What is a young baby rabbit called?

The movie opens, innocently and deceptively, as a Baby Herman short subject, which in the realm of this film is revealed to be a "live action" slapstick short in the midst of production (after the manner of The Three Stooges). This introduces the film's title character, who plays the supporting comic foil to infant cartoon star (actually a grown man who appears to be a baby) Baby Herman. In the movie's milieu, cartoon characters are a cohabiting sapient species alongside human beings, though unlike them, are unbounded by the laws of physics when it's funny. The manager of Maroon Cartoons studios, R.K. Maroon (Alan Tilvern), is worried that Roger isn't at the top of his form because he thinks his wife, Jessica Rabbit (uncredited speaking voice by Kathleen Turner, singing voice by Amy Irving), is being unfaithful. He hires alcoholic private eye Eddie Valiant (Bob Hoskins) to investigate. Valiant goes to the Ink and Paint Club, a Toon-only revue, to see Jessica's act and to spy on her. He takes incriminating photos of Jessica playing playing pattycake (literally) with Marvin Acme (Stubby Kaye), owner of the Acme Company, which manufactures cartoon props and gags. Playing pattycakes is tantamount to infidelity in the eyes of a Toon. When Roger sees the photos, he becomes enraged. The next day, Marvin Acme is found murdered in the Acme warehouse, with a safe dropped on his head. Roger Rabbit is immediately accused, due to him having a motive and no alibi.