Richard John "Dick" Grayson was once Batman's first sidekick Robin and close friend, before going on to become Nightwing. Once he took up the mantle of Batman when Bruce was thought to be dead, but became Nightwing once again after the events of Flashpoint. After Forever Evil, Dick's identity was revealed to the world and Bruce convinced him to give up being Nightwing to become an agent of Spyral. He was created by artist Bob Kane, writer Bill Finger and by illustrator Jerry Robinson, he first appeared in Detective Comics #38 in April 1940.
The youngest in a family of acrobats known as the "Flying Graysons," Dick watched as a mafia boss killed his parents in order to extort money from the circus that employed them Bruce Wayne, secretly the vigilante Batman, took him in as his legal ward after witnessing their deaths, and eventually as his sidekick, Robin.
Throughout Dick's adolescence, Batman and Robin were inseparable. However, as Dick grew older and spent more time as the leader of the Teen Titans, he decided to take on the identity of Nightwing to assert his independence. His Nightwing persona was created by writer Marv Wolfman and artist George Perez, and first appeared in Tales of the Teen Titans #44. As Nightwing, Dick led the Teen Titans and later the Outsiders. Following the events of the Zero Hour miniseries, he temporarily replaced Bruce Wayne as Batman, beginning in Robin #0 and extending throughout the Batman: Prodigal storyline. In an eponymous series, launched in 1996 and continuing until 2009, he becomes the protector of Bludhaven, Gotham's economically troubled neighboring city. Following the destruction of Bludhaven, at the command of Deathstroke the Terminator, or Slade in Robin's case, Nightwing relocated to New York.
In the Legacy of Chris Thorndyke, in the past, he was under Batman’s wing but they had a fallout and he became a Teen Titan, then got promoted to Nightwing, which according to Raven, he looks pretty cool and doesn’t look like a moving target and he still gets along with Bruce and his Adoptive Brothers and even mentored Damian Wayne and patrols Bludhaven also known as Gotham but with even worse Crime Rate, even that he is still leader of the Teen Titans, even that his hands are tied with Batman and the Justice League.
And he is reprised by Scott Menville as Robin then to Loren Lester as Nightwing in the English dub and Takashi Onozuka as Robin then to Daisuke Ono as Nightwing in the Japanese dub.