California Red Legged Frog

The California Red-legged Frog is a moderate to large (4.4-14 cm) species of frog. The dorsum is brown, grey, olive or reddish color with black flecks and dark, irregular, light-centered blotches and is coursly granular. There is a dark mask with a whitish border above the upper jaw, and black and red or yellow mottling in the groin. The lower abdomen and the underside of its hindlegs are red. Males can be recognized by their enlarged forelimbs, thumbs, and webbing. Juveniles have more pronounced dorsal spotting, and may have yellow, instead of red markings on the underside of the hindlegs. A characteristic feature of the red-legged frog is its dorsolateral fold, which is visible on both sides of the frog extending roughly from the eye to the "hip." The California red-legged frog was listed as a threatened species by the United States Fish and Wildlife Service in 1996.

Source: http://en.wikipedia.org/wiki/California_Red-legged_Frog