Shadow dragons were evil true dragons that were either native to the Shadowfell, or transformed by years spent there.
Physically seeming insubstantial, shadow dragons had dark and translucent scales which helped them camouflage into the darkness around them. Shadow dragons were often mistaken for black dragons, but their horns pointed backwards. A long fringe of spines emerged from the back of a dragon's neck and its powerful tail featured a swimming fin.
A dragon egg could be identified as that of a shadow dragon by the purple tinge seen when held in front of an intense white light, though it shared this trait with deep dragon and amethyst dragon eggs.