"Treehouse of Horror XVII" is the seventeenth Treehouse of Horror episode and the fourth episode of Season 18.
In "Married to the Blob", Homer eats green extraterrestrial goo and morphs into a rampaging blob with an insatiable appetite; in "You Gotta Know When to Golem", Bart uses a golem; and in "The Day the Earth Looked Stupid," the residents of early-1930s Springfield refuse to believe news of an actual alien invasion after being duped by Orson Welles's "War of the Worlds" broadcast.
A crypt opens in a dungeon room, and the Crypt Keeper (portrayed by Mr. Burns) sits up in it, proclaiming himself to be the master of scare-amonies, much to the delight of the zombie Smithers. A bound Moe interrupts in protest, but is killed in an iron maiden, his blood spilling out onto the floor and revealing the title of the episode, which he takes delight in having "fancy Roman numerals and everything".
Married to the Blob
Homer and Marge snuggle on the hammock, where a meteorite falls nearby, burning off the top of Marge's hair in the process. Cracking open, it reveals a green goo resembling a melted marshmallow. Despite his family's objections, Homer puts it on a stick and eats it (although the goo tries many times to get away and is clearly alive). That night, after saying "Must eat, then poop, then eat some more, then eat while pooping", his stomach growling from hunger, Homer eats all the food in the house. While transforming into a tall gelatinous creature, Homer also eats the cat and attempts to eat Bart, but is prevented by Marge.
After that, he finds teenagers having a party by a bonfire, which he sees Jeremy Freedman fall into. As Jeremy exclaims that the flames are sealing in his juices, Homer prepares eats him, declaring "I'll savor you!" before he does so. Jeremy's friends run away in fear, and he tells Homer to tell his friends he died kissing a girl, but Homer declines that and finally eats him whole.
At Oktoberfest, Homer eats four fat Germans, voicing his desire to eat more fat people. In a music segment parodying "Baby Got Back", he is shown now as a fat creature walking around, looking for food. He slowly turns from yellow to green, gets taller and fatter, and loses his legs, becoming a tall, fat, green blob that rampages through the streets of Springfield, eating all the fat people he can find.
As Homer samples bus passengers like candies, Dr. Phil McGraw shows up with the Simpson family and tells Homer to stop for their sakes. But Homer doesn't listen to him and eats Dr. Phil. Homer then ends his rampaging for fear of losing Marge, and vows to use his insatiable appetite for more constructive purposes. Later, Mayor Quimby dedicates a new homeless shelter, only for the homeless people who enter to find themselves in Homer's belly.
You Gotta Know When to Golem
At the end of an episode of Krusty's show, Bart goes backstage to complain about an acid-spraying Krusty brand alarm clock. There, he finds the Golem of Prague, a creature from Jewish mythology. Krusty tells Bart that the Golem was sculpted from clay in the seventeenth century by a powerful rabbi, and would do anything written on a scroll and placed in his mouth. The Golem had been passed down through many generations and now works for Krusty. Bart steals the Golem by writing a command for him to come to his house at midnight, while Krusty prepares for a "Desperate Houseflies" sketch.
At midnight, the Golem shows up at the Simpson's house. From then on, Bart uses him to carry out his commands: swinging Principal Skinner up and down like a yo-yo until he splits in half, and kicking Homer in the balls (although he thought Bart wrote "walls" at first). Lisa, believing that the Golem doesn't like doing the biddings of others, commands him to speak to her. The Golem reveals that he feels guilty about being used to commit heinous acts. To make him feel better, the Simpsons create a female Golem out of Play-Doh. When Homer hears her voice, he tries to chop her with an axe, but the Golem stops him, saying that she is "made" for him. The two are married by Rabbi Hyman Krustofsky, and the female Golem convinces Chief Wiggum not to press charges with the promise of pan-fried latkes, a Jewish delicacy (she was going to explain what they were, but convinced Wiggum when she mentioned them being pan-fried).
The Day the Earth Looked Stupid
In 1938, the population of Springfield is fooled by Orson Welles' infamous War of the Worlds radio broadcast, believing the world has in fact been invaded. A mass panic breaks out, and the citizens begin rioting and destroying the town. Marge suggests they foil the aliens by cavorting in the mud naked. They do this until the next day, when Lisa tells the citizens that it was all a hoax. Outraged at being fooled, the citizens vow to not fall for such a trick again. Kang and Kodos find this to be the perfect opportunity for an actual invasion, and begin destroying what is left of the town.
True to their word, the town does not believe it is a real invasion and ignores it, even after Orson Welles shows up and tells them it is not staged and that they must do something. The segment ends three years later with Kang and Kodos looking over the ruins, mulling on what went wrong and why they weren't greeted as liberators as they rid Earth's weapons of mass disintegration during "Operation Enduring Occupation". The camera then reveals tht the earth has fallen victim to a nuclear fallout while the Ink Spots' version of "I Don't Want to Set the World on Fire" plays.
Behind the Laughter
The song during the opening title credits is "Gloomy Sunday" by Billie Holiday.
"The Day The Earth Looked Stupid" was originally supposed to end with Kang and Kodos making a direct reference to the war in Iraq as they observe the ruined remains of 1938 Springfield. While the Fox censors had no objections over the line, the producers and writers felt the reference was too obvious and had it cut to make the joke more subtle. The ending to the episode shares a number of similarities with the video game Fallout 3, although it predated its release by approximately two years. For example, at the end of the episode, the Ink Spots' 1941 version of "I Don't Want to Set the World on Fire" is played over the scene.