Smaug is the dragon defeated by Bard in J.R.R. Tolkien’s The Hobbit.
Smaug occupies the Lonely Mountain after driving the dwarves of Erebor from their kingdom. He guards the mountain’s treasure and attacks Lake-town when he realizes that Bilbo Baggins and the dwarves have entered his domain. Bard, a descendant of the former kings of Dale, learns of Smaug’s vulnerable spot and kills him with a black arrow.
Smaug is sometimes confused with Tolkien’s other dragons, especially Glaurung and Ancalagon the Black, who belong to stories set in the earlier history of Middle-earth. Smaug’s death does not end the conflict over the treasure: his attack leads directly to the Battle of Five Armies, fought among dwarves, elves, humans, goblins, and great eagles.