Smaug was the dragon who lived beneath the Lonely Mountain in J.R.R. Tolkien’s The Hobbit. He had seized the mountain and its treasure from the Dwarves of Erebor before the story began.
Smaug’s attack drove King Thrór and many of his people into exile. Years later, Thorin Oakenshield organized an expedition to reclaim Erebor, bringing Bilbo Baggins as the company’s burglar. Gandalf arranged Bilbo’s involvement, believing that stealth and intelligence could help the Dwarves.
Bilbo enters Smaug’s chamber and discovers that the dragon has one vulnerable area: a bare patch in his jewel-like armor on the left side of his chest. Bilbo’s information reaches Lake-town, where Bard uses a black arrow to kill Smaug during the dragon’s attack.
Smaug is distinct from earlier dragons in Tolkien’s mythology, such as Glaurung and Ancalagon. Those creatures belong to the older legends associated with the First Age, while Smaug appears in the Third Age.