In most ways, the dire wolf (S. "Gaedraug"; Q. "Nairanarmo"; pl. "Nairanarmor") resembled its smaller cousin, the common timber wolf. Found all over northern Middle-earth, they were intelligent, social animals that lived in family groups or small packs (2-11 and 10-60 members, respectively). Dire wolves mated for life, settled disputes among themselves with non-fatal duels, and cooperated among themselves in hunting. However, unlike common wolves, they had little or no fear of the Free Peoples. They would hunt Men, Elves, or Dwarves like any other prey.
Dire wolves weighed up to one hundred and fifty pounds, reached running speeds of up to thirty miles per hour, and leaped up to six feet in the air with little effort. Possessed of tremendous nightvision, they were more nocturnal than their smaller kin.