In the beginning there was everything, but it was enclosed in the shell of nothingness. There was no one to warm the egg and hatch out all the worlds—just the endless black night, as hard and cold as diamonds.
And then, in a moment, something new awoke. There, on the boundary between the inside of the shell and the outside of the yolk, arose the one we call Io. He saw all things waiting to be born and knew that only from nothingness could that happen. So he became the nothingness, grew within it, and spread until he stretched to the ends of the night. And the everything within the egg stretched with him, until he became everything as well. He sent himself through every part of what would ever be, and when he was one with it as well as with nothingness, the Blending was accomplished.
Everything and nothing were blended in Io, and he began to turn. Slowly at first, and then more quickly, he spun out the sky, the stars, and the worlds. In his spinning, colors appeared along with gleaming streaks of metal, and they separated into two rings. Each ring spun off and became a great wyrm, Tiamat of the Many Colors and Bahamut the Metallic Lord, and then all the kinds of dragons. Later, other creatures appeared among the worlds, but dragons were the first and most beloved of Io. Yet, a small part of everything and nothing remained within Io, despite all he created.
Io still spins, but ever more slowly now. When he stops, the nothingness will encase him and form a new egg holding all the worlds and tomorrows to follow.
Source: Races of the Dragon Pg 66