Smaug is the dragon who takes over the Lonely Mountain in J.R.R. Tolkien’s The Hobbit.
Smaug attacks Erebor, the kingdom and treasure-hoard of the Dwarves, and drives its people into exile. He later occupies the mountain and guards its wealth. Thorin Oakenshield’s company sets out to reclaim Erebor, and Bilbo Baggins enters the mountain to investigate the dragon’s lair and learn about a vulnerable patch in Smaug’s armor.
That weakness is reported to Bard the Bowman by the thrush that overhears Bilbo’s conversation with Smaug. Bard uses a black arrow to kill the dragon during Smaug’s attack on Lake-town. The dragon’s death changes the political balance around the mountain and helps trigger the Battle of the Five Armies.
Smaug is sometimes mixed up with Tolkien’s earlier First Age dragons, including Glaurung and Ancalagon. Those figures belong to different stories and eras. Smaug is the principal dragon of The Hobbit and is characterized by intelligence, pride, greed, and a talent for persuasive conversation.