Onyx dragon

Onyx dragons are high-level Slayer monsters, released on 3 April 2017. They're part of the gemstone dragon group, and succeed dragonstone dragons yet precede hydrix dragons in strength. They require the player to have 98 Slayer in order to kill them.

Onyx dragons are located under the Shilo Village mining site, and require the completion of the Hard Karamja Tasks in order to access them in the gem rock cavern underneath. In order to pass the barrier to confront them, players are also required to sacrifice a number of uncut dragonstone, uncut onyx, or uncut hydrix gems - with each gem type allowing the player to kill a certain (currently unspecified) number of dragons within their respective chamber; up to a limit of storing 60,000 kills at a time. If the player is on a Slayer task for onyx dragons, however, they may enter the onyx dragon area without the need for charges, and, if the player has already donated gems for charges, the charges will not be consumed while on-task.