Undead Dragon

Even though the mighty dragons can become 100 years and older, their lives also come to an end at some point. Just like some humans, also some dragons simply cannot let go though. Some of them acquire dark secrets in their long lives. Others forge dark pacts with necromancers and demons to rise again after death.
It is said that the first Undead Dragons were created by the malicious bonelords who are known to meddle with undeath and necromancy. Created as a weapon in some ancient war, the first Undead Dragons proved to be so powerful that they could not be controlled by their masters. They broke free of the bonelords' subterranean bone fencings and wreaked havoc on their own. The escaped Undead Dragons served as role models for other dragons who longed for this seeming immortality. Even though only a few dragons walked the shadow path that ultimately led to the embrace of unlife, those who did began to transform into even more powerful and threatening beings which finally developed to Undead Dragons. More similar to the lich than the usual undead, they have kept more of their former personality and knowledge than undeads of other races are able to. Their new powers make easily up for the loss of some of their dragon skills.