Muskrats (Ondatra zibethicus) are easily recognized by their moderate size, their blunt head, and small non-descript ears and eyes. Adult muskrat weigh between 2.5 and 4 pounds, and total length may range from 23-26 inches, with a tail length of 8-11 inches.

A scaly, laterally compressed tail with a fringe of coarse hair along the underside of the tail is a feature muskrats share with no other New York State mammal.

They possess large hind feet with partial webbing in between their toes with a row of coarse hairs along the outer edge of each foot. Their fur can vary in shades of brown and in some cases black and consists of a soft, dense undercoat with an interspersion of longer, coarse guard hairs.