Smaug

Smaug is the dragon that made the Lonely Mountain his home. He was born in the first age, and is one of the few dragons left in Middle-Earth. He is especially greedy and a bit of a fool. Because of years of laying on gold and jewels, his treasure formed into his skin, creating an inpenitrable armour. He only has one weak point, near his heart. Bard shoots Smaug in this spot and kills him, avenging the people that Smaug killed.