The head-crushing scene was based on a time when Lloyd Kaufman was backing a car out of his garage and accidentally hit his younger sister. Nobody was harmed, but the memory haunted him for years.
While shooting in Shinbone Alley, a homeless man stole a prop gun from one of the trailers and threatened the crew.
The violent-looking crushing of a child's head in the movie was accomplished by injecting a melon with corn syrup and red food dye. A wig was placed on the melon and it was fitted onto a dummy. Though cheap, the effect is highly unsettling.
Larry Sulton, who played Frank, only had one arm. During the scene at the Mexican restaurant, one can see that his right arm is a prosthetic. He never moves or uses it until Toxie rips it off.