Right after the scene where Todd knocks over the pail of milk, the woodpecker is chasing after the caterpillar. When the caterpillar goes into the tree he is pecked at once, then three more times. The last three pecks form the shape of a mickey head...
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In the beginning of the movie when Todd and Copper become friends and start to play hide and go-seek, if you look at the bush that Todd is hiding in you can see 3 berries which form the famous Mickey Mouse head.