Treehouse of Horror XX
The Simpsons: Season 21, Episode 4
Lisa sets out for revenge against Miss Hoover, zombies overrun Springfield after Krusty sells dubious burgers, and Homer becomes a half-man, half-brewing apparatus after falling through a trap door at Moe's.
Show: The Simpsons
Air date: October 18, 2009
Written by: Daniel Chun
Directed by: Mike B. Anderson; Matthew Schofield
Episode no: Season 21; Episode 4