is his true love. Meanwhile, Marge, Bart, and Lisa visit Grampa for Valentine's Day and try to rescue the old folks from a drug-induced hallucination that allows them to relive their happiest memories.

After butchering a speech in front of all of his friends at work, Homer turns to improv comedy to gain back his confidence in his public speaking skills. Meanwhile, Marge decides to rebuild Bart’s lackluster treehouse, but tensions rise when Bart questions her building skills. Also, in the episode’s last three minutes, Homer appears LIVE for the first time on television (both for East and West Coast broadcasts) to answer fan questions.

Maggie becomes possessed by an ancient demon, Lisa discovers a creepy/perfect version of her family in an alternate universe and Homer cannibalizes himself.

When Bart goes missing, the town puts together a search party to find him. After most give up hope, Sideshow Bob manipulates Millhouse into revealing where Bart is hiding.

After a failed Black Friday shopping spree, Marge is determined to fix Christmas; Homer and the kids surprise Marge with a vacation to a Florida resort.

Homer must supervise interns, among whom is a go-getter who asks Homer to be his mentor.

Sideshow Bob gets contracted as this year’s mall Santa. Meanwhile, someone is stealing all the Christmas packages off people’s front porches.

Homer is tempted by a British femme fatale while Marge and the kids are on a seaside vacation.

The 32nd annual Simpsons Halloween special includes a spoof of "Parasite" and a segment where Bambi gets his revenge.

When Homer and Marge are lost in an icy wilderness, they must push themselves to their limits to survive.

When Bart's latest prank leads to chaos at Springfield Elementary, Marge and Homer dream of a world in which their rambunctious son was never a Simpson.

When someone in Homer's life passes away, he and guys from Moe's go on a road trip to scatter the ashes... but will their friendship die as well?