Hungry Are the Damned (Treehouse of Horror, 1990)
The Simpsons’ resident aliens Kang and Kodos are a Treehouse staple for good reason, but their first proper appearance in the very first Halloween special still remains a high point. Comedic misunderstanding! The twist that the Rigellians actually did want to be nice to the humans they’d abducted! The true horror that maybe Lisa isn’t always right! And then, of course, the To Serve Man bit.
