Approximately 3,200 types of amphibians on earth are less than six inches long and "weigh less than a box of animal crackers." The smallest frog is tinier than a thumbnail, while the largest amphibian, the Chinese giant salamander, can be as tall as a man and weigh about 60 pounds. The book opens with a description of amphibians, what traits amphibians like frogs and salamanders have in common, and how different amphibians survive in hostile environments. Basic behavior, physical characteristics and life cycles are covered in detail. High-quality photographs enhance the visual pleasure of the book, which is part of the "True Books" series about animals and includes books about birds and mammals. An index, definitions of key words and a list of additional resources, including organizations and online sites that specialize in amphibians, are included.