For Groucho Marx's performance of "'Lydia, the Tattooed Lady", additional lyrics were written by lyricist E.Y. Harburg exclusively for screenings of the film for Allied servicemen in European war zones. The special lyrics included the line "When she stands the world grows littler; When she sits, she sits on Hitler.' The version of the song featuring the special lyrics was filmed, and included in prints of the film distributed in Great Britain and France. The version of the song containing the special lyrics was greeted with marked enthusiasm during screenings in those countries.
Buster Keaton worked on the film as a gag man. His career was on the downside and he was forced to work for scale. His complex and sometimes belabored gags (recalled in the book "Groucho, Harpo, Chico and Sometimes Zeppo") did not work well with The Marx Brothers' brand of humor, and was a source of friction between the comedian and the brothers. When Groucho called Keaton on the inappropriateness of his gags for the team, Keaton responded, "I'm only doing what Mr. Mayer [MGM chief Louis B. Mayer] asked me to do. You guys don't need help."
Groucho Marx was fond of recounting how the original owner of the "gorilla skin" used in the film was so incensed when the stunt man wearing it poked ventilation holes in it with an ice pick that he took his suit and walked off the picture, forcing the producers to hastily rent an orangutan skin as a replacement. For this reason, Groucho claimed, the gorilla gets bigger and smaller from shot to shot. The man in the gorilla suit is in fact Charles Gemora, well-known movie sculptor and gorilla artist, wearing his own custom-made suit.
Groucho says "There must be some way of getting that money without getting in trouble with the Hays office." The Hays office (Named after Will Hays) was the Hollywood censorship board from 1930-1934. However, Joseph Breen replaced Hays in 1934, so the correct line should be "There must be some way of getting that money without getting in trouble with the Breen office."