Crocodiles are an order of amniotic land vertebrates. There are around 26 different species, which are divided into 8 to 9 different genera in the three families of true crocodiles, alligators, including caimans, and gavials.

Crocodiles live in rivers and lakes in the tropics and subtropics; the inguinal crocodile can also live in the sea and is often found on the coasts of Australia and various islands in South-East Asia. Their lizard-like, primitive appearance is one of many adaptations to their lifestyle as aquatic ambush hunters. They have high-set eyes and nostrils, which allows them to submerge almost completely and still breathe and keep an eye out for prey.
Crocodiles have a back armour made of bone plates, which is why they are also known colloquially as armoured lizards.