Garn Mathers is a level 37 named mob located on an island at Dreadmurk Shore in Dustwallow Marsh[63, 29]. He is a member of the Defias Brotherhood. Mathers may be the highest level "directly affliated" Defias mob in the game.
He is the current leader of the Defias in Dustwallow Marsh. He and his gang reside on a large island just off the coast to the northeast of Sentry Point near a fairly large shipwreck. Killing him will retrieve any important documents containing information as to why the Defias are in the area.
He may be related to Jason Mathers.