Rabbit Test is a 1978 American comedy film about the world's first pregnant man, directed and co-written by Joan Rivers and starring Billy Crystal in his film debut. This was the only directing effort by Joan Rivers, who also plays a nurse in a brief scene, while her daughter Melissa Rivers also has a bit part. Rivers' husband, Edgar Rosenberg, was producer. It was the only theatrical feature to be scored by the team of Mike Post and Pete Carpenter. Michael Keaton made his feature film debut in a small non-speaking role.