Warning: The following contains SPOILERS for Batwoman, season 1, episode 13, “Drink Me.”

The latest episode of Batwoman, “Drink Me,” made use of a character concept that had once been pitched for Batman: The Animated Series but was rejected as being too dark for a children’s cartoon. The same idea later found its way into the Batwoman comics, but with a reinvention of the same obscure Batman villain that almost appeared in the cartoon: Nocturna.

First appearing in Detective Comics #529, the first Nocturna was Natalia Knight; an astronomer at Gotham City Observatory, who was left with a severe sensitivity to sunlight following an accident with an experimental laser that bleached her skin. After her adoptive father died, Natalia discovered that he was a criminal and teamed with his biological son to continue his activities so that they could continue to enjoy the lavish lifestyle to which they’d grown accustomed. The Nocturna name was later adopted by a woman named Natalia Mitternacht; a former astronomer and piano player with pheromone control powers, who first appeared in Robin #100. Yet another Nocturna (also named Natalia Mitternacht) appeared in Issue #9 of the New 52 Detective Comics run in 2012. This Nocturna was a vampire, a thief, and a black widow killer with a string of dead husbands, who attempted to seduce Kate Kane and bring her under her control.

Nocturna would have been reimagined as a vampire long before it happened in the comics had the creators behind Batman: The Animated Series gotten their way. Paul Dini had pitched a story based around the idea of Bruce Wayne being turned into a vampire. This was to be facilitated by a female vampire called Nocturna, who would try and fail to seduce Batman into becoming a true creature of the night. The story, which shared some elements of the 1991 Batman graphic novel Red Rain, was rejected by Fox Kids, who had a strict rule against depicting anything that suggested blood-draining or vampirism. The idea reportedly never went past the pitch phase and Bruce Timm drawing a design for the vampire Nocturna.

Batwoman made the idea of a vampiric Nocturna into a reality, mixing elements of the comics while presenting its own unique spin in the episode “Drink Me.” The Arrowverse version of Nocturna was a serial killer who drained her victims of blood and left their bodies tied up in artistic displays for the police to find. Speculation ran wild as to Nocturna being a true vampire and it seemed like a real possibility after Batwoman found herself injected with some kind of narcotic after being bitten by Nocturna during their first battle. This sedative later proved to be ordinary Ketamine and Nocturna’s fangs were later shown to be implants. Nocturna was ultimately exposed as Natalia Knight; a porphyria patient who had turned to murder to retrieve the blood she needed to treat her condition, after the death of her caretaker.

While the Arrowverse didn’t present a true vampire with its version of Nocturna, it can’t be denied that its take on the character was deeply disturbing. It also would never have been approved for Batman: The Animated Series. It remains to be seen, however, if this new Nocturna will escape Arkham Asylum and do battle with Batwoman another night.

More: Arrowverse Already Broke Its Post-Crisis Multiverse Rules