Spider-Man: Into the Spider-Verse's gender-swapped Doctor Octopus was originally going to be male, before Kathryn Hahn was cast in the role.

Spider-Man: Into the Spider-Verse villain Dr. Olivia Octavius a.k.a. Doctor Octopus may have been gender-swapped from the comics, but co-director Rodney Rothman says that the character was originally going to be male. Voiced by Kathryn Hahn, Doc Ock at first appears to simply be a dedicated scientist working for the Kingpin, but after Miles Morales and Peter Parker infiltrate the research facility where she works, she reveals herself to be a version of the mechanical-limbed mad scientist.

Directed by Rothman, Bob Persichetti, and Peter Ramsey, Spider-Man: Into the Spider-Verse is currently celebrating an Oscar win for Best Animated Feature Film. Praised by critics and fans alike for its unique and dynamic animation style and heartfelt story, Into the Spider-Verse follows young New Yorker Miles Morales as he is bitten by a radioactive spider, gains incredible abilities, and meets a host of Spider-People from alternate universes.

Related: Bob Persichetti, Peter Ramsey & Rodney Rothman Interview

Spider-Man: Into the Spider-Verse is now available on Digital HD, with the Blu-ray release coming in March, and one of the bonus features (h/t ComicBook) details the casting process for Doc Ock. In the feature, Rothman explains that "up to a year, a year and a half" before production concluded, they had been planning to feature the male Doc Ock as the villain. "Then we decided to make Doc Ock a woman," Rothman explains. "We were taking elements of the classic Spider-Man story and twisting them."

When Peter B. Parker, a visitor to Miles Morales' universe from another dimension, sees Doc Ock in her mech suit, he confirms that his own universe has its own version of the villain - presumably the Otto Octavius that fans are familiar with. The scene functions as a neat twist, since fans on the lookout for a male Doc Ock weren't expecting Olivia to reveal herself as the villain, and at first she comes across as simply a harmless (if a little over-enthusiastic) scientist. Hahn elaborates on this in the bonus feature:

"When you first meet Doc Ock you think it's just this nerdy kind of mild mannered, brilliant but socially awkward scientist. Like all great villains, not everything isn't always what it seems. There are some nods to the classic character, such as her glasses and trench coat. But this Doc Ock does really kind of look like me."

The male version of Doctor Octopus was memorably played by Alfred Molina in Sam Raimi's Spider-Man 2, so even casual fans were aware of the character going into Spider-Man: Into the Spider-Verse - though certainly not expecting him to show up as a woman. It's possible that Hahn will reprise her role as Olivia Octavius, since Spider-Man: Into the Spider-Verse is getting both a sequel and a spin-off - the former focusing on the relationship between Miles Morales and Gwen Stacy, and the latter an all-female team-up movie believed to be centered around Gwen Stacy. The spin-off in particular certainly sounds like an opportunity for Doc Ock to return with a vengeance.

More: Sony's Three Spider-Man Movie Universes Explained

Source: ComicBook