Corpse archers can be found in the eigth room of the Lumbridge Catacombs Dungeon which can only be entered after completing The Blood Pact quest. They were created by Dragith Nurn, a now undead necromancer, during his experiments with local stolen corpses. This is one of the monsters that drop Mask part 3, which can be used with the 4 other parts to create the Mask of Dragith Nurn. These are ideal monsters for low level melee players to train on as they have fairly good drops for those who want to earn money without risk.