The Simpsons Season 21 Episode 4 - Treehouse of Horror XX Episode Title:Treehouse of Horror XX.Episode Description:Lisa becomes livid with Miss Hoover, and in a series of homages to classic Hitchcock sets out for deadly revenge. Next, Krusty's latest fast-food sandwich transforms news anchor Kent Brockman into an enraged zombie and twenty-eight days later, cannibal zombies have overrun Springfield. In the final frightening fable, Homer accidentally falls through a trapdoor in Moe's tavern and impales himself on the pipes of Moe's microbrewery. Moe serves the barflies a glass of delicious beer flavoured with Homer's blood and Homer, now half-man, half-brewing apparatus, returns for vengeance.