7 Hollywood stars who were unrecognisable in famous roles – how many can you name?

Zoe has been unrecognisable in many of her roles, using a motion-capture suit to help bring Neytiri to life in the Avatar franchise, but when it comes to the Guardians of the Galaxy movies, the Hollywood icon gets into the prosthetic chair.

With the help of two makeup artists, it takes Zoe over three hours to transform into Gamora. It's not just her skin that is transformed, but Zoe's cheeks and forehead are also resculpted with prosthetics, meaning many wouldn't recognise the star behind the camera.

Charlize won an Oscar for her portrayal of serial killer Aileen Wuornos in Monster, and the blonde beauty totally transformed her body to take on the role. Not only did she gain 13kg to play the serial killer, but she also altered her eyebrows and wore prosthetic dentures. To further the illusion, the star also had her skin airbrushed in order to look more weathered.

Speaking about her weight transformation, she previously stated: "I had about three months to gain weight. We never discussed it like, 'I'm gonna put on 30 pounds,' because I wasn't trying to look fat. It wasn't that hard. I just didn't say 'no' to Krispy Kreme doughnuts or anything that was full of cream. I also gave up exercising."

Whether it's as Sirius Black in the Harry Potter franchise or Jackson Lamb in Slow Horses, Gary Oldman is known for his luscious, long locks. But to play wartime Prime Minister Winston Churchill in Darkest Hour, all of this had to go.

The star was incredibly committed to the transformation, which earned him an Oscar, sitting completely still for four hours as the makeup was applied, and refusing to sleep in it, as not to ruin it. It wasn't just lace wigs to capture Churchill's thinning hairline that Gary needed for the role, as his neck was brought forward and his chin was lifted with prosthetics so that his entire face matched the former leader of the country.

Nicole's transformation into novelist Virginia Woolf in The Hours, which won her an Oscar, was so incredible that even her diehard fans didn't recognise the blonde star when the first trailers for the film dropped. Nicole even joked to the San Francisco Chronicle: "I did enjoy being anonymous. It was fun to be able to go out of my trailer and not have anyone know me."

It wasn't the brunette wigs that transformed Nicole away from her signature blonde locks that got people talking, but her prosthetic nose that took three hours to apply, and divided critics.

Noting the jaw-dropping transformation, A. O. Scott said for The New York Times: "Ms. Kidman's physical transformation into Virginia Woolf seemed so impressive – and was so extravagantly praised – in part because it seemed so unlikely, because she had not struck anyone, until then, as the kind of actress who could disappear so completely on screen."

Sydney really threw herself into her role as professional boxer Christy Martin when she starred in and produced the biopic about the iconic 90s sportswoman. The blonde bombshell completely transformed her slender figure by bulking up to play Christy, while also swapping her trademark blonde hair for brunette.

On her physical transformation, she told ABC: "You have to train every day. I was drinking protein shakes after protein shakes after protein shakes, having to plug my nose and just chug it. It's so gross. Weight training morning and night, boxing all day. So that's a physical and mental challenge on its own."

Hollywood legend Tom didn't have the largest role in the 2008 satirical comedy, but he still completely transformed his appearance to portray studio executive Les Grossman.

The Hollywood hunk ended up wearing a fat suit, bald cap, fake prosthetic hands and plenty of movie makeup to play the hated character. To top it off, the role was kept secret, so audiences were completely surprised when the movie landed in cinemas.