Cave Horrors are a mid-level Slayer monster and the only source of the Black Mask in OSRS — the core component of the Slayer Helmet. They’re located in Mos Le’Harmless, an island requiring a specific quest to access. Once you’re set up, Cave Horrors are a straightforward Slayer task that rewards patience with one of the most valuable Slayer drops in the game.
How to Get to Cave Horrors Old School RuneScape Key Takeaways:
- Cave horrors live inside Mos Le’Harmless Cave, with its main entrance on the island’s southern beach.
- Complete Cabin Fever and reach 58 Slayer before hunting them.
- Bring a light source unless you have lit the Fire of Eternal Light near the cave entrance.
- Wear a witchwood icon to protect yourself against the cave horrors’ damaging scream.
- The Trouble Brewing minigame teleport offers another route to the island after meeting its requirements.
- The black mask has a 1/512 drop rate.
4.9Where to Get to Cave Horrors in OSRS
Cave Horrors are found inside the cave on the south side of Mos Le’Harmless. Reaching the island requires completing Cabin Fever, which grants access to the island’s port.
Travel options for Cave Horrors in OSRS:
- Trouble Brewing minigame teleport: Complete Cabin Fever and reach 40 Cooking. Use the available teleport to Trouble Brewing, then travel south towards the main cave entrance.
- Ectophial and Bill Teach: Teleport to Port Phasmatys, then speak to Bill Teach aboard his ship. Sail to Mos Le’Harmless and head east towards the cave.
- Mos Le’Harmless teleport scroll: Teleport near the settlement’s northern gate, then travel to the southern beach entrance.
- Charter ship: Sail to Mos Le’Harmless after completing Cabin Fever, then follow the same route from town.
ℹ️ Wear a witchwood icon when fighting at close range. Without it, a cave horror’s special scream deals 10% of your total Hitpoints. Buy the icon from a Slayer master; it does not protect your Prayer points.
Cave Horror Combat and Slayer Tips
Cave Horrors are level 80 with 55 Hitpoints. They use melee attacks exclusively and have a moderate max hit of around 8–10. At 70+ Defence, most players tank them without prayer.
| Stat | Value |
|---|---|
| Slayer Level Required | 58 |
| Combat Level | 80 |
| Hitpoints | 55 |
| Max Hit | ~10 |
| Weakness | Crush |
Tips for efficient Cave Horror tasks:
- Use Guthan’s set or high-healing food if on a longer trip — their damage is low, but volume adds up
- Cannon placement works inside the Cave Horror area — significantly speeds up tasks
- The cave is multi-combat in sections; cannon coverage hits multiple enemies simultaneously
- Bring Witchwood Icon — the Prayer drain without it matters over longer tasks
The Black Mask Drop
The Black Mask drops at approximately 1/512 from Cave Horrors. Combined into the Slayer Helmet (via Malevolent Masquerade obtained for 400 Slayer points), it gives you 16.67% Attack and Strength boost against all monsters on the player’s current Slayer task. If you want to get to Cave Horrors without grinding Cabin Fever’s prerequisites first, our OSRS Quest services can handle the quest chain.
The Black Mask (i) imbued version (via Nightmare Zone) boosts Ranged and Magic damage on-task too — making the Slayer Helmet one of the most versatile helmets in the game for all combat styles during Slayer.
OSRS Cave Horrors FAQ
Below are the most common questions about reaching and farming Cave Horrors in OSRS.
What Quest Is Required for Cave Horrors?
Cabin Fever is required to access Mos Le’Harmless. It requires Pirate’s Treasure and Rum Deal as prerequisites. The full chain takes roughly 1–2 hours and grants access to one of the best Slayer task monsters in the mid-game.
Is the Black Mask Worth Farming at Cave Horrors?
The Black Mask is essential for the Slayer Helmet, which is best-in-slot for Slayer tasks. At 1/512, you might get it quickly or spend 2,000+ kills dry. Most players complete Cave Horror tasks during normal Slayer progression and eventually receive the mask naturally. Dedicated farming is viable for accounts that specifically need it.
Can You Use a Cannon at Cave Horrors?
Yes — Dwarf Multicannon works inside the Cave Horror area. Cannon dramatically speeds up tasks in the multi-combat sections. Bring cannonballs and place the cannon in a central spot for maximum coverage.
Do You Need the Witchwood Icon Every Visit?
Yes, every single visit. The Prayer drain effect is active any time a Cave Horror can reach you without the icon present. The drain rate is fast enough to empty your Prayer in minutes during active combat. The icon is cheap (900 GP) and lasts indefinitely — just keep it equipped.
How Many Cave Horror Kills for a Black Mask?
At 1/512 drop rate, the statistical average is 512 kills per mask. Many players receive it earlier; dry streaks beyond 1,500 kills aren’t unheard of. Since Cave Horror tasks are assigned in batches of 80–130 by most Slayer masters, you may need multiple task assignments before the mask drops.
4.9Cave Horrors are one of those Slayer monsters that feel routine until the Black Mask drops — and when it does, it’s one of the most impactful single drops in mid-game OSRS.