I'm a Frog - Elephant and Piggie, Bk 20 Author:Mo Willems Gerald is careful. Piggie is not. Piggie cannot help smiling. Gerald can. Gerald worries so that Piggie does not have to. Gerald and Piggie are best friends. In I'm a Frog! Piggie has some ribbiting news! Can Gerald make the leap required to accept Piggie's new identity?