Smaug guards the treasure beneath the Lonely Mountain in J.R.R. Tolkien’s The Hobbit.
Smaug is a powerful dragon who drove the dwarves of Erebor from their kingdom and claimed the mountain’s immense hoard. Thorin Oakenshield leads the expedition to reclaim it, accompanied by twelve other dwarves, Bilbo Baggins, and later the wizard Gandalf’s guidance.
Bilbo enters the mountain and speaks with Smaug, using riddling names and indirect clues rather than revealing his identity. During that encounter, Bilbo notices a bare patch in the dragon’s otherwise protected underside. He later tells the people of Lake-town about it, and Bard uses a black arrow to strike Smaug there.
Smaug’s death does not end the conflict. The treasure becomes the cause of a dispute among dwarves, Men, and elves, which leads to the Battle of the Five Armies. Smaug is sometimes confused with Glaurung or Ancalagon, but those dragons belong to earlier First Age stories in Tolkien’s legendarium.