Cows are passive farm animals that are found on New Trismus (south of the village), at the farm on Lesser Aradoth, and on the Isle of the Drowned near the confectioner's center. There is a cow or two near Heather at (22856,26110) as well.
They can be harvested for Milk with a Bucket while living. When killed, they can be harvested for Meat with a Harvest Knife or Hides with a Tanning Blade.