In the Hall of the Phoenix King
Demigod of winter, blizzards, and plague.
Gnilash is an epic level encounter. However, often an Avatar of Gnilash may be summoned by a sufficiently high level wizard. This takes on the aspect of Gnilash, but it is not the demigod himself. This avatar is often used by Gnilash’s followers as a backup, or an assassin where subtlety is unneeded.
Gnilash, demon prince of winter and plague, is a powerful demon in the Abyss. He is powerful enough to warrant demigod status. He commands many many followers, and is often seen by cultists as a second form of Orcus. This is not true, of course. He is a prince in his own right.
Among those who fall under his sway are vermin and other plague-carriers (and for this reason, many of those affected by Lycanthropy turn to Gnilash). Because of his association with frost and the slow death of winter, many dark sorcerers and warlocks turn to him for their powers. He is said to hold many warlocks under his command and is the master of multitudes of liches and dracoliches.
He finds amusement in the slow death and decay brought on by winter’s chill, by diseases, and by plagues. The onset of plagues into many kingdoms, and the decaying ruling classes, are said to be his doing. He likes nothing more than to let winter remain, to fester and be unable to be washed clean by spring.
Gnilash is said to have a particular abhorrence to fey creatures, as they make their homes amongst the springtime feywild. He will go out of his way to destroy one if it makes itself known to him.
He appears as a gigantic, heavily-muscled humanoid with greenish-black skin and covered in frost. A ferocious rat’s face sits on his head, and monstrous claws bigger than elephants cover his hands. Frost drips from his teeth and cold energy radiates from his breath, slowing the reflexes of anyone who approaches.
Rats and other vermin swarm around Gnilash, dragging their victims to the ground and swarming over them until nothing is left but a gnawed skeleton. The demigod drives vermin into a frenzy, and they spread before him and behind him like a dark shadow. Those killed by Gnilash and his minions do not gain the solid solace of death. Instead, their souls are dragged screaming into the Nine Hells, there to suffer an eternal decay.