David Miller Director Groucho Marx Detective Sam Grunion Actor Harpo Marx Harpo Actor Chico Marx Faustino Actor Ilona Massey Madame Egelichi Actor Vera-Ellen Maggie Phillips Actor Marion Hutton Bunny Dolan Actor Raymond Burr Alphonse Zoto Actor Bruce Gordon Hannibal Zoto Actor Melville Cooper Throckmorton Actor Leon Belasco Mr. Lyons Actor Paul Valentine Mike Johnson Actor Eric Blore Mackinaw Actor Marilyn Monroe Grunion's Client Actor Lester Cowan Producer Mary Pickford Producer Frank Tashlin Screenwriter Mac Benoff Screenwriter Ann Ronell Original Music William C. Mellor Cinematographer Albrecht Joseph Film Editing Basil Wrangell Film Editing Robert Cowan Nava Casting Gabriel Scognamillo Production Design Casey Roberts Set Decoration