Bilbo gives his sword the name Sting in J.R.R. Tolkien’s The Hobbit.
Bilbo finds the blade in a troll-hoard alongside two larger Elvish swords, Glamdring and Orcrist. Because it is much smaller than those weapons, it suits a hobbit particularly well. Bilbo names it Sting after using it against giant spiders in Mirkwood.
The sword has a distinctive magical property: its blade glows blue when Orcs or goblins are nearby. That feature makes it a practical warning device during Bilbo’s journey and later during Frodo’s travels. Frodo inherits Sting from Bilbo and carries it during the quest to destroy the One Ring.
Sting is sometimes confused with the great swords carried by Gandalf and Thorin. Glamdring belongs to Gandalf, while Orcrist becomes Thorin’s weapon. Andúril is a different sword entirely: Aragorn’s reforged blade in The Lord of the Rings.