Smaug is a fictional character in The Hobbit by J. R. R. Tolkien. He is a dragon, and the main antagonist within the story.
One of the last great dragons of Middle-earth, Smaug rose to prominence by laying waste to the town of Dale and capturing the Lonely Mountain (Erebor) with all of its treasure. He was already centuries old at the time, this having happened over 200 years before the events of The Hobbit. The book recounts the tale of a party of dwarves (consisting of a few of the original residents of the Lonely Mountain and their descendants) and the titular hobbit to recapture the mountain and kill the dragon. In the book, he is sometimes called Smaug the Golden or Smaug the Magnificent.
Smaug was intimately familiar with every last item within his hoard, and instantly noticed the theft of a relatively inconsequential cup by Bilbo Baggins. According to Tolkien, his rage was the kind which "is only seen when rich folk that have more than they can enjoy lose something they have long had but never before used or wanted." This theft of a cup, Smaug's knowledge of every item in the hoard, and the dragon's ensuing rampage all echo the story of Beowulf, on which Tolkien was a noted expert and which he described as one of his "most valued sources" for The Hobbit. Among the items in Smaug's possession were the Arkenstone, and a number of mithril mail shirts, one of which was given as a gift to Bilbo by Thorin Oakenshield, the company's leader. In The Lord of the Rings, set years later, the shirt saved Bilbo's relative Frodo from injury multiple times.
As with most dragons, Smaug's underbelly was vulnerable, however he imbedded his belly with gems and gold, essentially giving himself an impenetrable armour. However, when Bilbo met him in his lair, he discovered a bare patch on his left breast. When Bilbo told his Dwarf companions about Smaug's weakness, he was overheard by the thrush that roosted by the mountain's secret door. The thrush in turn told Bard the Bowman of Esgaroth. When Smaug attacked the town, Bard shot his Black Arrow into Smaug's left breast, the armour's weak spot, killing him.
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