Throkmaw

Bane of the Northern Waste, Throkmaw the Black is the mightiest winged Dragon, save Smaug, in all the Grey Mountains. Like Smaug, he is the son of Ancalagon and inherited much of his father's strength. Fortunately for the Free Peoples of Rhovanion, though, Throkmaw never ventures south of the peaks. Instead, he confines himself to rare flights into the northern wastes, where he hunts Trolls and Lossoth. His lair is situated beneath the Shab Arch, in the northern foothills of the range, about 20 miles northeast of Scatha's home in Gondmaeglom.