Originally, the ending was going to have Cartman block out the sun in Smiley Town. However, because Trey Parker and Matt Stone were informed by Kyle McCulloch that it was done in The Simpsons (1989) (Season 6, Episode 25), the idea was scrapped. This experience became the basis for the season six episode, 'The Simpsons Already Did It'.
This episode includes several movie parodies from "Children of the Corn", "Lord of the Flies", "Logan's Run", "Pet Sematary",and "Mad Max, Beyond Thunderdome".
"Spaceman Spiff" (Mark's nickname for Craig based on his costume) is one of Calvin's fantasy characters from Bill Watterson's comic strip, Calvin and Hobbes. Butters/Professor Chaos' performance references another of Calvin's fantasy characters, Stupendous Man.
The "following hot presentation for mature audiences only" is a Terrence and Phillip presentation. You can see the tops of their heads when Cartman stands in front of the TV.
This episode is heavily inspired by the original Star Trek episode "Miri" (1966), in which a society has been taken over by children, and the earlier period is referred to as "the before time". The man's final impassioned speech also spoofs the overdramatic speeches of Captain Kirk.