Amphibians

Amphibians are a group of creatures that are able to live both on land and in the water. They have existed for millions of years and are found everywhere but Antarctica and Greenland. Frogs are the most widespread amphibians, surviving in deserts, rain forests, and mountainous regions. Most amphibians breed in water, where they lay eggs that develop into tadpoles. Tadpoles breathe through gills until they develop lungs for breathing on land; this process is called metamorphosis. The name amphibian is derived from Greek amphibios, meaning "living a double life" - for the ability to live in both aquatic and terrestrial habitats. Despite the name, there are actually some species that are permanent land dwellers and others with a completely aquatic mode of existence.