Dr. Jekyll and Mr. Mouse (1947)

Continuity mistake: When Jerry first becomes buff after drinking some of the milk and starts approaching Tom to beat him up, Tom sees a book and grabs it then hits Jerry. Before Tom grabs the book, it's yellow. When he grabs it, it's green.

Shaheed Simon

Continuity mistake: When Jerry drinks the poisoned milk that Tom placed outside his mouse hole, he seemingly drops dead and there is only a small amount of milk in the bowl. When Jerry goes back to drink some more milk later on, the bowl is now full again.

Continuity mistake: When Tom has finished pouring the milk into the bowl, he puts the cap back on the bottle. When he lifts up the plant and puts the bottle into the plant pot, the cap has gone.