Daoloth

Daoloth is an Outer God from the expanded Cthulhu-mythos.

Overview
Daoloth is described as a being that dwells in dimensions beyond the three known to humans.

He is worshipped by those who seek knowledge, similiar to Yog-Sothoth. Due to his eldritch appearance, he must be summoned in the dark. The entity must be held in magical containment if summoned, as the Outer God's physical form always continues to expand, possibly at an infinite rate. Those who summon Daoloth are often transported to other worlds/plains of existence, which usually lead to the perishing of said person.

Trivia

 * Daoloth is a later addition in the myhtos, added by Ramsey Campbell.