Bilbo Baggins’s sword in J.R.R. Tolkien’s Middle-earth stories is called Sting.
Bilbo finds the blade in a troll-hoard alongside two larger Elvish swords, Glamdring and Orcrist. Because Sting is short by the standards of Elves and Men, Bilbo uses it as a sword even though it resembles a large knife to a Hobbit. He gives it its name after discovering that the blade glows blue when Orcs are nearby.
Sting later passes to Frodo Baggins, who carries it during the quest to destroy the One Ring. Its light provides an important warning in dangerous places, including the tunnels beneath the Misty Mountains and the passage into Shelob’s lair.
Sting should not be confused with Glamdring, which belonged to Gandalf, or Orcrist, which was carried by Thorin Oakenshield. All three weapons were forged by Elves in Gondolin, but Sting is most closely associated with Bilbo and Frodo.