Foster's Home for Imaginary Friends S05 E09 Nightmare on Wilson Way

Bloo tries the old peanut brittle can filled with snakes trick, thinking it as the ultimate Halloween prank after strapping Mac to his bed so as to not allow him to go trick-or-treating because of his sugar rushes. However, when Mr. Herriman tries his trick, Bloo thinks it has gone awry, and Mr. Herriman becomes a zombie, much to the shock of the other residents.