Continuity mistake: During the slow-motion sequence, Speedy slams the mallet on the cat's paw and leaves the mallet on the ground when he rescues the mouse. When he puts a stick of dynamite on the cat's tongue, the mallet has gone.
Continuity mistake: When Tom is placing a chicken under Spike's arm, Jerry takes a photo and you can see a trail of fake paw marks. When Jerry emerges from the dark room with copies of the photo, he takes one copy from the pile and has a look at it, but the picture shows no paw marks at all.
Continuity mistake: When Ralph is walking up the steps to his apartment, he has a present in his right hand. The present disappears when he goes through the doors, but re-appears when he enters the kitchen.
Continuity mistake: When Elmer is stabbing Bugs' hole with his spear, there are rabbit tracks around the hole. But when Elmer says "I'm going to kill the wabbit!" the rabbit tracks have disappeared.
Continuity mistake: When Daffy performs his time-step, there is a button on his waistcoat. But when he goes down on his knees, the button is missing.