Smaug is a clever, gold-hoarding dragon -- who also plays the part of the main antagonist -- in J.R.R. Tolkien's classic, "The Hobbit." Smaug is outfitted with armor-like scales, large wings, fiery breath and a fierce demeanor. However, like most dragons, Smaug also has an Achilles heel: a chink in his armor right over his cold, dark dragon heart. This defect turns out to be a lifesaver (although not for the dragon) when Bilbo Baggins, unlikely hero, thief and main protagonist, steals a gold cup from Smaug's mountain cave and notices the dragon's tender spot. This knowledge later allows a local man named Bard the Bowman to save his village by shooting an arrow through Smaug's ticker. Not before Smaug could reduce most of Bard's village to charred embers, though. All in all, it was a pretty good revenge for a Scrooge of a dragon [source: Tolkien].