Little Hippo is the youngest in his family...and the smallest. Smaller than his parents and siblings. Smaller than his friends, too, from old Crocodile to giant Elephant. And even though everyone promises hell grow, Little Hippo doesn't want to wait. He wants to be big RIGHT NOW! But when he helps a creature even tinier than himself, Little Hippo learns that it's the size of his heart that counts most of all.