"Treehouse of Horror XVII" is, as the name indicates, the seventeenth Treehouse of Horror episode of The Simpsons. It is also 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 radio broadcast.
The episode begins with a parody of Tales From The Crypt with Mr. Burns as The Crypt Keeper. The scene begins in a dungeon room where a crypt opens and after several waves of rats, snakes, spiders and rabbits crawl out of it, the Crypt Keeper sits up in it. He proclaims himself to be the master of scare- amonies much to the delight of the zombie Smithers. A bound Moe interrupts in protest and is killed in an iron maiden, his blood spilling out onto the floor and spelling out Treehouse of Horror XVII. Moe himself takes delight in this and proclaims "A Ho Ho, My blood is a genius! Fancy Roman numerals and everything!"
Married to the Blob
In a parody of 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 rumbling from hunger, Homer eats all the food in the house. Homer also eats the cat and attempts to eat Bart but is prevented by Marge. After that, he finds teenagers having a barbecue sauce fight, then sees one who fell into the fire, and eats that teen, declaring "Don't worry, I'll savor you!" before he does so. Then he ends up at the Oktoberfest. He eats four fat Germans then says "must eat more fat people, thank god I'm in America". Then in a music segment parodying the song "Baby got Back", he is shown now seriously fat walking around, looking for food. Now a fat green blob, rampaging through the streets of Springfield, eating all the fat people he can find.
As Homer samples bus passengers as if they were candies, Dr. Phil McGraw shows up with the Simpson family. He 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. The homeless people enter the shelter, only to find themselves in Homer's gut.
You Gotta Know When to Golem
In a parody of The 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 in the seventeenth century, the Golem was sculpted out of clay by a powerful rabbi. The Golem would do anything written on a scroll and placed in his mouth. He 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 home at midnight, while Krusty is wearing a mask in preparation 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 (though he at first thought Bart wrote walls). Lisa thinks the Golem doesn't like doing the biddings of others and feeds him a scroll reading "Speak". 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 up 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 had him at 'pan-fried.')
The Day the Earth Looked Stupid
In a parody of Fallout and the War of the Worlds confusion, The population of Springfield, circa 1938 (during the Great Depression), are fooled by Orson Welles's infamous War of the Worlds radio broadcast and believe the world has been invaded. A mass panic breaks out, and the citizens begin rioting and destroy the town. Marge suggests they foil the aliens by cavorting in the mud naked like animals. So they do this all day until the next day, Lisa notifies the citizens that it was all a hoax and, angry at being fooled, the citizens of Springfield vow to not fall for such a trick again.
Kang and Kodos agree this is the perfect time for a real invasion, and begin destroying what's left of the town. True to their word, the town does not believe that it's a real invasion and ignores it, although Orson Welles comes to Springfield, admits it is not a staged act, and begs them to do something. Unfortunately, they don't, and 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 (WMD) during "Operation Enduring Occupation", a parody of the real military operation, "Operation Enduring Freedom". The camera then pans out to reveal the earth has fallen victim to a nuclear fallout while "I Don't Want to Set the World on Fire" by The Inkspots plays in the background, before cutting to the credits.
"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 Bethesda's Fallout 3 though "The Day the Earth Looked Stupid" predates the release of this video game by approximately two years. For example, at the end of the episode, the scene is post-apocalyptic and The Ink Spots' 1941 "I Don't Want to Set the World on Fire" composes the soundscape.