Month by month, a hermit crab gathers other sea creatures (anemone, starfish, coral, etc.) to decorate his shell home; as the year ends, it is comfortably familiar and suits him perfectly--but (as often happens with human habitations in young readers' experience) has become too small. Rueful but undaunted, he gives it to a smaller crab and chooses a larger shell, "plain" but just right for a new cycle of additions. Though anthropomorphized in the text, Hermit Crab's behavior (if not the number of his legs) is authentic to the species, and Carle even includes some brief explanatory notes about him and a half-dozen of the other creatures he encounters. His illustrations are outstanding: richly textured, bright areas of deep color are crisply cut to form bold shapes deployed against stark white. The style will be familiar to Carle's admirers, but has been used to particularly good advantage here; the portrayal of the undersea world is in no sense realistic, but the illustrations convey the beauty and magic of that world. Fine for picture book hour or private sharing.