Alchemical Hydra

The Alchemical Hydra is the third fight of the rebuilt roster — a four-phase chemical

monstrosity fought solo in your own instance. Its trick: the hydra takes **only a

quarter damage** until you lure it over the right chemical vent, and standing over the

wrong vent makes it hit harder. Positioning wins this fight.

Getting there

Teleport portal → Bosses → Alchemical Hydra lands you on the dungeon floor just south of

the lab — walk north up the narrow passage and climb the rocks (or type ::hydra).

Climbing back out puts you on the same floor. You need 95 Slayer: the portal refuses the

trip and the hydra refuses the attack below it, as in OSRS. Dying inside is a safe death.

The rest of the Karuulm Slayer Dungeon is open too (portal → Slayer).

The four phases

The hydra changes form as its health drops, and each form has a weakness vent:

Until the hydra stands over its weakness vent (they spew on a cycle — you'll see the

feedback messages), your hits are quartered. Standing over any other vent

empowers it (up to +50% damage), and standing on a spewing vent yourself burns you

for up to 20. Lure carefully.

Attacks

• It alternates ranged and magic every three attacks (every single attack when enraged) — count and switch your overhead prayer.
• Every ninth attack is the phase's special:
• Poison pools splatter around your tile — step off the splash zone.
• Walking lightning — four bolts crawl toward you; keep moving, getting caught deals 20 and roots you.
• The fire phase — it returns to the centre, pins you for a moment, walls off the room's edges with fire and sends a tracking flame chasing your footsteps. Keep walking; standing still gets you clipped, and standing in fire burns fast.

Loot

Every kill drops hydra bones plus a solid coin/supply roll (dragon knives and

thrownaxes among them). The chase drops, all Collection Log entries:

Every kill rolls the drop table and counts toward ::kc. After a kill, a fresh hydra rises in the chamber —

chain away.

See also

• Vorkath and Zulrah — the roster's other rebuilt fights.
• Bosses overview — what's live and what's returning.