There are frogs living in Auntie Mabel’s garden. She finds some frog spawn floating in her pond and describes how the eggs develop into tadpoles which grow into frogs. She tells the story of the tadpole who thought he was a fish until, to his horror, he began to grow legs. Auntie Mabel and Pippin fly in Spotty Plane to a zoo where they meet a giant African bullfrog and a green Australian tree frog.