Once classified as Extinct in the Wild, the black-footed ferret (Mustela nigripes) is one of the world's rarest mammals and the only ferret native to North America. This slender animal has a yellowish coloured coat, pale underparts and a dark tail tip and black feet. The muzzle, throat and forehead are white and there is a black mask around the eyes. As with most members of the genus Mustela, the males are larger and much heavier than females. The legs are short and the large front paws are armed with claws for digging.