The glass lizards or glass snakes are a genus, Ophisaurus (from the Greek 'snake-lizard'), of reptiles that resemble snakes, but are actually lizards. Although most species have no legs, their head shapes, movable eyelids, and external ear openings identify them as lizards. A few species have very small, stub-like legs near their rear vents. These are vestigial organs, meaning they have evolved and are no longer in use. These animals are also known as jointed snakes. They reach lengths of up to , but about two-thirds of this is the tail. Glass lizards feed on insects, spiders, other small reptiles, and young rodents. Their diets are limited by their inability to unhinge their jaws. Some glass lizards give birth to live young but most lay eggs.