Errtu was a balor, the second most powerful class of the true tanar’ri demons, after the demon lords. He was twelve feet tall, covered in red scales, had a large pair of batlike wings and a tail, and and had a horned, ape-like head with a dog-like muzzle. When he was in the throes of lust for power, he drooled an acidic saliva. His voice was gravelly, guttural, and harsh
Errtu once worked for the group of liches that created the artifact named Crenshinibon. When it was brought to “life,” Errtu was cast back to the Abyss. He originally thought Crenshinibon was destroyed in the same blast.2
After he learned that Crenshinabon had not actually been destroyed, Errtu devoted his existence to finding Crenshinibon again. His search for Crenshinabon led him into several altercations with the drow ranger Drizzt Do’Urden, who sought to keep the artifact out of Errtu’s hands. The first time, when Errtu was serving as Akar Kessel’s general in 1351 DR, Drizzt summoned Errtu, meaning to pose as a drow scout and inquire about Crenshinibon. When Errtu discovered Drizzt’s ivory unicorn pendant, he attacked the drow, surrounding himself with flames and using his whip to catch Drizzt and pull him into the flames. Upon contact with Drizzt, the flames were extinguished due to the magic of the as-yet unnamed scimitar Icingdeath. In a confused moment for both of them, Drizzt slashed Errtu with Icingdeath—causing the balor real pain and the blade’s magic even froze the tissues at the edge of the wound. Errtu and Drizzt were both shocked, having never even heard of a weapon with that effect, but Drizzt recovered first and stabbed the balor in the stomach. The scimitar’s magic won out, destroying Errtu’s material body and banishing him for a hundred years. As his body dissolved, Errtu reminded Drizzt of their long lifespans and promised revenge.4
In 1358 DR, after Drizzt’s companion Wulfgar was “killed” by a yochlol summoned by Vierna Do’Urden, the evil goddess Lolth gifted the barbarian to Errtu as a bargaining chip in exchange for his guardianship of Menzoberranzan during the Time of Troubles.5 Errtu tortured Wulfgar for six years.6
Wulfgar was freed in 1364 DR during Errtu’s second altercation with Drizzt. The balor had gained the artifact Crenshinibon and used it to build a stronghold in the Sea of Moving Ice, a body of water west of Icewind Dale and dotted with icebergs. Despite his dislike of cold, Errtu chose the place because of its natural barriers. He opened a gate to the Abyss and let innumerable lesser fiends through, as well as more powerful demons. Drizzt and his friends managed to fight their way through, and confronted Errtu in an ice cave. This time, Errtu had space to fly, and repeatedly teleported around the room, using his flames to melt nearby ice and fill the floor with water—in which he would periodically thrust his lightning-bladed sword to shock the companions. Drizzt and his friends would have died, if Wulfgar had not been inadvertently freed by a younger barbarian via the hammer Aegis-fang and joined the fight. Together, the companions managed to bring Errtu out of the air, where Drizzt struck with Icingdeath and banished him for the second time.