After news broke of the casting of Hawkgirl in the upcoming Arrow/The Flash Spin-Off series, we also found out that another new character had been cast as well. Doctor Who alum Arthur Darvill has been cast as Rip Hunter. Who is Rip Hunter? Well, he's a time traveler who's looking to get back to his original timeline. He's the character that was described as "The Traveler" when we heard previously about three new characters we hadn't yet seen on live action television.