In J.R.R. Tolkien’s The Hobbit, Smaug is a dragon.
Smaug is the powerful dragon who occupies the Lonely Mountain and guards the treasure of the Dwarven kingdom of Erebor. He drove the Dwarves from their home after attacking the mountain, forcing Thorin Oakenshield’s people into exile. Their attempt to reclaim Erebor is the central mission of The Hobbit.
Smaug is notable for his intelligence as well as his physical strength. He speaks fluently, enjoys riddles and manipulation, and identifies Bilbo as a possible thief when the hobbit enters the mountain. Smaug’s armored body has one vulnerable area, a missing scale on his underside. Bilbo discovers this weakness, and the information reaches Bard of Lake-town.
The dragon’s death is not caused by Bilbo directly. Bard uses the knowledge about Smaug’s unprotected spot to fire the Black Arrow and kill him. Smaug is therefore both the main monster and a major driver of the novel’s plot.