Lair of the Demogoblin

From publisher blurb:

Dungeon Depths 4: Lair of the Demogoblin is a stand-alone and generic fantasy RPG adventure complete with maps, room descriptions, NPCs, and general information for a GM to run it using any fantasy RPG game. The adventure is rules-agnostic, meaning it will require some customization by the GM with regards to NPC and creature stats.

A young goblin shaman named Errg wasn't powerful or respected in his tribe, but he had plans to change that. Instead of becoming a lich, however, something dark and dangerous merged with him and now it seeks to do as much damage to the living as possible...