Continuity mistake: When Casper the Caveman takes off his caveman's outfit to go swimming, he puts his outfit near the edge of the bank. After Daffy says that he can't swim, he reverses back onto the land and goes and collects his suit, but this time the suit is now much further away from the bank.
Continuity mistake: When the dog in the audience has his feet crushed by the hippopotamus sitting down on his chair, you can see that there is an empty chair next to the dog, but in the next shot the chair has disappeared.
Continuity mistake: Gloria (Eve Arden) caps her bitter statement by plucking something to eat with her fingers. As Anita's gramps arrives, she is eating off her plate with silverware. (00:03:25)