Mactep the Black - Dragon in Waiting (Ma-tep)

She is an ancient Black Dragon who believes that dragons, not the gods, should be worshipped, and that dragons and their kin should be masters of the world. She rules the Starless Mire, a nearly endless swamp of sunken ruins and lost secrets, perfect for a dragon that hordes forbidden lore above all else. Perpetually dismal, dreary and pestilent, the Mire is shunned to nearly all civilized races - but serves as a haven for reptiles, insects, fungi, and anyone who needs to slink away from the light of the sun. Lizardfolk, bullywugs, hags and worse make their lairs in the swamp. The hags Sabal demands tribute from, the better to fill the sunken caves of her worm-ridden lair with forbidden lore. The rest she regards as test subjects for her dark rituals.
The Cult of Mactep has followers throughout the known lands, although it is outlawed in many for its followers' revolutionary ideas. Whilst some welcome their alternative perspective, traditionalist believe them to be dangerous.
Most people believe that the cult is based on an idea, or even a myth, of a powerful dragon known as Mactep. Very few people realize that she exists.

“There is no treasure greater than a secret someone doesn’t want you to know.”