One day Joe, an exuberant giraffe, hears a commotion coming from another part of the famous cageless zoo he calls home. Joined by his small, green, slightly more serious turtle friend, Sparky, Joe discovers the source of the hullabaloo: a group of children -- or noisy short people, as Joe and Sparky call them -- having a party. Inspired, Joe decides to throw a party for his pet worm, Wiggy. There's just one problem: Sparky is not entirely sure if Wiggy even exists!

A surprising idea -- The perfect present -- The uninvited guest -- Wiggy was here.