X-Books are for kids who love facts—especially in bite-sized portions and about fascinating, true subjects. As plentiful images and graphical representations stimulate visual perception, readers will be drawn into learning how to use informational texts. Each title is framed by a signature Top 5 countdown feature that not only serves as an example of sequential order but also narrates a brief story within the main topic: in X-Books: Reptiles, these sidebars summarize the extraordinary abilities and features of some of the most intriguing reptiles in the animal kingdom. Count down the world's most extreme reptiles, and launch a lifetime of reading without limits! A countdown of five of the most fascinating crocodiles provides thrills as readers learn about the biological, social, and hunting characteristics of these web-footed, swimming reptiles.