Winter Wolves are a magical variety of wolf which can be found in the wilderness south of Nashkel and on Ice Island. They are completely immune to cold damage and can breath ice at their enemies. Their DPS is high, but are otherwise not too difficult to kill on their own, even at low levels. Given their high experience value and Winter Wolf Pelt drops (which can be sold for 500 apiece at the Nashkel Store and 250 elsewhere), they're highly sought after.
The proprietor of the Nashkel Store is offering a good deal on winter wolf pelts.