Nightwing

"I grew up in a circus. It's always been about catching people when they fall."

- Nightwing

Nightwing is a name that has been used by several fictional characters in the DC Comics Universe. It was conceived as a Kryptonian analogue to the character of Batman, with Nightwing's frequent partner Flamebird based on Robin. The Nightwing persona originates with a Kryptonian vigilante taking the name of the "Nightwing", a bird native to the planet Krypton.

History
Prior to DC's continuity-altering 1985 limited series, Crisis on Infinite Earths, the Nightwing identity was depicted as an invention of Superman's during a time when he and Jimmy Olsen act as vigilantes in the Kryptonian city of Kandor; Superman draws inspiration from his encounters with Batman and Robin.

Post-Crisis, the name is attributed to a historic Kryptonian crime-fighter; this hero serves as an inspiration for Dick Grayson when he sheds his Robin identity and assumes the name and a new costume. Grayson was featured in an ongoing Nightwing series between 1996 and 2009. The most recent character to assume the name Nightwing is Superman's adoptive son Chris Kent, who - like the original Nightwing - is also Kryptonian.

Batman Reborn
Following the disappearance of Bruce Wayne at the end of Final Crisis, Dick Grayson inherits the mantle of Batman and takes Damian Wayne as his Robin. Their dynamic is inversely similar to Bruce and Dick's when he was Robin. After Bruce Wayne returns, he allows Dick Grayson to continue being Batman while he travels the world recruiting vigilantes for Batman Inc..

New 52
Dick Grayson resumes the Nightwing mantle shortly before the New 52 begins and is once again independent of Batman.

During the Forever Evil events, Nightwing is captured by the Crime Syndicate and has his identity revealed to the world. After the Crime Syndicate is defeated, Batman has Dick retire the Nightwing identity under the pretense that he was dead so that he could become a secret agent.

Quote
"You never know if you can fly unless you take the risk of falling."

- Nightwing

"Enjoy your victory Grayson. Because it's going to be a long night. And happy ends are not going to be easy to come by. Let's see what else Gotham has in store."

- Nightwing

"Want to get Chinese later"

- Nightwing joking in Injustice

"On the other hand that way might be good to."

- Nightwing after hearing some screaming for help in Batman the animated series

"Good news. I found Penguin. He's right where I want him. Bats, I'm fine don't worry about me."

- Nightwing in Batman Arkham Knight after being captured by Penguin