When Anne Hathaway got the part of Catwoman in Christopher Nolan’s The Dark Knight Rises, she famously watched cat videos on YouTube in order to get into character, but there’s one other key ingredient that informed her performance: the actress Hedy Lamarr, whom Batman creators Bob Kane and Bill Finger based the character on. “I know this sounds odd, but her breathing is extraordinary,” Hathaway told the Los Angeles Times. “She takes these long, deep, languid breaths and exhales slowly. There’s a shot of her in [the 1933 film] Ecstasy exhaling a cigarette and I took probably five breaths during her one exhale. So I started working on my breathing a lot.” Still, there’s one retro Catwoman bit that Hathaway was happy to leave behind. “When she made her first appearance [in the comics] she meets Bruce Wayne and says ‘Let go of me or I’ll claw your eyes out,’ and he says, ‘Careful, claws in or papa spank,’” Hathaway said. “So I’m glad we’ve come a long way since then.” Though imagine Christian Bale trying to say that line with a straight face!