Carmine Infantino in the context of "Batgirl"

Eobard Thawne, also known as the Reverse-Flash or Professor Zoom, is a supervillain appearing in American comic books published by DC Comics. Created by John Broome and Carmine Infantino, the character first appeared in The Flash #139 (September 1963) and has since endured as the archenemy of Barry Allen / The Flash. Eobard Thawne, as introduced by name in The Flash #153, is the first and most well-known character to assume the Reverse-Flash mantle, and is additionally a descendant of Malcolm Thawne and ancestor of Bart Allen, Thaddeus Thawne and Owen Mercer.

In his post-Crisis on Infinite Earths comic book appearances, Professor Eobard Thawne is depicted as a scientist from the 25th century who originally idolized the Flash. He replicated the accident that gave the Flash his powers, but was driven insane and became obsessed with ruining the Flash's life upon learning that he was destined to become his greatest enemy–the Reverse-Flash. Fueled by jealousy and hatred, Thawne travels throughout time to torment and destroy the Flash's life. He has been established as one of the fastest speedsters in the DC Universe. Thawne has frequently died, but has made multiple returns through resurrections and time travel.

Barbara Joan Gordon is a superheroine appearing in American comic books published by DC Comics, commonly in association with the superhero Batman. The character was created by television producer William Dozier, editor Julius Schwartz, writer Gardner Fox, and artist Carmine Infantino. Dozier, the producer of the 1960s Batman television series, requested Schwartz to call for a new female counterpart to the superhero Batman that could be introduced into publication and the third season of the show simultaneously. The character subsequently made her first comic-book appearance as Batgirl in Detective Comics #359, titled "The Million Dollar Debut of Batgirl!" in January 1967, by Fox and Infantino, allowing her to be introduced into the television series, portrayed by actress Yvonne Craig, in the season 3 premiere "Enter Batgirl, Exit Penguin", in September that same year.

Barbara Gordon is the daughter of Gotham City police commissioner James Gordon, the sister of serial killer James Gordon Jr. and is initially employed as head of the Gotham City Public Library. Although the character appeared in various DC Comics publications, she was prominently featured in Batman Family which debuted in 1975, partnered with the original Robin, Dick Grayson, whom she has a history of working closely and being romantically involved with. In 1988, following the editorial retirement of the character's Batgirl persona in Batgirl Special #1, the graphic novel Batman: The Killing Joke depicts the Joker shooting her through the spinal cord in her civilian identity, resulting in paraplegia. In subsequent stories, the character was reestablished as a technical advisor, computer expert and information broker known as Oracle. Becoming a valuable asset providing intelligence and computer hacking services to assist other superheroes, she makes her first appearance as Oracle in Suicide Squad #23 (1989) and later became a featured lead of the Birds of Prey series. In 2011, as part of DC Comics The New 52 relaunch, Barbara recovered from her paralysis following a surgical procedure and returned as Batgirl. Barbara has since featured in the eponymous Batgirl monthly title as well as Birds of Prey and other Batman books. Following the events of Joker War, Barbara returned to her Oracle role while recovering from an injury, and continues to operate as both Batgirl and Oracle after the 2021 Infinite Frontier event.

Poison Ivy is a character appearing in American comic books published by DC Comics. Created by writer Robert Kanigher, Sheldon Moldoff and artist Carmine Infantino, she debuted in Batman #181 (June 1966) and has become one of the superhero Batman's most enduring enemies belonging to the collective of adversaries that make up his rogues gallery.

In her comic book appearances, Poison Ivy is depicted as a doctor of botany-turned-misanthropic ecoterrorist in Gotham City named Pamela Lillian Isley, PhD (/ˈaɪzli/ EYEZ-lee) with the ability to control all plant life. Empowered by an elemental force known as the "Green", Ivy attempts to protect the sanctity and supremacy of nature at all costs by lashing out against humanity, which brings her into conflict with Batman. While usually portrayed as a supervillain, Ivy has also been an antiheroine at times as well as the primary love interest of Harley Quinn as of The New 52 and DC Rebirth relaunches. A one-piece costume adorned with leaves and vines serves as Poison Ivy's visual motif.