When one bullfrog wonders what's on the other side of a wall, nine more frogs happen by and, one by one, climb a mounting tower of frogs hoping to peer over. The tenth (a tiny tree frog) succeeds and spies an alligator, and they all tumble down. Wing's first children's book doesn't quite hop, but it does have a carefully framed text with a good variety of conversational gambits (``What have we here?''; ``Why are you all piled up like that?''). McGraw's striking full-bleed paintings, with frogs flung against tropical colors delineating the wall plus some structures and palms glimpsed beyond it, are of interest as pure design (and the frogs are countable). But he not only ignores the comic possibilities of their balancing act; in his arty arrangements of their two-dimensional forms, he defies gravity. An additional purchase with possible use for new readers. (Picture book. 3-7)