During What's Up Doc?, Al Jolson, Jack Benny, Eddie Cantor and Bing Crosby appear, through caricatures, in a park with Bugs, all of them out of work. Jolson spots Elmer, a big vaudeville star, and tells the others that Elmer is looking for a partner. The four then do their trademark phrases/songs, but Elmer ignores them. When the "fathead" reaches Bugs, he says, "Why are you hanging around these guys? They'll never amount to anything."