Lizards are reptiles that generally have four legs, eyelids and external ear openings (though there are some exceptions). Their bodies are covered with scales; in some, the scales are rather large, while in others they are tiny and granular.  Some have very smooth and glossy scales.  Others have some of the scales modified into spines or horns.

A great many of the smaller lizard species eat insects and other invertebrates, but there are also species that are mostly vegetarian.  A few lizards have very specialized diets, such as the horned lizards that eat mostly ants. (Unfortunately, they do not eat the red imported fire ants!)

Lizards have developed some of the most bizarre bodies in the reptile world.  The frilled dragon of Australia has large folds of skin that open like an umbrella around its face to startle an enemy.  The true chameleons have tongues that can project out, much longer than their whole body, to stick onto an insect and pull it back to their mouths.  A few species, such as the Glass lizards, have evolved long bodies without legs.  However, they are not snakes; their head structure remains lizard-like, with eyelids, external ears, and lacking the snake’s modified jaw structures.

The largest lizards are the monitors.  They have relatively long necks, snake-like tongues, and are found from Africa through parts of Asia and through Indonesia and Australia.  The largest monitor is known as the Komodo dragon, which occasionally reaches lengths of nearly ten feet and is found on a few Indonesian islands.  In the wild, the saliva of these lizards contains some virulent bacteria and people have speculated that a large prey animal might be brought down by sepsis after being tracked by the monitor until it dies.  There is also some evidence that the Komodo and some other monitors are mildly venomous (though they have no fangs).

Whiptail lizards like this one are very fast, active on hot days, and have tails that can break off if grabbed

Broad-headed skink

Texas horned lizard