Mugg was part of the initial group of goblins that ambushed Gundren Rockseeker, Sildar Hallwinter and the party on the Triboar Trail. The sole survivor of the fight with the party, Mugg agreed to guide the party to Cragmaw Hideout in return for his life, remaining outside to faithfully guard their wagon.
He requested that his only friend within the clan, Magg, be spared, if possible. He was last seen heading off into the forest when the party returned to their wagon.