Direwolves - The World of Ice and Fire Glossary | OpenFiction
Direwolves
Creature
A species of wolf far larger and more intelligent than their common cousins, once found throughout Westeros but now confined to the lands beyond the Wall. A direwolf can grow as large as a pony and is one of the most fearsome predators in the North. The direwolf is the sigil of House Stark, and their appearance south of the Wall after centuries of absence is considered a portent.