Just as the title says; It's a Dragon, and it's "element" is deseases and decay... Wherever it stays or pass by, creatures and environments around it gets infected with some kind of disease, or decays and eventually dies... A kind of "Death Dragon" some might call it. I guess there could be some kind of magic or equipment that would withstand the effects of this Dragon. If he were to be captured and tamed by some evil, power-hungry being with resistance against it's aura and breath, many cities could easily fall into ruin... I surely hope that no such evil ever will arise! Original drawing from 2006.