The Bloodworm Helm is the necromantic crown of the famed lich Mannimarco, who magically constructed it out of trollbone. Although beautiful to behold, many find the artifact repulsive due to its morbid nature. The helm grants the wearer greater skill at Conjuration, as well as the ability to turn the undead, drain the essence of enemies, and summon a skeletal minion. If the wearer is undead, their attacks are also made more powerful.
By 3E 427 the helm had come into the possession of a Nord necromancer named Crazy Batou, who had established a lair in an ancestral tomb in the Molag Amur region of Vvardenfell. Batou was killed by the Nerevarine, who then sold the helm to Torasa Aram. Torasa put the helm on display in the Mournhold Museum of Artifacts. It was later obtained by the Mages Guild, and transported to the Arcane University in Cyrodiil for safekeeping.
In 3E 433, Mannimarco returned to the affairs of mortals and attempted to destroy the Mages Guild. The Council of Mages dissolved in the ensuing attacks on the guild, and Master-Wizard Irlav Jarol took the helm to the abandoned Fort Teleman in Blackwood with a group of researchers to study the artifact in an effort to better understand how Mannimarco could be stopped. The expedition went against the advice of Arch-Mage Hannibal Traven, who feared for the group's safety. Traven was proven correct when Irlav's experiments resulted in the summoning of many dangerous Daedra; Irlav himself was slain by a hostile Dremora. The Order of the Black Worm then launched an assault on Fort Teleman to recover the artifact for Mannimarco, but they were held at bay by the Daedra. A member of the Mages Guild was sent by Traven to recover the helm, and stumbled into the ongoing battle. The mage successfully infiltrated the ruins and took the helm from Irlav's corpse. It was then brought back to the University and returned to a secure place in the Arch-Mage's Tower.
Sometime in the Fourth Era, a necromancer was collecting items for his lair that ranged from trinkets to artifacts that fit the morbid and macabre. He had become fixated with obtaining the artifacts of Mannimarco; the Bloodworm Helm and the Staff of Worms. An apprentice was tasked with retrieving the former, to which they brought the Helm of Oreyn Bearclaw, confusing one skull helm for another. He recruited a new apprentice named Naara after this ordeal, who then attempted to slay him and take the artifacts he had found for her own ends. This would be her downfall, for the apprentice was trapped within the room which had been turned into a puzzle. Should Naara want to take the artifacts, she would have to earn them by using them to figure out the puzzle to be freed from the trap.
Circa 4E 201, the Last Dragonborn located a necromancer's lair at Gallows Hall and completed the puzzles set out by the place's former owner, thus earning the right to claim Mannimarco's artifacts and the lair itself.
- Tamrielic Lore — Yagrum Bagarn
- Helm of Oreyn Bearclaw
- Torasa Aram's dialogue in Tribunal
- Bloodworm Helm's abilities in Oblivion
- Bloodworm Helm's abilities in Morrowind
- Bloodworm Helm's abilities in Skyrim
- Events of Morrowind
- The Museum quest in Tribunal
- The Bloodworm Helm quest in Oblivion
- Dreams of the Dead quest in Skyrim