Continuity mistake: When Porky is making his breakfast on the stove, the direction of the frying pan handle changes between shots.
Continuity mistake: When Daffy hands Porky a shotgun, he says "It ain't gonna do you any good!" and pulls down a sign saying "Duck Season Opens Today!" You can see that the sign has a cord at the bottom of it and an exclamation mark, but when we see Daffy walking back from Porky a few shots later, the cord and exclamation mark have both disappeared.
Continuity mistake: When Porky is about to put the pole down into the ground, you can see that there's nothing behind him, but in the next shot trees have suddenly appeared.