Scientific name: Rana luteiventris
- Abundant and best known amphibian in Yellowstone.
- Maximum length is 3.2 inches; newly metamorphosed juveniles are less than one inch long.
- Upper surface of the adult is gray-brown to dark olive or even green, with irregular black spots; skin is bumpy; underside is white splashed with brilliant orange on the thighs and arms on many, but not all, individuals.
- Tadpoles have long tales and may grow to 3 inches long.
- Found all summer along or in rivers, streams, smaller lakes, marshes, ponds, and rain pools.
- Lays eggs in stagnant or quiet water, in globular masses surrounded by jelly.
- Breeds in May or early June, depending on temperatures.
- Tadpoles mature and change into adults between July and September.
- Tadpoles eat aquatic plants; adults mostly eat insects, but are highly opportunistic in their food habits (like many other adult amphibians).