Cannibal

The Cannibal is a wild dragon residing on Dragonstone during the Dance of the Dragons. Named it for a self-evident reason, The Cannibal was one of three completely wild dragons dwelling on Dragonstone, the others being Sheepstealer and Grey Ghost. The Cannibal was a coal-black dragon with baleful green eyes and the only dragon who breathed green dragon fire. He was the largest of the wild dragons, and the oldest, his age being unknown to history.

Physically, you are the largest known and recorded dragon, even bigger than Balerion the Black Dread, and Vhaegar. You are so large that when you are still, you cover massive amounts of territory with your body, especially when you're in the sky and you can turn the sky black when you flap your wings for how big you cover the sky. Your dragon body is pure black scales, black as coal, and you have emerald green eyes.

The smallfolk of Dragonstone alleged that the Cannibal was on Dragonstone before the Targaryens fled the Doom, over a hundred years before Aegon's Conquest, making him the oldest dragon in the world during the Dance and possibly older even than Balerion. This claim is disputed by maesters, who find it unlikely that a dragon could be so long-lived, with Balerion having died of natural causes at the age of at least 208, several decades before the Dance.

The Cannibal earned his name for his hostility towards House Targaryen's dragons, whom he was known to attack and devour; he used to feed on carcasses of dead dragons, and descend upon the hatcheries of Dragonstone to gorge himself on newborn hatchlings and eggs. In fact, he is the only dragon known to regard his own species as a source of food.

The Cannibal mostly refrained from killing people, unless they disturbed him. He never accepted a rider. He laired at the back of Dragonmont. Prior to the Dance of the Dragons, a dozen would-be dragon tamers had made attempts to ride him and his lair was littered with their bones.

None of the dragon seeds were fool enough to disturb the Cannibal due to his reputation - and any who were did not return to tell the tale. Archmaester Gyldayn in his history of the civil war makes no mention of the Cannibal perishing during the Dance of the Dragons so presumably he survived.