Rat Terrier

Dog

The Rat Terrier is an American dog breed with a rich and varied background as an all-around farm dog and hunting companion. Traditionally more of a type than a breed, they share much ancestry with the tough little mixed-breed dogs known as feists. Several private associations have maintained Rat Terrier registries for some decades, but more recently there have been movements to obtain breed recognition by the major canine organizations.

http://en.wikipedia.org/wiki/Rat_Terrier