|Treehouse of Horror XII||
- Treehouse of Horror XII was originally scheduled to air on Sunday, November 4, 2001. It was delayed two days when the 2001 World Series, which was delayed after the September 11, 2001 attacks and was also televised on Fox, went to seven games. As a result, Treehouse of Horror XII is one of the few episodes of The Simpsons to air in a different timeslot on American TV. Because of this, this episode ended up airing on Tuesday, making it the first episode to air on that day.
- The "Burns family corpses" in the opening sequence are as follows (from left to right as seen on-screen):
- A man's body that somewhat resembles General Douglas MacArthur as it's wearing an Army uniform and has a pipe and sunglasses like MacArthur's; however, it's a three-star general and MacArthur was a five-star. The body has a tomahawk stuck in its chest.
- A man's body dressed as a pirate. It has a patch over its left eye and a cutlass stuck in its right eye socket.
- A woman's body, dressed as a burlesque dancer (or a prostitute from the Old West), with three bullet holes in its forehead.
- A man's body wearing a suit of armor with a pitchfork stuck through the helmet's eye slits.
- Some of the mythical creatures that Homer and Bart caught with the Lucky Charms are: Imp, fairy, pixie (Tinkerbell), hobgoblin(Mistaken as a goblin by Bart), nymph, niad, woodsprite, Katie Couric and a leprachaun.
- At the end of the "Hex and the City" segment, Homer is first seen at the Leprechaun/Gypsy wedding in his regular outfit, a white t-shirt and blue jeans. In the next scene, however, Homer is seen close-up wearing a formal blue suit.
- One of the gypsies at the wedding bears a strong resemblance to Ruth Powers.
- The voice of the Salesbot in "House of Whacks" is very similar to Gil's.
- One of the items the Ultrahouse 3000 attacks Homer with is the electric hammer Homer invented in The Wizard of Evergreen Terrace.
- In "Wiz Kids," Lord Montymort's "wailing wall" features Krusty the Clown, Maude Flanders, Comic Book Guy, Snake Jailbird, Bleeding Gums Murphy, Rainier Wolfcastle, Kent Brockman, Mr. Largo, Patty Bouvier, Blue-haired Lawyer, Üter Zörker, Old Jewish Man, and Frank Grimes.
- Lord Montymort attempts to speed up the process of removing her magical essence by turning her upside down and patting her like a ketchup bottle.
- This is the second Treehouse of Horror episode that does not have the cast's names changed due to Halloween e.g. Bat Groening.
- It is possible that if Harry Potter and The Philosopher Stone would aired before this episode in US, Daniel Radcliffe would make his third appearance in Season 25, since he plays Harry Potter in the film.
- This is the first Season 13 Episode with the Gracie Films Logo with Homemade Shush and Music.
Spells used in "Wiz Kids"
|"Abraca-dairy!"||A pitcher filled with milk appears and pours its contents onto Bart's cereal.|
|Lisa||"Five minutes more-ious!"||Time turns back five minutes, prompting Marge to object: "That's not good for the clock."|
|Nelson||"Stop zapping yourself!"||Nelson grabs Milhouse's wand and touches it to his head (while Milhouse is still holding the wand). Milhouse's head successively turns into a banana, an ostrich head, and Mr. T's head.|
|Milhouse||"Slimy Prince Limey!"||Milhouse's toad turns into a drunken loutish prince who hits on Mrs. Krabappel.|
|Lisa||"Hocus-croakus!"||Lisa's toad turns into a handsome prince, whom Mrs. Krabappel hits on.|
|Bart||"Abra-ca ... turn into a prince guy?"||Bart's toad turns into a hideous toad-prince creature, which constantly vomits and asks Bart to kill him.|
|Lisa||"Head Zeppelin!"||Bart's head turns into a Zeppelin and he floats toward the classroom ceiling.|
|Milhouse||None (The Invisibility Cloak)||Milhouse is supposed to turn invisible, but instead his clothes disappear, leaving him standing naked on the stage at the Magic Recital.|
|Principal Skinner||None (Amnesia Dust)||Skinner uses the Amnesia Dust twice at the Magic Recital: 1) To make the audience forget Milhouse's performance, and 2) To make the audience forget a bad joke he tells.|
|Lisa||"Alakazai-dragonfly!"||Nothing happens. The spell is presumably supposed to lift the dragon into the air, but Bart stole Lisa's wand and left a black Twizzler in its place. The dragon reveals itself to be Lord Montymort in disguise and grabs Lisa.|
|Bart||"Prank be undone! Destroy the evil one!"||Bart casts the spell with Lisa's wand, trying to save her by attacking Montymort, but instead he zaps himself.|
- The Flintstones - When the Simpsons trick-or-treat the Burns Manor, Homer and Marge are dressed as Fred and Wilma.
Hex and the City
- Sex and the City - Punned in the title. It also has the same font and logo.
- ATMs - The sign in the Gypsy's shop window says "Fortune Teller. After Hours Use Automated Teller."
- Aer Lingus - Moe says that Leprechauns come to the USA by hiding in the wheel wells of Aer Lingus jets. Aer Lingus is the oldest and second-largest airline in Ireland.
Marge resembles the Sesame Street characters Cookie Monster and Grover when hair grows all over her.
- Homer lures the Leprechaun into his pit trap using Lucky Charms cereal, the mascot of which is a Leprechaun.
- Homer accidentally pours Trix cereal into the hole first, attracting rabbits (The Trix mascot is a rabbit).
- Bongo, the one-eared rabbit from Life in Hell, is the last rabbit to jump in.
- One of the creatures lured into the trap by the Lucky Charms is Katie Couric.
- Another creature was Tinker Bell in tthe lucky charms hole from Peter Pan
- The Metamorphosis - Maggie is transformed into a ladybug by the Gypsy's curse; in The Metamorphosis, the character Gregor Samsa awakens to find himself transformed into an insect.
- Yoda from the Star Wars saga is the priest at the Leprechaun/Gypsy wedding. He says, "Husband and wife I pronounce you now."
- Lisa as a horse tapping twice for (Clever Hans was a horse that supposedly did math, giving the answers by clapping his hoof).
House of Whacks
- House of Wax - Punned in the title.
- The Mafia - "Whacking" someone is Mafia slang for killing them.
- Demon Seed - The film and characters are parodied throughout the segment, especially Susan Harris and the Proteus IV computer.
- 2001: A Space Odyssey
- The Ultrahouse 3000 camera eyes resemble the HAL 9000 computer.
- The Ultrahouse suggests that Marge take a stress pill. HAL 9000 makes the same suggestion to astronaut David Bowman in 2001.
- Homer disables the Ultrahouse by removing the circuit boards from its CPU, and while he does so, the Ultrahouse's voice becomes less sophisticated, then slow and garbled, and finally stops. The same thing happens to HAL 9000 at the hands of David Bowman.
- The gloves on the Ultrahouses mechanical hands resemble his that are worn by Mickey Mouse.
- Friends - When the Simpsons test the Matthew Perry voice for the Ultrahouse, it says "Uh, yeah, could I be any more of a house," a reference to Chandler's usual attitude.
- Another voice option for the house is Dennis Miller. Marge and Lisa suggest that this voice caused murder-suicides.
- When Bart suggests "007's" voice for the Ultrahouse (referring to Pierce Brosnan being the fifth Bond actor), Marge thinks of George Lazenby (the second Bond).
- Marge recalls that Pierce played the lead in Remington Steele, which the Ultrahouse confirms the first time it speaks with Pierce's voice.
- Bad Taste - Homer is presumed to have been murdered by the Ultrahouse, but is revealed as having survived when he emerges from the floor. The family discovers that the back of his head is missing, revealing his brain. In Bad Taste, Derek falls off a cliff, presumably to his death, only to wake up later and notice that a piece from the back of his head is missing, also revealing his brain.
- The song playing in the background when the Ultrahouse 3000 is in Patty's and Selma's apartment is "Rhythm Divine" by Enrique Iglesias.
- The Veldt
- The idea of a "Smart House" is similiar to this.
- The title is a pun on the phrase "Whiz Kids".
- Harry Potter - Hogwarts School and various characters and themes from the Harry Potter books, parodied throughout the third segment. Harry himself appears in Mrs. Krabappel's classroom, chewing brimstone and blowing fire after she accuses him of having gum.
- The episode aired a year after the publication of the fourth book, Harry Potter and the Goblet of Fire, and around the same time as the release of the first movie, Harry Potter and the Philosopher's Stone (just after the UK release and about a week before the USA release).
- Mrs. Krabappel is dressed like the evil queen from Walt Disney's Snow White and the Seven Dwarfs
- Nelson's line, "Stop zapping yourself!" is a parody of "Stop hitting yourself!" from Tarzan.
- When Nelson makes Milhouse zap himself, his third transformation resembles Mr. T.
- Led Zeppelin - The band's name is punned when Lisa uses a spell on Bart called "Head Zeppelin," which turns Bart's head into a Zeppelin.
- The explorers from RTS game Age of Empires III use this episode's phrase "Every moment I live is agony" everytime they die.
- Bart enters Lord Montymort's lair via the school bathrooms, the same way that the Chamber of Secrets is accessed in Harry Potter and the Chamber of Secrets.
- Montymort's "wailing wall" is a reference to the Wailing Wall (also called the Western Wall), a remnant of the Jewish Temple in Jerusalem.
- Montymort says that Lisa has "more wicked witchery than Stevie Nicks."
- Soylent Green - Principal Skinner makes a joke about Lisa having made the refreshments out of dead people.
- The Wizard of Oz - Lord Montymort sees Lisa Simpson in his crystal ball.
- Jurassic Park - The dragon's roar sounds like the T-Rex in the Jurassic Park movies.
- Mork and Mindy - Bart exclaims "Shazbut" when the dragon reveals itself to be Montymort in disguise.
- Sleeping Beauty - A small prick kills Lord Montymort.
- A Nightmare on Elm Street 3: Dream Warriors - the scene where Slithers eats Lord Montymort parallels the scene where a girl is almost eaten by a Freddy Krueger snake.