Lizards are a widespread group of reptiles, with over 6,000 species, The group is paraphyletic as it excludes the snakes and frogs which are also squamates. Lizards range in size from chameleons and geckos a few centimetres long to the 3-meter long Komodo dragon.

Most lizards are quadrupedal, running with a strong side-to-side motion. They are often territorial, the males fighting off other males and signalling, often with bright colours, to attract mates and to intimidate rivals. Lizards are mainly carnivorous, often being sit-and-wait predators; many smaller species eat insects.

Lizards make use of a variety of antipredator adaptations, including venom, camouflage, reflex bleeding, and the ability to sacrifice and regrow their tails.