Revealing mistake: When Speedy Gonzales is watching Sylvester drink Tabasco sauce from the tank that sends him miles into the horizon, watch Speedy's tail: it disappears before the scene ends.
Continuity mistake: When Speedy Gonzales makes Sylvester jump, you can see that Sylvester's chest is shaven, but when he is chasing Speedy in the next shot, his chest is now its usual white.