breed of terrier known for its relatively long legs and good nature; coat is short, dense, and wiry and normally forms a black-and-tan saddle pattern; small ears are set high on the head and fold forward onto the brow; thick tail is docked to half its natural length and carried erect with a slight curve; eyes are large for a terrier and deep-set and very dark; adult stands 14–15 in. (36–38 cm) at shoulders and weighs 18–20 lbs (8–9 kg); is very curious and playful; loves swimming; good with children; originated in Welsh highlands in mid-1800s to hunt fox, badger, and otter; bred to have unusually long legs so it could keep up with a hunter on horseback,