The Toy Fox Terrier is a small terrier

Terrier

A terrier is a dog of any one of many breeds or landraces of terrier type, which are typically small, wiry, very active and fearless dogs. Terrier breeds vary greatly in size from just a couple of pounds to over 70 pounds and are usually categorized by size or function...

 breed

Breed

A breed is a group of domestic animals or plants with a homogeneous appearance, behavior, and other characteristics that distinguish it from other animals or plants of the same species. Despite the centrality of the idea of "breeds" to animal husbandry, there is no scientifically accepted...

 of dog

Dog

The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...

, directly descended from the larger Fox Terrier

Fox Terrier

Fox Terrier refers primarily to two different breeds of the terrier dog type: the Smooth Fox Terrier and the Wire Fox Terrier. Both of these breeds originated in the 19th century from a handful of dogs who are descended from earlier varieties of British terriers, and are related to other modern...

 but considered a separate breed.
Toy Fox Terriers are small dogs with a muscular and athletic appearance. Notable characteristic traits include a short glossy and predominantly white coat, coupled with a predominantly solid head, and a short, high-set tail. The breed has been deemed elegant and graceful with V-shaped ears and large eyes.