This frog grows in size to between five and nine cm in length. It is a brown or green colored frog, with 2 or 3 rows of irregularly placed dark spots between conspicuous ridges. Also, there are numerous additional rounded dark spots on sides of the body. This species is found in or near virtually all standing water bodies, feeding on mostly invertebrates. In summer they disperse into fields and meadows, returning to water in the fall.
Northern leopard frogs breed in any standing water, starting in mid spring. This species is extremely prolific and abundant and because of this, it is extremely important in aquatic food chains.