Help with a registered name for dog?

My dog Ranger is a rescue, so we don't really need a registered name. But I may register him for performance competitions in the future. While I know we don't need a "registered" name and could just use a "call" name, sometimes it's fun to come up with a registered name. So, just for funsies, I was wondering if anyone had any brilliant ideas for a registered name that would logically have a call name of "Ranger."