Fenrir Greyback is a supporting antagonist in the Harry Potter franchise, serving as a supporting antagonist in both Harry Potter and the Half-Blood Prince and Harry Potter and the Deathly Hallows Part 1.
He is a ruthless and dangerous werewolf who serves under Lord Voldemort as a member of the high-ranking Death Eaters. During the Second Wizarding War, Greyback and a group of snatchers allied themselves with Lord Voldemort and his Death Eaters, planning to become a ruler in the new world Voldemort creates.