F’dor are fictional beings in fantasy novel series The Symphony of Ages by Elizabeth Haydon. In the series, F'dor are demonic spirits born of dark fire in the Before-Time, hunted by the Dhracians, with an ultimate goal of destroying the world. They are one of the First Born Races. As background to the story, few remain in the world, and most were sealed in the Vault of the Underworld. They have no corporeal form, and thus must take a host body. The potential host must be weaker than, or equal in strength to the spirit in order for the F'dor to subdue it (the exception to this is in cases of voluntary possession, where a strong host allows a weaker spirit in. A host cannot become a father or mother, as it would require the F'dor to share of its life force to create a new life, and by nature they are far too greedy to do that.
They are inherently evil and desire above all else to release their fellow F'dor from the Vault of the Underworld and burn the entire world to ashes.
There are two "generations" or pantheons of F'dor; the older and the younger. The older were the first ones born, from the primeval fires off the earth. These are considered to be more evil, as they actively chose the dark, evil fire instead of the pure, bright, elemental fire. The younger pantheon were born after this choice and thus know nothing other than the black fire.
In the first age, some of the F'dor stole one of the six eggs laid by the primeval wyrm, modified it and hid it inside the Earth. as the wyrm grew, it fed on the earth, and is now almost 1/6 of the mass of the world. all F'dor know the sleeping wyrm's name, and will try to become powerful enough to call to it, awakening the "Sleeping Child". If that happens, the earth will be destroyed, and the F'dor will have succeeded.