Killing the Alchemical Hydra
The Alchemical Hydra is a task-only Slayer boss killable after reaching 95 Slayer.
The Alchemical Hydra uses both the Ranged and Mage combat styles.

Drops:

Here are the drops that you can expect to receive from killing the boss, as well as their respective drop rates for a normal mode easy difficulty account:

Ikkle Hydra 1/3,000 (Pet)
Jar of Chemicals 1/1,142
Dragon Thrownaxe or Dragon Knife 1/173 for drop table or 1/347 individually
Hydra's Claw 1/571 (Component to create the Dragon Hunter Lance )
Hydra Tail or Hydra leather 1/146 for drop table or 1/292 individually (Hydra tail is a component of the bonecrusher necklace, while hydra leather creates the Ferocious Gloves.)
Alchemical Hydra Heads 1/146
The Hydra eye, heart, and fang drop at 1/102 for the drop table or 1/308 individually. (Creates Brimstone Ring )

Requirements:
  • 95 Slayer
  • As high range level as possible, but shoot for 90.
  • 44 Prayer minimum to use the Protect from Magic/Missiles Prayer.


Gear Setup:


The gear setup was taken from the OSRS wiki page, as it is accurate on BattleScape as well. I edited it a touch to be more accurate to BattleScape. Use Ruby bolts (e) to deal 100 damage on proc to the hydra until the end of the red phase/beginning of jad phase, then switch to bp. (bolt proc is no longer worth it when hydra is under 42% health).

The Fight:

Phase 1:

All the colours related to the Hydra in the room as well as on the Hydra itself relate to the combat triangle. In the combat triangle, ranged is represented by green, melee by red, and magic by blue. The hydra has an attack pattern of attacking three times with one combat style, and then switching to the other for three attacks, and so on. The ranged hydra attack is a single projectile, while the magic attack is two projectiles side by side. (Identical to killing regular hydras). After the first three attacks the Hydra will spit poisonous blobs onto the ground, causing 12 damage per tick if you stand on them. Simply step a tile or so away when the hydra spits.

In order to deal proper damage to the Alch Hydra you will have to lure it to the corresponding coloured pools of chemicals in the room, which is why we touched on the combat triangle colours earlier. In the first phase of the Hydra fight you will lead the green hydra to the red pool.

Phase 2:

In this phase you will be luring the blue hydra to the green chemical pool. During this phase the Hydra will spit out an electric ball into the center of the room, which will spawn columns of lightning that converge on the player. If you get hit by the lightning you will receive 20 damage, and be rooted to the spot for a few seconds. In order to avoid the lightning, move to the northern wall of the room, and quickly move west while attacking the hydra.

Phase 3:

In this phase you will be luring the red Hydra to the blue chemical pool. In this phase the Hydra will take a few steps away from you and create a massive wall of fire on either side of you. Then, a trail of fire will begin to follow you. If you are hit by any of the fire you will immediately receive 20 damage, and then 5 damage every tick for 5 ticks. To avoid the fire damage, simply turn off run and walk while attacking the boss.

Final Phase:

The final phase of the hydra battle has no weakness, and you do not need to lure it anywhere. This is a Jad-like phase of the boss, similar to the final phase of Zulrah rotations. The hydra will attack you with the opposite of the last attack style that it attacked you with in the red phase and then switch attack styles every attack. You will have to switch prayers on each hit. This phase also has the venom blob spitting mechanic from the first phase.

Good luck !

Additional Notes:

The Hydra can also be killed with melee, although it is not as effective as ranged. Below is the gear setup for melee.