Julia Louis-Dreyfus got her teeth into the action in 'Thunderbolts'.

The 63-year-old star returns as the devious Valentina Allegra de Fontaine in the forthcoming Marvel Cinematic Universe (MCU) movie and explained that her alter ego isn't afraid to get her hands dirty in the film.

Julia told Entertainment Weekly at San Diego Comic-Con: "In this film, she certainly takes advantage of people we've come to think of as underdogs and uses that to her advantage.

"It was fun for me to play a hyper-manipulative person who is about four steps ahead of everyone in the piece, and that was cool. And I did my share of kicking ass."

Geraldine Viswanathan makes her MCU debut as de Fontaine's assistant Mel and described it as a "dream" to be working so closely with the 'Veep' star.

The Australian actress said: "I'm kind of her little right-hand man. And kind of going, 'Wait a minute? Who is this, and what's she doing?' So we're really paired up, which is a dream – it's Julia Louis-Dreyfus!"

'Thunderbolts' director Jake Schreier previously explained that his film will differ from other pictures in the MCU when it is released next year.

He told Screen Rant: "I can't say what it is, but I can say that there is something different. And I think that, again, when you look at something like 'Beef ' there's a specificity of character that then makes the whole thing feel more universal, because it comes from something so personal. And I think that something that was exciting about 'Thunderbolts' is it's not a sequel.

"It's a new story, and it's a set of characters that maybe we've met a little bit in the MCU before, but this is a very new take on who they are and what brings them together. Probably not what people are expecting from it, but I guess I can't really say more than that."