Amphibians spend their lives in water and on land. There are more than 4,000 different kinds of amphibians. Members of this animal class are frogs, toads, salamanders, newts, and caecilians or blindworms.
The answer is Amphibians.
The word amphibian came from a Greek word called "amphibios" which is composed of two root words :
1. "amphi", meaning "of both kinds," and 2. "bios", meaning "life." i.e. they can lead a dual life.