Dreams of wings and Mexico light up a caterpillar’s imagination after a brief conversation with a passing monarch butterfly. Shaking off the mockery of his clueless caterpillar buddies and picking up some Spanish phrases with help from Edna, a supportive bookworm, Oscar eagerly bundles his way into “that long caterpillar nap” when the time comes. He wakes up with wings but not the ones he’d expected. No matter: Shaking off new predilections for light bulbs and woolen socks (“Más medias, por favor”) he heads South—and is last seen perched on a flower below glorious clouds of golden butterflies, sporting a sombrero and penning a post card: “Dear Edna: I thought like a butterfly. Love, Oscar.” Elwell outfits his chubby larval cast in Our Gang–style caps, more or less human faces with small, red clown noses, diminutive wings and outsize personalities. Just another victory for free will over predestination, with particularly engaging pictures. The afterword supplies moth and butterfly facts. (Picture book. 6-8)