This fanciful large-trim early reader pairs McPhail's gentle pen-and-ink and watercolor illustrations with an extremely limited vocabulary ("A cow can jump. / A hippo can jump. / We can jump"). The seeming weightlessness of the various creatures in the pictures lends the book a pleasing silliness--particularly when the cow jumps over the moon and the hippo happily bounces along--but it doesn't overpower the simple reading lesson.