First off I should say that I LOVE dragons. From being a little boy who knew every dinosaurs name, and fairy tales to now. Theres something extra fantastic about dragons! The above image is the first stage in a piece that I am presently working on. I shall post later versions of this piece as it is brought together.
Dragons for me have always had a magic of their own, not necessarily evil, but rarely good, more than animal but certainly not human. Being hard to define seems the hallmark of these creatures, and from this comes their greatest appeal.
In mythology, dragons come in many shapes and sizes. Bestial, animal-like dragons abound in legends, all great slithery or flapping monsters that kill with tooth and claw, and sometimes with fiery breath (though this is a more recent addition). They seem to be a catch-all "unknown terror" sort of creature, a sort of mish-mash of mans foes in the fierce world of nature.
Some folks claim that some of these sorts of "common" dragons were actually remnants of dinosaurs, knocking around corners of the wilderness. This is certainly a neat idea, and would help explain some of the uniformity of reptilian monster legends around the world. The kid in me would very much like it if there really were dinosaurs being battles by spear sword-wielding adventurers and that the Thunderbird was really a Pterosaur.
The greatest sorts of dragons from old stories were being possessed of great magical power. Some, such as the Babylonian Tiamat, and the Pelasgion serpent god Ophion were thought to be vital to the creation of the world in some way or another. Even Biblical beings such as the Saraphim (sometimes translated as "fiery flying serpents") and in the dread sense; Lucifer, (that "Old Dragon," etc) all had dragon-like references to their appearance, nature or power.
Many of the classic fantasy dragons hearken back to the dragon legends of the Anglo-Saxons, that viewed dragons as a sort-of remnant of fallen grandeur. Beings that represented the price of greed and the end of an age. This is a big reason why the Saxons did not occupy the fallen ruins of Roman Britain after its conquest, as that old Empire, having fallen to invasion was inherently cursed by fate. This is part of where the image of a dragon dwelling in a ruin sitting on a treasure it will never enjoy comes from.
Modern fantasy's dragons seem to run somewhere between the common bestial dragon and the god-like cosmic dragons of legend. Being both flesh and blood and magical power incarnate. Often greedy of gold or other treasures, and always possessed of some sort of magical power, whether it be actual spells, psychic powers, or an indomitableness that goes beyond flesh.
More on this later...