Mummu

Mummu is the Babylonian spirit of Pure Chaos.

Historical
Mummu is a Mesopotamian deity; his name is derived from the Simerian "umun" which means "main body, bulk, life-giving force."

Conspiratorial
In The Illuminatus! Trilogy, The Justified Ancients of Mummu (JAMs) are a secret society that follows Mummu. While the official story was that Mummu had been killed in the war between the gods, the Jams claim Mummu still lives. As evidence, they point to all the chaos still around, and claim Mummu is actually alive and more powerful than the gods who supposedly killed him.