Book excerpt: An animal with smooth, gray skin jumps from the ocean waves. Its tail waves up and down before it quickly dives again. Did you just see a dolphin? Or was it a porpoise? These animals look very similar, but they are different. Read this book to become an expert at telling these look-alikes apart! Learn the fascinating differences between similar animals in the Animal Look-Alikes series—part of the Lightning Bolt BooksTM collection. With high-energy designs, exciting photos, and fun text, Lightning Bolt BooksTM bring nonfiction topics to life!