Continuity mistake: When Bugs is sitting on the bench in Central Park with the other out of work actors, he has stubble on his chin. When Bugs accepts Elmer's role as his sidekick in his vaudeville act, the stubble has disappeared.
Continuity mistake: When Bugs Bunny (dressed as the warden) says "Warm enough for you, Schultz?", there is a fountain pen holder on his desk that disappears in the next shot.