Tauriel
In The Desolation of Smaug, the hobbit Bilbo Baggins, and thirteen dwarves, are traveling to Lonely Mountain, and pass through the black forest of Mirkwood, where they are captured by giant spiders. The spiders are then attacked by the Wood Elves, led by Legolas and Tauriel. Tauriel saves Kíli by killing a spider that was attacking him, but the Elves take the dwarves as prisoners for trespassing on their land. During the dwarves' imprisonment, Tauriel forms a bond with Kíli. It is later mentioned that Tauriel is a talented warrior and for this reason, was made leader of the Mirkwood border guards. Legolas, the son of Mirkwood's Elven king Thranduil, is shown to be attracted to her, and she used to be attracted to him too, but because she is a lowly Silvan Elf, she does not believe herself worthy of him, and similarly, Thranduil does not consider her to be a proper match for his son.