A yak is a kind of cow from "The Cat in the Hat Knows a Lot About That".
A yak is hairy to keep warm where it comes from, the Himalayas. It can be 11 feet long (excluding the tail) and 1,300 pounds.
Wild yaks live in herds from 10 to 30 animals. Groups of more than fifty are rare. Domesticated yaks are used for carrying things and even a sport called yak racing.
Gallery of Real Yaks