GrWOLF Warg Wolf
Grey wolves are usually found together in large packs, and often with Wolves, but may also be with Werewolves, Imps and Grey Imps. They're only found in the first half of the game.
Don't underestimate these things, a weak party can be torn to shreads. I would suggest you run from the large packs until you have Fir2, Lit2, or Ice2 to take care of them.
Grey Wolves are called warg wolves in the Japanese version and FF Origins. Wargs come from J.R.R. Tolkien's The Hobbit and The Lord of the Rings. They are large, intelligent wolves that often serve as mounts for goblins (or orcs?). Wargs can also be found in Castlevania Symphony of the Night and WarCraft 2. Dungeons & Dragons calls them Worgs. You won't find wargs in later FF games, but for more wolfy fun, see the Wolf page.