Amphibians are cold-blooded animals, and most undergo metamorphosis. They also lay eggs underwater. They may breathe through gills, lungs or through their skin. They are vertebrates and have slimy skin without scales. Most live in moist places or in water itself.

There are over 6,500 species of amphibians.

One example of an amphibian is the Mexican burrowing caecilian, also known

as These caecilians look much like giant earthworms, but

they actually do have a backbone.

Another example of an amphibian is the leaf green tree frog, also known

as This species is only found in far eastern Australia.

http://www.amphibianark.org/education/what-are-amphibians/

http://www.aitc.sk.ca/saskschools/animals/amphib.html