Nightwing is a fictional superhero appearing in American comic books published by DC Comics. The character has appeared in various incarnations, with the Nightwing persona most prominently being adopted by Batman's partner Dick Grayson when he outgrows his identity as Batman's sidekick Robin.Nightwing remains strongly associated with Batman, but the title and concept have origins in classic Superman stories. The original Nightwing in DC continuity was an identity assumed by alien superhero Superman when stranded on the Kryptonian city of Kandor with his pal Jimmy Olsen. Drawing inspiration from Batman and Robin, the two protect Kandor as the superheroes Nightwing and Flamebird. Following a continuity reboot in 1985, Nightwing was originally a vigilante from Krypton whose legend inspires Dick Grayson's choice of name when he sheds the name Robin.Other stories set among the Batman family of characters have seen acquaintances and friends of Dick Grayson briefly assume the title, including his fellow Robin alumnus Jason Todd. Meanwhile, Superman stories have seen Superman's niece Power Girl and adopted son Chris Kent take up the name for brief turns as Nightwing. Various other characters have taken the name in stories set outside DC's main continuity as well, and at times the role has been unoccupied, such as when Dick Grayson operated as Batman and after faking his death.Nightwing the comic book, which focuses on Grayson, has long been a top-selling DC book. In 2013, Nightwing placed 5th on IGN's Top 25 Heroes of DC Comics and Grayson as Nightwing was ranked the #1 Sexiest Male Character in Comics by ComicsAlliance in 2013.