Marx Brothers "The Cocoanuts" (1925–1926) and "Animal Crackers" (1928–1929). Playwright George S. Kaufman worked on the last two and helped sharpen the brothers' characterizations. Out of their distinctive costumes, the brothers looked alike, even down to their receding hairlines. Zeppo could pass for a younger Groucho, and played the role of his son in "Horse Feathers". A scene in "Duck Soup" finds Groucho, Harpo, and Chico all appearing in the famous greasepaint eyebrows, mustache, and round glasses while wearing nightcaps. The three are indistinguishable, enabling them to carry off the "mirror scene" perfectly. The stage names of the brothers (except Zeppo) were
Marx Brothers Cream" sketch. In a 1969 interview with Dick Cavett, Groucho said that the two movies made with Thalberg were the best that they ever produced. Despite the Thalberg films' success, the brothers left MGM in 1937; Thalberg had died suddenly on September 14, 1936, two weeks after filming began on "A Day at the Races", leaving the Marxes without an advocate at the studio. After a short experience at RKO ("Room Service", 1938), the Marx Brothers returned to MGM and made three more films: "At the Circus" (1939), "Go West" (1940) and "The Big Store" (1941). Prior to the release