The first six-page section compares the giant Pacific octopus with the star-sucker pygmy octopus. The giant octopus can be up to sixteen feet across and weigh up to ninety pounds while the pygmy octopus is less than half an inch in size. Full-color photographs with informative captions show the creatures in their natural habitats and a map shows their locations. Inset boxes provide Fast Facts, such as "The pygmy octopus uses camouflage to hide from larger animals." The next two sections follow the same format. The sunflower sea star, a huge star fish, is compared to the live-bearing sea star, the smallest. The sunflower sea star lives in the deep waters of the ocean. It can grow to more than three feet across and may have as many as twenty-four arms. The tiny sea star, measuring less than half an inch across, lives only in Tasmania. The last section compares the whale shark with the spined pygmy shark. The whale shark, living only near the equator, is longer than a school bus. The pygmy shark lives in shallower water and grows to about seven inches in length. The book begins with a table of contents and a short glossary. It closes with a page about the blue whale, a bibliography, a list of Internet addresses, and an index. An appropriate introductory information book for young children. Part of the "Biggest vs. Smallest Animals" series. Reviewer: Phyllis Kennemer, Ph.D.