The horse-like animals had two feet instead of four because it was easier and cheaper to animate.
No pencil tests were done on the film because of its low budget. The drawings went straight to the final product.
The line "They killed Fritz! They killed Fritz!" is a reference to Robert Crumb killing off Fritz the Cat in his underground comic book series. Ralph Bakshi directed the film adaptation of Fritz le chat (1972). Bakshi is quoted as saying, "I named the character Fritz in "Wizards," just so I could scream 'They killed Fritz!' To kill such a cat would make Don Marcus commit suicide."
Susan Tyrrell specifically requested to be uncredited for her role as the narrator, believing that performing in an animated film would be detrimental to her career. Ralph Bakshi claims that she approached him years later and revealed that the movie had actually been instrumental in securing her many subsequent roles and that she regretted her request.
The "religious" articles in the temple include pinball machines, a Coca-Cola sign, a catcher's mitt, an Oscar statuette, a jukebox, and a gold front grill from a Rolls Royce.