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]

A social worker is assigned to make the Simpson family functional after they get arrested for fighting while playing Monopoly. He helps them learn how to work together and function as a family. The moment is ruined when, Ginger and Amber, the barmaids who married Homer and Flanders while they were drunk in "Viva Ned Flanders", arrive at the Simpsons' home, which outrages Marge.

Homer is humiliated when he appears on the news running from a bear that nearly attacks him at the city dump. After Grampa scolds him, he swears to fight the bear himself.

Krusty discovers that he never had a bar mitzvah as a child. He quits his show to have it as an adult, with the help of his father, Rabbi Krustofski. Meanwhile, Homer hosts a late-night talk show a la "Politically Incorrect with Bill Maher" as a replacement for Krusty's show.

When Bart writes slogans on T-shirts, he catches the attention of Goose Gladwell, a gag-gift entrepreneur, and soon becomes a T-shirt mogul; Homer feels he no longer has a place in the family when Bart becomes the breadwinner.

Flanders rents a room to two college girls who, without his knowledge, use the spare room to broadcast live softcore pornographic web videos of themselves. Upset that no one in town told him this (and that Homer was the one who told everyone), Ned moves to the seemingly perfect town of Humbleton, Pennsylvania, while a brash coach moves into Flanders' house and begins harassing Homer the same way Homer harassed Ned.

Marge is shunned after Homer has an altercation with the Easter Bunny at the mayor's egg hunt. A lonely Marge joins a women's group who plan to steal $1 million from Mr Burns.

Mail from forty years earlier is discovered, and a letter from Homer Simpson's mother's old boyfriend states that he is Homer's true father. Homer sets out to find his supposed new father, leaving Abe behind.

When Homer hears that the Isotopes are on a winning streak, he takes the family to the game. The first baseman’s game is going bad, caused by his sexy singing wife Tabitha embarrassing him during the game’s national anthem. Buck Mitchell sees Marge and Homer’s kiss on the game’s Kiss-Cam and comes to them for marital advice. They start working with the couple and Buck’s baseball career turns around, but it and the Simpson marriage goes awry again when Buck catches Homer giving Tabitha a neck massage. While Marge and Homer try keeping their marriage together they also try to get Buck and Tabitha back together.

Homer learns three lessons about revenge from stories told by Marge, Lisa and Bart that parody "The Count of Monte Cristo," "Revenge of the Nerds" and "Batman Begins."

Homer falls in love with the high life of flying in private planes when he saves Mr. Burns from drowning, and Burns repays him by flying him to Chicago for a night on the town.

A new kid at school named Donny works with Bart on his pranks. But when the pranks start to backfire, Bart wonders if he can trust his new accomplice. Meanwhile, the Simpsons get a fancy loaner car after Marge gets in an accident, and Homer falls in love with it.

Homer's mother, Mona, returns, but Homer is reluctant to trust her because she abandoned him so many times as a child.

After Marge and Homer's marriage turns out to be invalid, they decide to re-do their vows. But when Homer goes missing, Bart and Lisa smell something funny and investigate his disappearance.

The episode consisted of three self-contained segments: In "War and Pieces", Bart and Milhouse discover a real-life board game that they must win to return home; in "Master and Cadaver", Marge and Homer go on a honeymoon on a sailboat, and rescue a mysterious castaway named Roger; and in "Tweenlight", Lisa falls in love with a vampire named Edmund.

Discovering that Marge was once a stellar A+ student whose grades plummeted after being distracted, Lisa fears that she will end up just like her mom unless she pledges to focus solely on academics in an encore episode. When Marge makes a secret deal allowing Lisa to attend her dream school, Lisa learns a lesson in family and altruism. Meanwhile, Bart puts Nelson Muntz in his place and unintentionally claims the title of "School Bully"

When Homer insists Bart must earn the new dirt bike he wants, Bart comes up with a scheme; James Lipton interviews a TV cast.

Homer and Marge try to track down Grampa by following clues that lead to secrets from his past.

The fate of Springfield Elementary rests on Bart and his test scores, and Homer finds way to make money with his own parking meter.

Principal Skinner promises the students that the best-behaved among them can take a ride in a submarine. When Skinner gives all the kids a clean slate, Bart believes even his own past indiscretions will be forgotten if he doesn’t get into any more trouble. Meanwhile Lisa tries to help a cash-poor Krusty to turn things around by suggesting he sell the foreign rights to his shows.

Scotty Boom, a Chew Network super-chef, challenges Homer to a smoke-off. But when someone steals Homer’s secret weapon – a smoker he bought off a mysterious man at a BBQ shack – Lisa and Bart are on the case.

In the annual fright fest Halloween episode, Sideshow Bob finally kills Bart, only to reanimate him; Homer wakes up with short-term memory loss; and Lisa, Bart, and Milhouse get super powers from radiation.

There is a new teacher at Springfield Elementary, and a captivated Bart tries everything to win her over. Meanwhile, Homer decides to buy a new brand of “milk,” which causes early puberty, both for Bart (augmenting his wooing powers) and Lisa (whose small bout with acne opens her up to the world of makeup and popularity).

Better late than never, The Hunger Games come to Springfield!

Bart goes from delinquent with detention to the star basketball player at Springfield Elementary. Lisa covers Bart’s success for the school paper, and Homer becomes the team’s coach. Things go awry when Bart gets involved with the mafia

Homer wins an oyster-eating contest against the mythical Cthulhu, Springfield is overrun by plant body-snatchers, Lisa finally snaps and Mr. Burns opens a retirement home with some Jurassic upgrades.

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.

When Lisa spots a new best friend from the window of the bus, she gets a taste of what life could be like with a different, more cultured family.

After severing her sibling ties with Bart, Lisa attends a sleepover at her new friend Addy's house, only to discover that Addy's clique are a group of cruel snobby rich girls that taunt her. Meanwhile, Homer takes Marge on a sunset cruise for the evening and finds himself at odds with the boat's cover band.

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

Evergreen Terrace is overrun with traffic and Moe has a fateful choice to make.

Cletus discovers that his wife Brandine has been hiding a secret love ... of learning.

Coach Moe recruits the world's greatest brawlers to teach Nelson the art of hockey goonery.

Homer and Bart become kings of the blue-collar sports circuit, but Marge suspects something dishonest at the core of their father-son bond.

Professor Frink secretly helps Homer, through a zoom interview, land a high-level position at a state-of-the-art nuclear plant in Shelbyville. But since Homer lacks the skills to actually perform the job, Frink must monitor Homer's work situation remotely and dictate his every word... causing Frink to fear he's created a monster.