The Hydra's claw is a rare drop from the Alchemical Hydra, and its only use is to turn a Zamorakian hasta into a Dragon hunter lance. The lance is a one-handed spear with a draconic bonus, so the claw is what a player buys or farms for that weapon. The conversion is permanent.
Grand Exchange price history
What the Hydra's claw is used for
The claw has one product: the Dragon hunter lance. Use the claw on a Zamorakian hasta, read the warning, and confirm. Nothing else is needed to combine them once you have the hasta, and the process takes no skill level.
The lance is a one-handed spear that attacks every 4 ticks, with +85 stab, +65 slash, +65 crush and +70 strength. Its draconic effect gives 20% more accuracy and damage against dragons and similar creatures, and it works multiplicatively with Void and the Slayer helm (i). To wield it you need 78 Attack and the Barbarian Training sections for Firemaking (not the pyre step), Fishing and Smithing.
How to get the Hydra's claw
The claw comes from one boss, or from other players.
Because the Alchemical Hydra can only be killed on a hydra Slayer task, the claw cannot be farmed off-task.
Is the Hydra's claw worth it?
It is worth it only if you want the lance. Against dragons the lance's bonus is large, and it is the melee answer to the Dragon hunter crossbow and Dragon hunter wand, which cover ranged and magic.
Compare the claw's price with what you would pay for a lance, and remember the hasta is a second cost. Use the DPS calculator to test the lance against your own gear before you commit.
Hydra's claw FAQ
What is the Hydra's claw used for?
Where does the Hydra's claw drop?
Can you reverse the Dragon hunter lance?
What do you need to make the lance?
What does the Dragon hunter lance do?
Is the Hydra's claw tradeable?
Is the Dragon hunter lance better than the Dragon hunter crossbow?
Update history
Source: OSRS Wiki — Hydra's claw (Changes).
