Continuity mistake: When Dale is on the Christmas tree, he takes a green ball and throws it at Pluto. But in the next shot, Pluto catches a red ball, followed by a green ball.
Continuity mistake: Mickey Mouse uses an axe to cut down a tree for Christmas. Each chop he makes is horizontal, but when the tree falls over, the lower part of the trunk comes to a point, and the stump remaining in the ground has disappeared.
