As far as Hollywood is concerned, women in the world of espionage are all fetching femmes fatales, smooth operators who can manoeuvre through any social situation and switch between one glamorous disguise and another.
Melissa McCarthy - whose speciality is playing comically eccentric characters - is thus not the first name that comes to mind when envisioning a super spy.
But the actress is known for rewriting the rules when it comes to women on screen, and that is why the secret agent she plays in the new movie Spy is a socially awkward plain Jane who goes incognito as a frumpy cat lady.
While that may seem groundbreaking in the world of film, McCarthy says what she is really doing is portraying a real woman with real flaws.
Speaking to Life! in an exclusive interview in Los Angeles, the star of such films as The Heat (2013) and Bridesmaids (2011) explains why she gravitates towards such roles.
"I don't pick perfect women (to play) because I find it incredibly boring. I literally wouldn't know what to do if they never screwed up. Also, I don't know any people like that," says McCarthy, who was the crass and hilariously inappropriate sister-in-law in Bridesmaids, a role which earned her an Oscar nomination.
"I know people who try to pretend to be perfect, but you know they're a terrible mess, and I don't know how to play that. I feel like you'd just be sitting there and it'd be like a photo - it's not a movie and it's not a story."
She says flawed female characters are considered radical only because audiences are accustomed to seeing impossibly perfect women on screen.
"Everybody says I play such 'different' women, and I'm like no, I play the women you see every day, I play women I grew up with," says McCarthy.
"What's so strange is people think I'm doing something out of the norm just because I'm playing regular women. For so long we've been watching these perfect, flawless, never-say-anything-wrong women. They're charming, their wardrobes are amazing and we've started to think that's normal.
"I actually know some of the most beautiful actresses in the world and they're not like that - they're normal people," says McCarthy, who grew close to Oscar winner Sandra Bullock (Gravity, 2013) while filming the buddy comedy The Heat, where she played a foul-mouthed police officer.
For Spy, which opens in Singapore tomorrow, the performer teamed again with Paul Feig, who directed her in The Heat and Bridesmaid, two of her biggest successes to date.
Feig will also helm the upcoming remake of Ghostbusters with an all-female cast led by McCarthy and Bridesmaids' star Kristen Wiig.
Asked why their collaborations have been so fruitful, McCarthy, who got her start in improvisational sketch comedy, cites the director's willingness to let his actors experiment and fail.
"On set, he's absolutely collaborative. I improvise a lot and he's so wildly open to that. And if you say something and it tanks, it almost doesn't matter, everybody laughs and then we move on.
"He doesn't care at all, he wants it to be spontaneous and I kind of think that's when you get a little bit of magic."
In addition, Feig has little regard for typecasting, which is how McCarthy found herself playing the lead in Spy, with her co-stars Jude Law (Sherlock Holmes, 2009 to 2011) and Jason Statham (The Expendables, 2010 to 2014) pretty much playing the equivalent of Bond girls or eye candy in the film.
McCarthy says: "Somebody said, 'Did you realise that Jude Law and Jason Statham were your boy-toys on this movie?' And I was like, 'Oh my god, that's awesome!'"
McCarthy reveals that she and Feig also share the same "juvenile" sense of humour.
"It's not very high brow. Almost everything Paul does destroys me - I become like that idiot kid who can't stop laughing because his brother said something funny.'"
Another reason she wanted to take on Spy is that it sees her character Susan Cooper triumph after being chronically underestimated. That is something the actress can still relate to even though she is a big star - not all her work has been well-received, especially after many critics panned Tammy, the 2014 film she co-wrote with husband Ben Falcone.
A few have also made unkind remarks about her appearance and weight, which led to a recent confrontation between McCarthy and a movie reviewer she ran into at a film festival.
According to the actress, the critic, whom she did not name, had written that Falcone should never be allowed to direct his wife because he let her look so "homely" in Tammy, about a woman who goes on a road trip with her grandmother.
McCarthy - who has two daughters aged eight and five - pointed out the inherent sexism in the fact that a male performer playing a depressed character, like Tammy was, would never be attacked for looking unattractive.
And she thinks it is unfair for anyone, male or female, to be dismissed because of how they look.
"People across the board are constantly being underestimated. I think it happens in all walks of life. I've certainly felt that way," she says, adding that this is why she wanted to play an unassuming spy who slowly finds a way to shine.
"Susan had all that ability but just didn't have the confidence. And watching someone like that come out of her shell is really fun."
Spy opens in Singapore tomorrow.