The Elros who appears in Peter Jackson's The Hobbit movie trilogy is a Wood-elf, the keeper of the keys of the Elvenking's prison cells. The character does appear in J.R.R. Tolkien's novel, The Hobbit, but is not named in the book.In Tolkien's legendarium of Middle-earth, Elros was the name of the twin brother of Elrond Half-elven. However, where Elrond chose to live as an immortal Elf, Elros chose to live as a mortal Man. Tolkien's Elros was the first ruler of the island kingdom of Numenor.