Frogs are amphibians and their relatives are toads and salamanders.

The word "amphibian" means "double-life" because many amphibians spend part of their lives in water and part of their lives on land.

Amphibians have been around a long time - something like 350 million years! But the first frog appeared about 190 million years ago.

Frogs are known for leaping. The record for a frog leap is 17 feet in one jump!

The famous American writer, Mark Twain, wrote a funny story called "The Celebrated Jumping Frog of Calaveras County."

Because frogs don't have a shell, scale or dry skin, most amphibians live in damp conditions so they won't dry out.

Frogs go through major changes as they grow up. They start out as eggs, which turn into tadpoles, which don't look much like frogs! They change again into froglets and then become adult frogs. This process is called metamorphosis - a word Humphrey definitely hopes is never on his vocabulary test!