Smaug is a dragon in J.R.R. Tolkien’s Middle-earth.
He is the principal antagonist of The Hobbit and occupies the Lonely Mountain after driving out the Dwarves of Erebor. Smaug guards the Dwarves’ treasure, including the Arkenstone, and is described as powerful, intelligent, vain, and capable of speech. Bilbo Baggins confronts him during the quest led by Thorin Oakenshield.
Smaug is not a Balrog, although both are dangerous beings associated with Tolkien’s ancient world. The Balrog encountered by the Fellowship is a different creature, a spirit of fire and shadow dwelling in Moria. Smaug’s death comes after Bilbo discovers a vulnerable area in his armor and Bard the Bowman uses the Black Arrow to kill him at Lake-town.