Karen Gillan’s Nebula has been one of the coolest characters in the “Guardians of the Galaxy” franchise, with one of the driest, dead-pan deliveries of anyone in the MCU.

Gillan voices Nebula in a cagey way to make her seem as if she's hiding behind an icy facade. It turns out the actor has actually been doing an impression of two Hollywood legends.

When Gillan auditioned for Nebula, director James Gunn gave her a small word of advice, specifically instructing her on how to use her voice, to help her get the part.

Gillan told Good Morning America, “[Gunn] was like, ‘Do an impression of Marilyn Monroe and Clint Eastwood, because they're the same voice!’ And I was like, ‘Are they?’”

She added, “I listened to them and I was like, ‘Oh, they are!’ It's [...] that under-the-breath, American, husky voice. And I was like, ‘Oh!’ And that informed my whole character.”

Hearing it now, Nebula's voice does have a lot in common with Eastwood's trademark gruff, although her quips and verbal jabs don't exactly sound as sultry as Monroe's.