Chameleons are a distinctive and highly specialized clade of Old World lizards with 202 species described as of June 2015.
These species come in a wide range of colors, and many species have the ability to change colors.
Chameleons are distinguished by the shape of their feet; their very extensive, highly modified, rapidly extrudable tongues; their swaying gait; and crests or horns on their brow and snout.
Most species, the larger ones in particular, also have a prehensile tail.
Chameleons' eyes are independently mobile, but in aiming at a prey item, they focus forward in coordination, affording the animal stereoscopic vision.
Chameleons are adapted for climbing and visual hunting and they live in warm habitats that range from rain forest to desert conditions, various species occurring in Africa, Madagascar, southern Europe, and across southern Asia as far as Sri Lanka.
Madagascar is home to about half the world's species of chameleons, including both subfamilies, typical chameleons (Chamaeleoninae) and dwarf chameleons (Brookesiinae).
They also have been introduced to Hawaii, California, and Florida, and often are kept as household pets.
Reference: Wikipedia