They are able to use 3rd and 4th level spells depending on age. They tend to know spells that deal with darkness and will shun the spells dealing with light or fire. This darkness not only blinds but drains the life energy of creatures caught within to a quarter of it's normal strength. Due to their nature and substance they can only be harmed by magical weapons. They are immune to life drains of all type and they can't be subdued or sold.
Shadow dragons appear as wormlike dragons of lighter and darker shadows.
The bat-like wings are semitransparent, as is most of the body. If someone is trying to spot a shadow dragon, the eyes, pools of feral gray opalesense, are the easiest to detect. Then, however, it is usually too late.