Continuity mistake: When Tom is sneaking up on Jerry after he has taken the piece of cheese from the fridge, Tom takes the shade off the lamp and puts it on his head. At this point you can see the lamp is behind Jerry, but in the next shot it disappears.
Continuity mistake: When Bugs puts up a "Camp Here" sign near his hole, you can see there is nothing behind the sign, but in the next shot a tree has suddenly appeared.
Continuity mistake: When Jerry appears from the hair of the toy lion, you can see that behind him there is a decoration and some purple baubles. In the next shot, the decoration has disappeared and the baubles are now much closer to the lion.