Premise: Monkey Business is a 1952 American screwball comedy film directed by Howard Hawks and written by Ben Hecht, which stars Cary Grant, Ginger Rogers, Charles Coburn, and Marilyn Monroe. To avoid confusion with the famous 1931 Marx Brothers film of the same name, this film is sometimes referred to as Howard Hawks' Monkey Business.
Hypothesis: The Marx Brothers had a movie with an animal in the title.