The living corpse of a dragon desperately holding on to life.

A dragon desperately clinging on to the last bits of her life energy.
 
She was fatally injured when forces from the Shadow realm attacked through a rift in the Eldwood. However, using her last remaining power, she was able to clamp down on the tear between planes, and held it shut.
 
As years went by, her body started to decompose, and her strength weakened, slowly failing to the force of the rift.