African dwarf frogs live their entire lives underwater, but need to rise to the surface to breathe air because they have lungs and not gills. These frogs are small in size and do not weigh more than a few grams. These frogs vary in color, for the most part ranging from olive green to brown with black spots. The average life expectancy of these frogs is 5 years, but they can live as long as 20 and grow to 2½ inches long. When young, African dwarf frogs can be mistaken and sold as African clawed frogs, African frogs of the genus Xenopus, which are larger and more aggressive than the dwarf.