What doesn't have muscles but can still move? What helps our body get rid of dangerous toxins? The P Word: A Manual for Mammals is the definitive pre-puberty guide to the penis for young people. This easy-to-understand manual gives readers an overview of how and why penises work--and how to keep them healthy for years to come. More than just a boring anatomy lesson, it weaves scientific insights and surprising mammal facts together with accurate and engaging illustrations. Written by award-winning bioengineer David Hu and illustrated by Ilias Arahovitis, this fascinating and groundbreaking work draws on both human and animal biology to introduce kids to an amazing organ. Refreshingly gender-neutral and inclusive in its language, this book will educate and entertain readers young and old.