Sometimes wolfs lose hair and when they do they drop this, wolf fur.
Every wolf can lose fur so you can find some wolf fur in the open field.
You can use the wolf fur to make Wolf Armor, which is further described in it's own page.
The fastest and best way to get wolf fur is to get friends with alot of wolves and put them in a closed area
and every now and then walk trough it to get all the furs :)