Scatha

Scatha was one of the greatest Long-worms to live on Middle-earth.

History
Of his life little is known little is known before his appearance in the Third Age. Scatha's lair was in the southern slopes of the Grey Mountains from where he greatly troubled the Men and Dwarves residing there, terrorizing them and stealing their treasure. The Éothéod leader Fram son of Frumgar and ancestor of Eorl the Young slew the beast.

Origins
It is presumed that Scatha was one of the dragons that survived the War of Wrath and fled Northeast. Similar to Smaug, he seems motivated by greed rather than a desire to do evil and it appears that he was unnafilliated with either Dark Power.