13, real name unknown, is a dangerous and powerful young man who appears in Beacon Hills shortly before Peter V. Hale's escape from Eichen House. Apparently now in league with the mad werewolf, he acts as the muscle for Peters group and is far stronger than his human roots would show. Able to fend off werewolf and supernaturals bare handed, his strength and fighting skill is unparalleled, and nothing short of the Stepford Cuckoos or a realized Royal Breed would stand in his way.
Unlike his cohorts he seems specifically interested In Scott, and will abandon missions or openly defy Peter to engage the young alpha in combat. Why he does so is unknown, but despite his superior strength to Scott's, 13 has yet to finish the young man off completely.
Like his allies, who he really is is unknown, but he appeared around the same time Scott McCall's father, Rafael vanished, leading other to believe that 13 was responsible for his disappearance.