In J.R.R. Tolkien’s The Hobbit, the dragon guarding the treasure is Smaug.
Smaug occupies the Lonely Mountain, also called Erebor, after driving out the Dwarves who once ruled there. His enormous hoard includes gold, weapons, and the Arkenstone, a prized jewel associated with the royal line of Durin’s Folk.
Bilbo Baggins enters the mountain during Thorin Oakenshield’s quest to reclaim the Dwarves’ homeland. Bilbo discovers that Smaug has a vulnerable patch on his underside and later communicates this information to Bard, the archer of Lake-town. Bard uses a black arrow to kill the dragon.
Smaug is sometimes confused with Tolkien’s other dragons. Glaurung appears in The Silmarillion and The Children of Húrin, while Ancalagon the Black belongs to the First Age. Smaug is the principal dragon of The Hobbit and is one of Tolkien’s best-known villains.