The terrier is a group of dogbreeds initially bred for hunting and killing vermin. While usually small, these dogs are brave and tough with a lively, energetic, and almost hyperactive personality. The largest breed in this family is the Airedale Terrier.

Most terrier breeds were developed in the British Isles. They were used to control rats, rabbits, and foxes both over and under the ground. Some larger terriers were also used to hunt badgers. In fact, the word terrier comes from the Middle French terrier, derived from the Latinterra, meaning earth. The Kerry Blue Terrier and Airedale, however, are particularly noted for tackling river rats and otters in deep water.