The revenant dark beast is a type of revenant. It is more dangerous than its combat level suggests; however, it's typically less dangerous than a player with the same combat level. Like all Revenants, it can deal large amounts of damage with melee, ranged, and magic.
Like all revenants, they can restore health quickly (in intervals of 1,515), cure themselves of poison and react quickly to a player's protection prayers/curses.
The Revenant dark beast hits up to 1,000, but only up to approximately 850 with melee. Revenant dark beasts do not require level 90 slayer to kill, but can be killed as part of a dark beast slayer assignment. They are also classified as ghosts, so they can be killed for part of a Ghost assignment.
The Forinthry Dungeon is a PVP-enabled area, meaning it is entirely possible for other players to attack you whilst fighting the revenants in the dungeon. Do not bring any equipment that you are not willing to lose. It is highly suggested that when fighting this creature, you bring good food and bring friends of different combat types to help you in case of player killers.