Mace of the Crows is a Legendary mace in Diablo III. It was added in patch 2.4.1., though a bug prevented it from dropping until 2.4.2. It can only be used for Transmogrification. It drops from a rare Mysterious Barrel located in The Barracks Level 2. Easiest way to get this is to Waypoint to The Battlefields, Act III, heading north and on the left is entrance to either The Barracks Level 1 or Fortified Bunker. Since it is a Normal item, it can be traded among players.