Den Darga was the leader of the Lu'un Darga and an ancient enemy of Ra's al Ghul. According to Talia al Ghul, the Lu'un Darga were the original guardians of the Lazarus Pits who wanted to destroy all life on Earth to protect the Lazarus Heart. This was in contrast to Ra's al Ghul, who wanted to balance life on Earth, not destroy it.
During his Year of Blood training ritual, Damian Wayne was tasked with stealing artifacts sacred to the Lu'un Darga from dozens of locations around the world and bringing them to Al Ghul Island, which greatly reduced Den Darga's power. Some time after becoming Robin, Damian attempted to atone for his Year of Blood by returning the artifacts to their rightful places, not knowing that this would result in the return of the Lu'un Darga. This caused Den Darga to appear on Al Ghul Island, which he destroyed through summoning giant worms from the ground.
Den Darga was later revealed to have a son, Suren Darga.