Harry Potter and the Deathly Hallows
Affiliation: Death Eater (wannabe)
Greyback is just the baddest of the baddies. He's a super-evil werewolf who delights in violence, destruction and in his own cruelty – he's actually the werewolf who attacked both Lupin and Bill Weasley. Here, he's in the employ of Voldemort, but since he's not human, he's not granted full Death Eater status, and doesn't have the real mark of the elite, the Dark Mark.