Netherskull

Netherskull was a death tyrant in Undermountain in the early 1490s DR.

History
Many years before the Year of Three Ships Sailing, 1492 DR, a beholder from the Underdark went into Undermontain. There it settled inside the Obstacle Course level and turned itself into a death tyrant, renaming itself Netherskull. It fought Halaster Blackcloak but the Mad Mage prevailed. However, Halaster decided not to destroy Netherskull, instead turning it into a dungeon guardian. Netherskull became the lord of the Obstacle Course level permitting Halaster to install his new magical traps here. Around 1392 DR, the Netherskull battled the paladin Fidelio, but he returned as a ghost and fought Netherskull many times.

Activities
Netherskull resided in its sanctum, where it raised all its defeated foes as zombies in its service. Nearby was an immense chasm created by its disintegrate ray, which Halaster had flooded with lava.