The Nightwing persona originates with a Kryptonian vigilante taking the name of the "nightwing", a bird native to the planet Krypton. This hero serves as an inspiration for Dick Grayson when, as the leader of the Teen Titans, he retires as Robin and takes on his own superhero identity as Nightwing to assert his independence (others would fill in as Robin). He becomes the protector of Blüdhaven, Gotham's economically troubled neighboring city.