Iguanas are some of the largest lizards found in the Americas, with their whip-like tail making up about half of that length. Like other reptiles, iguanas are cold-blooded, egg-laying animals with an excellent ability to adapt to their environment. Iguana species vary greatly in size, color, behavior. Some species, like the green iguana, are quite common; others, like Fiji banded iguanas, are endangered. Two iguanas native to San Diego County are the desert iguana and the chuckwalla.