"Treehouse of Horror XXIV" is a Halloween-themed episode from the twenty-fifth season of the long running American animated comedy series The Simpsons. It first aired in the United States on the Fox Network on October 6, 2013. The opening title sequence was directed by Mexican-born film director Guillermo del Toro.
In common with all other episodes in the Treehouse of Horror series, it is made up of three different self-contained stories. The first story, "Oh, the Places You'll D'oh!", is a parody of the 1957 children's book The Cat in the Hat, other children's books by Dr. Seuss and the films and TV specials which were based on them. The central idea for the second story, "Dead and Shoulders", comes from the 1972 horror movie The Thing with Two Heads. The final story, "Freaks No Geeks" is a spoof of Tod Browning's 1932 horror film Freaks.
The opening title sequence, directed by the Mexican director Guillermo del Toro, is an altered and extended variation on the series' usual one. The sequence is full of references to horror, science fiction and fantasy literature, television programs and movies, including several films which were directed by Guillermo del Toro himself. Count Dracula, Frankenstein's monster, the Invisible Man, the Mummy and the Phantom of the Opera all make appearances.
"Oh, the Places You'll D'oh!"
The segment takes place on Halloween night in an alternate version of the Simpsons' universe which strongly resembles the world of Dr. Seuss' children's books and the animated cartoons which were based on them.
The children Bart, Lisa and Maggie Simpson are unable to go out trick-or-treating because thay have the mumps. They stay at home while their mother Marge, wearing a Catwoman costume goes out herself. Soon after Marge leaves. A creature which resembles a cross between a cat and the children's father, Homer Simpson, arrives. The creature introduces himself as the Fat in the Hat. He gives the children injections which instantly cure their mumps and promises to take them out to get candy.
The Fat in the Hat does obtain a large amount of candy for the children but he also goes on a rampage of death and destruction, killing everyone who irritates him. The frightened children manage to escape from the Fat in the Hat but find that he is in their house waiting for them when they get home. He tells the children that they will never be rid of him and he will be their new father but the baby Maggie kills him by stabbing him with his own umbrella.
Marge Simpson returns home and has no idea about what has just happened. The children pretend to still have the mumps by stuffing their cheeks with candy.
"Dead and Shoulders"
After a helicopter flies into the string of his box kite, the boy Bart Simpson gets his head sliced off by the kite's string. In spite of having become separated from his body, Bart Simpson's head remains alive and is sown onto the body of his younger sister Lisa.
Lisa usually mainatins complete control over the body but Bart finds out that he controls it while Lisa is asleep. Bart laces Lisa's yogurt with sleeping pills and tries to remove her head, so that he can have the body to himself. Lisa wakes up to find herself tied to a log in a sawmill. She manages to save herself by getting the saw to cut off Bart's head instead of hers but a second saw cuts off her head too.
Bart wakes up in hospital to find that his head has been sown on the body of his Aunt Selma. Lisa's head has been attached to the body of the recurring character Krusty the Klown and the two doctors who regularly appear in the series, the competent Dr. Hibbert and the incompetent Dr. Nick Riviera, are also sharing a single body.
"Freaks No Geeks"
The segment takes place in the 1930s in a circus which is home to Homer the strongman, Marge the trapeze artiste and several freaks, including the aliens Kang and Kodos. Marge cannot stand to see the freaks mistreated because, having one blue eye and one brown eye, she considers herself to be a freak too. Apparently, the most horrifying of all the freaks is the recurring character Moe Sizlak, even though he looks no different to how he appears in every other episode.
Although Homer is in love with Marge, he persuades her to marry Moe instead. The reason for that being that Moe has an emerald ring in his possession. Homer plans to kill Moe, marry Marge, take possession of the ring and use the money he would get from selling it to "get out of this lousy circus and get into a good circus". On her wedding night, Marge discovers Homer attempting to poison Moe's wine. He tells her his plans and she is horrified, telling him that it is he and not the freaks who is the true monster.
After he is forced to leave Marge's caravan, Homer is attacked by the freaks who determine to make him one of them. His limbs are cut off and he is tarred and featherd.
In the present, the children Bart, Lisa and Maggie, who all share a single body, are listening to the story being told by their father, Homer "the Human Duck". Homer says, "And that's how I met your mother". The episode ends with the theme tune to the TV series How I Met Your Mother being played while newspaper clippings which show Homer's successful career as "The World's Strongest Duck" are shown.