Players can buy a witchwood icon from any Slayer Master and must wear it while fighting cave horrors in close combat. You can damage them without the icon, but the icon protects against the cave horrors' scream. Without the icon, the scream reduces stats and life points, similar to the effect of a banshee when fought without earmuffs or a Dust devil when fought without a Face mask. The Deflect Melee and Protect from Melee prayers will not block this damage.
The witchwood icon is not necessary when engaging in long range combat from a safe spot, so neck wear with better combat modifiers can be worn instead. It is recommended to carry an icon in inventory when using this tactic, in case close combat occurs by accident.
In contrast to most monsters, the cave horror has an irregular attack speed, which can shift in the middle of a battle. Time between attacks can be either 2.4 seconds or 3.0 seconds. This makes it somewhat difficult to utilise the prayer flashing tactic effectively. However, this is compensated by their comparatively low amount of life points.
The good thing about this cave is that there is a staircase in the north-eastern end, on the surface there is Edible seaweed that can heal 200 life points. If utilised correctly, you can stay here for quite a long time, farming clue scrolls (except you can only have one clue scroll at a time) or black masks.
Mos Le'Harmless Caves - in a cave on the southeast side of the island which can be accessed quickly through the Fairy ringD•I•P (requires Fairy Tale III). Players need a light source (such as Seer's headband 4 or a bullseye lantern) to operate in the cave. If a player goes in without a light source, bugs will rapidly bite them hitting 10-100 and can kill the player quickly depending on their number of life points. (Note: If using the fairy ring shortcut, you must first repair the bridges connecting the fairy ring island to the Mos le'Harmless mainland. This will require a total of 8 regular planks and 16 nails of any kind. Each bridge must be repaired from a different side, meaning you must fix it from the Mos le'Harmless side as well as the fairy ring island side if it is your first time using the shortcut).
Another way of getting there is by using the charter ship.