"Treehouse of Horror XIX" is a Halloween-themed episode form the twentieth season of the animated comedy series The Simpsons. It was first broadcast in the United States on the Fox Network on November 2, 2008.
In common with all previous "Treehouse of Horror" episodes, the program is made up of three self-contained stories; "Untitled Robot Parody", "How to Get Ahead in Dead-vertising" and "It's the Grand Pumpkin, Milhouse". The first story is a parody of the 2007 movie Transformers. In the second story, Homer Simpson is persuaded to murder several celebrities so that their images can be used for free in commercials. The final story is a parody of the 1966 Halloween TV special It's the Great Pumpkin, Charlie Brown.
Homer Simpson tries to vote for Barack Obama in the 2008 US presidential election but the voting machine is rigged and only registers votes for the other candidate John McCain. After six failed attempts to vote for Obama, Homer declares that he has to do something about the machine, saying, "Must warn President McCain!" Homer is sucked into the machine and his dead body is spat out. An "I voted" sticker is then placed on Homer's forehead.
"Untitled Robot Parody"
For Christmas, Bart Simpson buys his sister Lisa a toy car for her Malibu Stacy doll. The car is really a robot which changes other machines in the town of Springfield into robots too. The robots form two sides and fight against each other.
Marge Simpson asks the robots why they are fighting. They have to admit that they have forgotten the reason behind their disagreement. They agree to put their differences aside and work together on a new project - conquering the human race. The segment ends with the robots using the people of Springfield as the figurines in a giant foosball game.
"How to Get Ahead in Dead-vertising"
Homer Simpson takes his baby daughter Maggie to daycare. The baby is upset about being separated from her parents, so Homer shows her a mural of Krusty the Clown to cheer her up. The real Krusty the Clown arrives and sandblasts part of the mural, because it is an unlicensed use of his image. Homer is angry with the clown for upsetting his daughter. He repeatedly shoves him, eventually causing Krusty to land in a wood chipper which kills him.
Having heard about how he caused the death of Krusty the Clown, some advertising executives approach Homer. The images of dead celebrities can be used in advertising without seeking permission from anybody and without having to pay anybody. Dead celebrities can also be used to advertise products which they refused to endorse while they were alive. The advertising executives persuade Homer to kill other celebrities, including George Clooney, Prince and Neil Armstrong.
In Heaven, the dead celebrities discuss the use of their images in commercials. Apart from Abraham Lincoln, who enjoys a commercial which shows him kissing George Washington, they are all angry about how their images are being used. Krusty leads them back to Earth where they attack all those who have made a profit from the commercials.
Homer Simpson is killed by the dead celebrities but gets his revenge on them by locking them out of heaven, leaving him alone with a very friendly Abraham Lincoln.
"It's the Grand Pumpkin, Milhouse"
On Halloween night, the boy Milhouse is sitting alone in a pumpkin patch, waiting for the Grand Pumpkin to arrive. Knowing that the Grand Pumpkin does not exist and that Milhouse will end up getting upset, Lisa Simpson sits with him for a while. However, when she sees the other children of Springfield (and the aliens Kang and Kodos) enjoying a Halloween party, Lisa leaves.
Milhouse begins to cry. His tears, coupled with his sincere belief, cause the Grand Pumpkin to magically come to life. When he discovers that people celebrate Halloween by carving pumpkins into jack-o-lanterns, the Grand Pumpkin is outraged by how humans have treated his kind. He goes on the rampage, eating all the people that he comes across.
Realising that Milhouse has the power to make fantasy characters become real through his belief, Lisa Simpson tells him about the Thanksgiving character Tom Turkey. Milhouse's sincere belief makes Tom Turkey come to life. The turkey fights and kills the Grand Pumpkin, releasing all the people that the pumpkin had eaten. However, when Tom Turkey finds out that turkeys are eaten on Thanksgiving, he begins to take revenge by eating the children of Springfield.