How to Play Animal Upon Animal Junior

About My Very First Games: Animal Upon Animal Junior, from BoardGameGeek:

Things are getting wildly wobbly as the animals create a big stacking tower. Who will climb on whom? The die decides. But whether the animal stack stays standing or not is up to the players. They stack Animal upon Animal in three new games for young stackers. In the third game, they work cooperatively to race against the crab, training their dexterity skills with play. May the best stacker win! Note: Not the same game as My Very First Games: Animal upon Animal. This game has new rules, new name, new art, new pieces.