The Mad God is a supernatural entity common to all the mythologies and religions of the North — where mythologies and religion are still valued.

While not a true god, he is a being of chaos and bloodshed, and is considered the most powerful, the most malevolent, and most absorbed in human affairs of any of the thayoi. He is considered the wellspring of warfare, oppression, and crime, and when the world has been at peace for too long, he will actively try to stir up rebellion and hostility to sow disorder.

Every now and then, he claims the soul of some human as his emissary in the world—his Scion—usually to confront Wake's Zealot.