True Dragons in every sense of the word, most of the Great Wyrms were wiped out during the War of the Dragons well before the age of man and even before the arrival of the Elves into Eletreus and today, only 2 are known to still live. One, and perhaps the greatest of them all, Qaynyr, Champion of the Skies, dominates an area the size of Escia to the North of the Elven Kingdoms and was instrumental in the battles of the Cataclysmic Wars. And the other, the sleeping Dragon of Lhasa, Tianlong the Gentle.
While scholars postulate that there must be more, if there are more their location is unknown – and it is postulated that they are likely hibernating in a state of suspended animation like Tianlong the Gentle of Lhasa, and are able to sleep for literally thousands of years without sustenance (though woe betide anyone stupid enough to wake one from their slumber – for their automatic response to being disturbed is to quickly defeat any potential threat and return to sleep as quickly as possible)..
Great Wyrms have almost demi-god like powers, and are arch mages in their own right, capable of casting powerful over-tier spells by sheer force of will. They are beyond the intelligence of humans and can think on multiple levels and run hundreds of scenarios through their minds in but a second, making them almost impossible to outwit.
Physically, they are impervious to all but the most powerful magical weapons, and spells cast at them are usually reflected straight back to the caster from the magic inherent in their shining scales.
They can be any color, and any disposition – historically some were evil, some good, and some rather indifferent, and their coloration has no bearing on their outlook or intent.
All Great Wryms are able to fly by magical means, using their wings to change direction and increase their speed – and all can also breathe fire several times a day with such heat that it will melt steel. Their teeth and claws are essentially indestructible and razor sharp, even the slightest pinch from a Great Wyrm will penetrate all but the most powerful of magical armor – and a single swipe of their powerful, muscular tail is enough to topple the ramparts of even the sturdiest built fortification.