Mask of Gloom

The Mask of Gloom is a slayer mask won from Treasure Hunter. It is associated with the dark beast slayer monster. It gives two free teleports to the monster twice a day, as well as extra Slayer experience while on a Slayer task of this monster and double drops on every tenth kill. The extra experience and drops are lost when the mask reaches a certain kill count, at which point it can be transformed into a helm.