Reptiles are cold-blooded animals.  They typically lay hard shelled eggs and have skin covered with scales or a bony external plate. They either have four legs or descended from four limber ancestors. Some examples of reptiles are: alligators, crocodiles, caimans, gavials, lizards, snakes, turtles, and tortoises. The science dealing with reptiles is called herpetology.

Amphibians are animals that can live on land or in water. They spend part of their lives under water breathing through gills and part of their lives on land breathing with lungs. Amphibians are characterized by glandular skin and no scales. Most amphibians lay eggs in the water.  Most have four legs but some have no legs. Some examples of amphibians are: frogs, toads, salamanders, and newts.