Serpentstrike is Runesaga's version of the Blowpipe from OSRS. It doesn't hit very hard, but it hits fast, especially with the ranged perk Rapid Reload.
It is dropped from Gyarados, and you charge it with Magikarp scales.
If you choose to uncharge it you get all your scales back.
Players can dismantle a Serpentstrike(uncharged) to receive 20,000 Magikarp scales.