The German Shepherd in the film was Larry Cohen's own dog, and the red sweater sported by Yaphet Kotto in latter portions of the movie was also Cohen's--which Kotto then took and never gave back.
Susan Sarandon came in to audition for the Jeannie Berlin part, but was intimidated by Larry Cohen's normally docile German Shepherd, so much so that the audition had to be canceled.
In the commentary track, Larry Cohen reveals that footage of a supermarket employee slipping on a banana peel was actually a stock shot from an MGM picture whose title he can't remember. In reality, it was from the Connie Francis musical Looking for Love (1964).
Elaine May requested use of the footage of her daughter Jeannie Berlin in this movie to convince producers of The Heartbreak Kid (1972) (as well as writer Neil Simonhimself) that her daughter had actual acting ability and wasn't being put in the movie merely out of nepotism.