Great Old Rat

The Great Old Rat, also known as the Lord of the World Below and the Under-Father, is the supreme lord of rats, and brooks no other gods before him.
The Great Old Rat is infinitely patient, an insidious evil that has gnawed on the edges of reality since the earliest times. Undying and eternally scheming, this cunning patron patiently awaits the day of the Great Ascendancy, when his children will swarm across the face of the world, devouring it from within.