LGM
Little Green Men, a reference to extraterrestrial intelligent life of a generally humanoid shape. Originated with early to mid-20th century science fiction characterizations and newspaper references to reports of supposed contact between humans and aliens.
... and at the end of the flick*, all these weird-lookin' LGMs come out of the spaceship and kinda wander around, like they're all high or somethin'. Hey, maybe that's what all that smoke is! The LGMs came to earth for the pot!

*Close Encounters of the Third Kind