Weasel

Any one of various species of small carnivores belonging to the genus Putorius, as the ermine and ferret. They have a slender, elongated body, and are noted for the quickness of their movements and for their bloodthirsty habit in destroying poultry, rats, etc. The ermine and some other species are brown in summer, and turn white in winter; others are brown at all seasons.

small carnivorous mammal with short legs and elongated body and neck