A Night at the Opera (film) DVD commentary. But this could not have occurred, because Sam Marx had died in 1933, during pre-production of "Duck Soup", two years before "A Night at the Opera" was released. The rumor arose because Frenchy had had such a cameo appearance in the Marx Brothers' earlier "Monkey Business". There is, however, a reference to the Marx Brothers' mother, Minnie Marx, during the stateroom scene, in which a woman asks, "Is my Aunt Minnie in here?" Part of the concept of casting the Marx Brothers as stowaways on a ship was recycled from "Monkey Business". As Groucho's and Margaret Dumont's characters
Marx Brothers "Duck Soup", with Lucy dressed up as Harpo. Lucy had worked with the Marxes when she appeared in a supporting role in an earlier Marx Brothers film, "Room Service". Chico once appeared on "I've Got a Secret" dressed up as Harpo; his secret was shown in a caption reading, "I'm pretending to be Harpo Marx (I'm Chico)". The Marx Brothers were spoofed in the second act of the Broadway Review "A Day in Hollywood/A Night in the Ukraine". In the 1989 film "Indiana Jones and the Last Crusade", Professor Henry Jones (Sean Connery) mails his diary to his son Indiana