The Black Mask is a helmet item that boosts slayer task damage.
It can be obtained from killing cave horrors on the island of Mos Le'Harmless.
The Black Mask is highly sought after for its bonus damage for slayer along with being a required item to craft the slayer helmet.
Reaching the Island[]
- You must have completed the Priest in Peril quest to gain access to Morytania
- You must also have completed the Dragon Slayer quest to gain access to a ship that sails from Port Phasmatys to Mos Le'harmless
- Speak with the Captain, Bill Teach, on the docks of Port Phasmatys to travel to the island of Mos Le'harmless for 1,000gp
Killing Cave Horrors[]
Cave horrors are quite strong and use a combination of melee and magic to attack.
They require 58 slayer but do not need to be your active slayer task to kill them.
