Ghwyrn was an intelligent, awoken dire wolf that had lived among the cultists of Farhold for many years. He was large, observant, and had a weak spot for the unspoiled children of the small town.
When the party met Ghwyrn in Farhold, he immediately recognized Pierre as one of the kin, and trusted him with knowledge of alternative ways of entering Farhold, after having overheard the party's plans a short while earlier. Ghwyrn also revealed to Pierre that the keep had once been a dwarven stronghold that worked the "blood of the earth" into wondrous items, though these days, the keep had been repurposed to the designs of the Farwalkers.
When Balogun proceeded to find a way inside the Keep on his own, the alarms of the town were set off, and Ghwyrn were unable to cause a diversion to let the party enter Deephome, the tunnels under the town. Instead, he led them safely through the town defenses to the front gates of Farhold, while the party was invisible, after which they eventually found their way into the keep.