You might think that a playground offers few places for a hippopotamus to hide, and you would be right; playful Harry the hippo is charming in his attempts to conceal himself beneath a seesaw and a slide, or even—defying the laws of physics—atop a swing set. Kenny Harrison's illustrations are full of simple colors and shapes, and prereaders can assist Harry's two young friends as they (rather easily) uncover the hippo's hiding places.