Smaug is the primary antagonist in J.R.R. Tolkien’s The Hobbit.
Smaug is a great dragon who occupies the Lonely Mountain after driving the Dwarves from their kingdom. He guards their treasure, including the Arkenstone, and has ruled the surrounding region through fear for many years.
Bilbo enters the mountain as part of Thorin Oakenshield’s company and speaks with Smaug. The dragon’s conversation reveals his intelligence, pride, and suspicion, while Bilbo’s riddling style helps him avoid immediate discovery. Smaug also identifies the Shire as Bilbo’s home after hearing enough about his visitor.
Smaug is eventually killed by Bard of Lake-town, who uses a black arrow and knowledge of a vulnerable place in the dragon’s armor. Gollum is important to Bilbo’s earlier journey, but he is not the main antagonist of The Hobbit.