Nightwing
Nightwing is a fictional superhero appearing in American comic books published by DC Comics. The character has appeared in various incarnations, with the Nightwing identity most prominently being adopted by Dick Grayson when he moved on from his role as Batman's vigilante partner Robin.
Robin (character)
The character was rediscovered by a new generation of fans during the 1980s because of the success of "The New Teen Titans", in which he left Batman's shadow entirely to assume the identity of Nightwing. He aids Batman throughout the later storyline regarding the several conflicts with Jason Todd until he makes his final return as the "Red Hood". Grayson temporarily took over as Batman (while Wayne was traveling through time), using the aid of Damian Wayne, making his newish appearance as "Robin", to defeat and imprison Todd. With Bruce Wayne's return, Grayson went back to being Nightwing.