Editing Eberron (section)

===Age of Dragons===
Basically, in the dawn of time, there were three great progenitor dragons: Siberys (good and/or celestial), Eberron (neutral and/or natural), and Khyber (evil and/or fiendish).  They either created or discovered the Prophecy, which is a cosmic force that seems to equate to destiny and fate.  The dragons fought over the Prophecy, which shattered both it and the world.  Siberys was broken into a thousand pieces in orbit around the world, Khyber was bound into the depths of the Underdark, and Eberron merged with the physical world to heal it.  In the process of this, each of the dragons basically materialized as crystalline fragments that are harvested and used to empower certain magic items and effects.

From their godlike positions in the cosmos, they also create living beings.  Siberys creates the dragon races, which includes the couatls.  Eberron creates most of the bulk of the other beings - beasts, humanoids, etc.  Khyber creates fiends, most notably the rakshasas.