Grimgnaw was a dwarven monk and member of the Monks of the Long Death, an evil monastic order that worshiped the very essence of death, which was personified as the "Silent Lord," and sought to bring as many living beings to death as possible.
He was from Clan Battlehammer but left Mithral Hall to pursue initiation into the Order of the Long Death. Akin to the cult, Grimgnaw had a deep, morbid fascination with death and dying and detested undead, as he believed undeath to be a means of escaping a natural death.
Later, Grimgnaw was encountered by Drogan Droganson's pupil in Cania. It was said that after the Hero of Neverwinter defeated Morag, Grimgnaw had mysteriously vanished (and, due to his presence in Cania, had apparently died in an unknown circumstance). Grimgnaw said that as Mephistopheles had abandoned Cania, it was necessary for it to have a new ruler, and proclaimed himself this ruler. He was accompanied by several companions, including Maugrim and Balpheron (a lich, which was ironic as Grimnaw was reputed to despise undead in any form), as well as a minotaur named Koth Uth Kalm (which had been killed by Lord Nasher Alagondar to avenge his murdered wife and child) - all of whom supported his claim to leadership of Cania. Believing that the hero posed a threat to his rule, Grimgnaw and his companions attacked them, forcing the hero to defeat them.