Black Heart is a gigantic four legged red scaled and black chested europeon looking dragon and is the loyal steed of Dread Wing. He looks just like his rider; vicious, cruel and evil, but above all, obeys his master's order.
He is able to drink lava and regurgitate it, giving him the ability to breath fire at his enemies. He is the only known dragon of this world to be capable of using a dragon breath along with Fury's cub.
Dread Wing seems to care more about Black Heart than anyone else. He doesn't hesitate to martyr Gangryn or knock his subordinates but the one time Black Heart will get sick in the episode 9 "Bugz", he will order immediately to find an antidote.