Continuity mistake: When Moon Yu, the cow, had all the milk drained from him and he fell on his back, there is no bush behind him. But in the next shot there is one. Plus, watch his tail as Chosen walks away. As it sways from side to side it disappears.
Continuity mistake: When Betty receives the letter from the evil council, look at his jacket. It has long sleeves, but when he stomps the letter to the table, the sleeves disappear.
Continuity mistake: Various times in the movie when it shows the Crane school from a distance, the bush in front constantly changes sides and positions on the screen.