Nightwing
Although Nightwing is commonly associated with Batman, the title and concept have origins in classic Superman stories. The original Nightwing in DC Comics 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 the Crisis on Infinite Earths continuity reboot in 1985, Nightwing was re-imagined as a legendary vigilante from Krypton whose story inspires Dick Grayson's choice of name when he leaves behind his Robin identity.
Nightwing
In 2001's "" #111, Superman and Lois Lane travel to a version of Krypton later revealed to have been created by the villainous Brainiac 13 and based on Jor-El's favorite period in Kryptonian history. Labeled as criminals, Superman and Lois become fugitives, adopting the Nightwing and Flamebird identities to survive, just as had Superman and Olsen in "Superman" #158.