Derek is the leader of the D.C. Scavengers, a villainous group who have a brief run in the comics. They're an on-the-road band of survivors who'll do whatever necessary to stay alive, with no qualms about stealing, killing, and of course scavenging to get by. As the man in charge, Derek is the most ruthless of the lot. He has complete authority over the group, and basically looks out for himself first and then the others, such as when he pushed a fellow member into a hoard of walkers so the rest of them could get away. He's arrogant and over-confident, leading his group to the gates of Alexandria and demanding Rick lets him in, thinking he can command him and challenge his leadership. There's a possibility that the Wolves will be a beefed up version of the Scavengers, and if that's the case then Derek would be a great choice as the face and leader of them.