Two-headed trolls were never fully explained in Tolkien's works, as it is speculation as to whether or not they actually had two heads, or they were trolls that were directly controlled by Sauron, hence the idea of 'two' heads. Like other trolls, the two-headed trolls lived in the Ettenmoors since the destruction of Angband at the end of the First Age, however, they were believed to be more aggressive than other breeds of troll such as the Olog-hai.[citation needed]