The black spiny-tailed iguana can run at a maximum speed of 21 miles per hour, making it the worlds fastest lizard! Iguanas are also agile climbers and will race up trees to find the leaves, fruit, and flowers that make up most of their diet. These are some of the fascinating facts kids will discover as they learn all about these speedy lizards. Eye-popping photos and clear, easy-to-read text will engage emergent readers as they discover the anatomical features that help black spiny-tailed iguanas reach fast speeds. A Speed-o-Meter graphic compares the iguanas top speed to that of other animals.