Puss n' Toots (1942)

Continuity mistake: When Jerry runs onto the record player, he runs next to a button panel and there are four buttons on it: Fast, Stop, Start and Change. But when he is pressing random buttons later on in the cartoon, a "Record" button has been added and the "Change" button has disappeared.

Continuity mistake: When Tom is smoothing down his hair while at the dressing table, he uses a brush to flatten down a hair, but when we see Tom in the next shot, the brush is nowhere to be seen.