The Kandarian Demon is the creator of the Deadites, though it's unknown if it was created by the Dark Ones or they got it to do their bidding. Sometime in the past, it was placed into a slumber by a spell within the Necronomicon. To summon the Kandarian Demon requires the reciting of passages in the Necronomicon. Known sightings of the Kandarian Demon include in medieval England (circa 1300 AD), the United States in Tennessee (1980s), and again in the United States in Michigan (early 21st century).
It is able to turn nearly anything into a Deadite, including plants, humans, and inanimate objects. When it comes to humans, it will focus on a specific target. Going so far as to chase the target, until it "infects" the victim. In its non-corporeal form the Kandarian Demon has the ability to apply physical force, and can fly long distances several feet over the ground.