Dennis O'Neil in the context of "Green Lantern"

Neal Adams (June 15, 1941 – April 28, 2022) was an American comic book artist. He was the co-founder of the graphic design studio Continuity Associates, and was a creators-rights advocate who helped secure a pension and recognition for Superman creators Jerry Siegel and Joe Shuster. During his career, Adams co-created the characters John Stewart, Man-Bat, and Ra's al Ghul for DC Comics.

After drawing the comic strip based on the television drama Ben Casey in the early 1960s, Adams was hired as a freelancer by DC Comics in 1967. Later that year, he became the artist for the superhero character Deadman in the science fiction comic book Strange Adventures. Adams and writer Dennis O'Neil collaborated on influential runs on Batman and Green Lantern/Green Arrow in the early 1970s. For Batman, the duo returned the Batman character to his gothic roots as a contrast to the Batman television series of the 1960s. During their Green Lantern/Green Arrow run, O'Neil and Adams introduced a mature, realistic tone through stories such as "Snowbirds Don't Fly", in which Green Arrow's ward Roy Harper is revealed to have become addicted to drugs. The duo created and introduced the Green Lantern character John Stewart in 1971.

John Stewart is one of the principal superheroes known as Green Lantern appearing in American comic books published by DC Comics. The character was created by Dennis O'Neil and Neal Adams, and first appeared in Green Lantern (Volume 2) #87 (December 1971/January 1972). Stewart's original design was based on actor Sidney Poitier and he was one of the first African-American superheroes to appear in DC Comics.

Today John Stewart is one of the most popular and high-profile black characters in American comic books. Although a starring character in Green Lantern comics since the 1970s, he had a relatively low profile in mainstream popular culture until his adaptation for the 2000s animated series Justice League and Justice League Unlimited, voiced by Phil LaMarr. This led to an increase in the character's profile in comics, including a starring role in Justice League comics, and a massive expansion in the character's availability in DC Comics toys and merchandise. Wayne T. Carr was cast as John Stewart in the DC Extended Universe (DCEU) director's cut Zack Snyder's Justice League (2021) but his role was ultimately cut from the film. Aaron Pierre will portray the character in the DC Universe, beginning with the TV series Lanterns (2026).

Ra's al Ghul is a supervillain appearing in American comic books published by DC Comics, commonly as an adversary of the superhero Batman. Created by editor Julius Schwartz, writer Dennis O'Neil, and artist Neal Adams, the character first appeared in Batman #232's "Daughter of the Demon" (June 1971).

Most notable as the leader of the League of Assassins, Ra's al Ghul's name in Arabic translates to "Head of the Ghoul". He is the son of Sensei; the father of Talia al Ghul, Ali al Ghul, Nyssa al Ghul, Dusan al Ghul and Arkady Duvall; and the maternal grandfather of Damian Wayne, who is the biological son of Bruce Wayne/Batman and Talia. Other versions include other grandchildren such as Athanasia al Ghul (Injustice timeline), Hafid al Ghul (Damian's clone), Tallant Wayne (Brotherhood of the Bat timeline), and by last the siblings: Saif al Ghul, Taj al Ghul and Janan al Ghul (in the Earth al Ghul timeline). Stories featuring Ra's al Ghul often involve the Lazarus Pits, which restore life to the dying. The Lazarus Pits have considerably prolonged Ra's' life, making him particularly dangerous, as he has honed his combat skills for centuries. Though primarily an enemy of Batman, Ra's has also come into conflict with Superman and other heroes in the DC Universe.

Arkham Asylum (/ˈɑːrkəm/) is a fictional psychiatric hospital appearing in American comic books published by DC Comics, commonly in stories featuring Batman. It first appeared in Batman #258 (October 1974), written by Dennis O'Neil with art by Irv Novick. Located in Gotham City, the asylum houses patients who are criminally insane, as well as select prisoners with unusual medical requirements that are beyond a conventional prison's ability to accommodate. Its high-profile patients are often members of Batman's rogues gallery.

"A Death in the Family" is a 1988 storyline in the American comic book Batman, published by DC Comics. It was written by Jim Starlin and penciled by Jim Aparo, with cover art by Mike Mignola. Serialized in Batman #426–429 from August to November 1988, "A Death in the Family" is considered one of the most important Batman stories for featuring the death of his sidekick Robin at the hands of his archenemy, the Joker.

Jason Todd, the second character to assume the Robin persona, was introduced in 1983 to replace Dick Grayson, who was unavailable for use at the time. Jason became unpopular among readers after 1986, as writers began to characterize him as rebellious and impulsive, and Starlin advocated killing him off. Editor Dennis O'Neil was considering having Jason revamped or written out of Batman when he recalled a 1982 Saturday Night Live sketch in which Eddie Murphy encouraged viewers to call the show if they wanted him to boil a lobster on air. Inspired to orchestrate a similar stunt, DC set up a 900 number voting system to allow fans to decide Jason's fate.