I have this weird Teen Wolf/Arrow headcanon that Roy Harper is actually Jackson Whittemore, who, after being changed at the butt end of s2, ran off to Starling City to "start over." He leaves Lydia, Danny and his parents a vague letter, took all the money he could get (birth parents' inheritance included), boarded a plane and took off to a random place a dart picked on the map for him, and changed his name and background (Danny may or may not have helped a bit). 'Course, with his new abilities, and a bit of a new perspective in life, he decides to lay a little low, so he gets a cheap place in a not-so-good neighborhood and at least tries to get by without drawing too much attention.