"The Inhabitant of the Lake": This entity is said to live in a lake in the Severn Valley region of England. It is not known whether Glaaki is somehow tied to the lake or if it simply chooses to be there.
Glaaki can influence the minds of humans, but this power has a limited range. Generally, it can only influence the unwilling if they live in the region next to the lake for a length of time. This influence often takes the form of dreams.
Glaaki has a round body with no discernable limbs. Its back is covered by long, sharp spines. On the front is a large mouth, above which are three yellow eyes.
Glaaki has a small cult following, though that may be the wrong term for it. It can create what are called Servants of Glaaki, which are humans who have been forced into a zombie-like state. This happens by Glaaki driving one of his spikes through the victim's chest and injecting a fluid, which keeps the victim from true death. Some have said that this impalement is the initiation to the cult of Glaaki, so it is not clear if he has any truly human worshippers.
Glaaki is also associated with the book The Revelations of Glaaki.