OSRS Phantom Muspah Boss Guide

Following the events of Secrets of the North, the residual energy of the Strange Creature manifests as the Phantom Muspah, a challenging repeatable solo boss found deep within the Ghorrock Dungeon. Defeating the Muspah requires mastering its form changes, special attacks, and unique shield phase to claim its valuable rewards, including the components for the Venator Bow.

This guide provides a detailed breakdown of the Phantom Muspah's mechanics, phases, strategic approaches, and loot table.

Location & Access

  • Requirement: Completion of Secrets of the North.
  • Location: Ghorrock Dungeon (underneath Weiss). Access the lair via the crevice in the south-west section.
  • Fastest Travel:
    • Ring of Shadows teleport (requires DT2 completion and Frozen Tablet).
    • Icy Basalt teleport (or Weiss POH portal), then through the fence gap into the Salt Mine, then down into the dungeon.
    • Larry's Boat from Rellekka (Fairy Ring DKS).

Fight Overview & Mechanics

The Phantom Muspah (750 HP) is a dynamic fight involving phase changes, prayer switching, and dodging AoE attacks.

  • Form Switching: Alternates between Ranged (Green) and Melee (Brown/Spiky) forms.
    • Switches after taking ~100 damage in Ranged form or ~80 damage in Melee form. (Thrall damage doesn't count towards threshold).
    • Transformation spawns spikes around the arena, including one under you. Dodge immediately to avoid damage (~14) and healing the Muspah.
  • Freeze Resistance: Has 33% freeze resistance (ice spells last 66% of normal duration).
  • Special Attacks: Triggers at 75% (~637 HP) and 50% (~425 HP) health. The first special depends on the starting form; the second is the unused one.
    • Lightning Clouds (If Ranged form @ 75%): Muspah teleports rapidly, leaving moving lightning clouds. Stand on specific safe tiles (check external guides/tile markers) to avoid damage (~20).
    • Homing Spikes (If Melee form @ 75%): Slams ground, summons 2-4 spikes that slowly follow you for ~20s. Block them by standing behind hardened spikes on the ground.
  • Shielded Phase (Triggers below 127 HP):
    • Muspah teleports centre, shockwave (hide behind a spike or take ~80 damage).
    • Gains a prayer shield (75 HP) and activates Soul Split (heals for 50% of damage dealt).
    • Attacks like Ranged form but hits harder/more accurately.
    • Drain the shield using Smite prayer and/or Enchanted Sapphire Bolts (e) (highly effective).
    • After shield breaks, returns to Ranged form, spawns many spikes frequently until killed.

Form-Specific Tactics

Ranged Form (Green)

  • Weakness: Ranged.
  • Attacks:
    • Ranged Projectiles (Green): Default attack. Use Protect from Missiles. Max hit ~61.
    • Magic Attack (Charged Purple Orb): Occasional special. Hits up to 72 and applies Corruption (drains 18 Prayer over 18s). Switch to Protect from Magic IMMEDIATELY upon seeing the charge animation. Blocking fully prevents damage and Corruption. (Ward of Arceuus can prevent/cure Corruption).

Melee Form (Brown/Spiky)

  • Weakness: Magic.
  • Attacks:
    • Melee: Damage increases significantly the longer Muspah stays still next to you. Max hit ~34 (higher if stationary). Use Protect from Melee.
  • Tactics:
    • Freeze/Bind: Use Ice spells (Barrage/Blitz) or binds to keep distance. Remember freeze resistance.
    • Kiting: Run around the arena (an octagon pattern works well due to its size) while attacking with Magic.
    • Step-Back Method (Advanced): Stand in melee range, pray Melee. Attack Muspah. On the 3rd tick after your attack animation, click one tile away. Muspah attempts to melee as you move, hitting a 0 through prayer. Attack again as you step back. Repeat. Requires precise timing (5-tick cycle).

Shielded Phase Strategy

  1. Shockwave: As Muspah teleports centre (below 127 HP), immediately run behind an existing spike on the arena floor.
  2. Activate Smite: Turn on Smite prayer.
  3. Weapon Swap (Optional but Recommended): Switch to a Crossbow with Enchanted Sapphire Bolts (e).
  4. Attack & Pray: Continue attacking. Prioritize praying correctly against its Ranged/Magic attacks. Flick Smite on between Muspah's attacks if possible to conserve prayer, but prioritize protection prayers. Sapphire bolt procs will rapidly deplete the shield.
  5. Post-Shield: Once the shield breaks, it reverts to Ranged form and spawns many spikes. Finish it off quickly.

Shield Skip (Speedrunning/Advanced)

Highly luck-dependent, but possible to bypass the shield phase:

  • Requires dealing lethal damage within the 5-tick window between Muspah teleporting centre and applying the shield.
  • Stand close (1-2 tiles) to the centre spot as it teleports.
  • Spam-click attack immediately. Requires 2-3 high hits within those 5 ticks.
  • If successful, Muspah reappears with 1 HP instead of shielding.
  • Hybrid (Recommended): Bring both strong Ranged gear (Twisted Bow > Bowfa/Crystal > Armadyl Crossbow) and Magic gear (Shadow > Trident/Sanguinesti Staff). Use Ranged vs Ranged form, Magic vs Melee form. Requires more switches but generally faster kills.
  • Ranged Only: Viable, especially with Twisted Bow or Bowfa/Crystal. Kite the Melee phase while using Ranged. Slower Melee phase but fewer switches.
  • Magic Only: Generally slowest, only recommended with Tumeken's Shadow. Still benefits from a Ranged swap for Shield Phase (Sapphire Bolts).
  • Shield Phase: Crossbow + Enchanted Sapphire Bolts (e) are highly effective.
  • Spellbook: Arceuus (Thralls, Corruption spells, Ward of Arceuus, Death Charge) is generally best. Ancients (Ice Spells) useful for freezing Melee form if kiting is difficult.

Loot Table Highlights

  • Unique:
    • Venator Shard (1/100): Replaces all other loot for that kill. Used to create the Venator Bow. Can be broken down for 500 Ancient Essence.
    • Ancient Essence (Common): Used to charge Venator Bow/Saturated Heart, create Ancient Blessings. Drops in various quantities. Average ~760 per kill (excluding shard breakdown/caches).
    • Frozen Cache (1/25): Contains Ancient Essence.
    • Ancient Icon (1/50): Cosmetic item.
  • Secondary: Muspah drops 2 standard loot rolls OR 1 roll of supplies (Food + Potions) OR 1 Venator Shard.
  • Standard Loot: Includes runes (Law, Soul, Death, Smoke, Chaos, Fire), bolts (unf), noted resources (ores, glass, essence), food (Manta Rays), seeds (Tree/Herb), and some rune/dragon equipment.
  • Tertiary: Muphin (Pet, 1/2500), Clue Scrolls (Hard/Elite), Charged Ice (cosmetic pet transmog, guaranteed < 3:00 kill).

Average Kill Value: ~149k GP (excluding Venator Shard), ~293k GP (including Venator Shard value averaged out).

Conclusion

The Phantom Muspah is a well-designed solo boss that rewards mechanical skill and adaptation. Learning to handle its form switches, special attacks, and the crucial shield phase is key to efficient kills. Whether you're farming for the potent Venator Bow or simply seeking a challenging and profitable PvM encounter, the Phantom Muspah offers a compelling fight.

Need the stats or gear to take on the Muspah effectively? Check out our OSRS Skilling Services to train Ranged, Magic, and Defence, or Buy OSRS Gold to fund top-tier equipment like a Twisted Bow or Tumeken's Shadow! Explore our other Varlamore and Desert Treasure II guides for more endgame content.