Margot Robbie donned a stunning unicorn dress for the 'Suicide Squad' world premiere.

Margot Robbie

Margot Robbie

The 26-year-old actress - who portrays Harley Quinn in the highly-anticipated Warner Bros. and DC Comics anti-hero movie about a mercenary team of super villains - walked the black carpet at the Beacons Theatre in New York on Monday (01.08.16) in a sparkling Alexander McQueen gown emblazoned with the mythical creature, which she teamed with a dark lipstick and messy updo.

Meanwhile, her co-star Cara Delevingne looked equally glamorous in an Anthony Vaccarello studded mini dress and thigh-length Christian Louboutin boots, while Jared Leto stood out from the male stars of the film thanks to an intricately embellished blue Gucci coat.

Margot recently revealed she fell out of a helicopter while shooting the movie, leaving her bruised - but she had been most nervous about wearing towering shoes.

She said: "I'm not good in heels in the first place so I was a little nervous but we got through it. I didn't fall over, but I fell out of the helicopter, everyone remembers that one!"

The Australian beauty had to hold her breath under water for a fight scene in the film, and though she only had to master it for 60 seconds, her competitive nature pushed her to aim for five minutes.

She said: "I worked with this amazing free-diver, and he came in and I did four sessions with him. His name's Kirk.

"It's all about lowering your metabolic rate. You kinda, like, meditate underwater. It's what free-divers do, but it's amazing."

Margot explained that she was driven to hold her breath for longer in competition with her stunt double, but she was satisfied with making it as far as she did.

She said: "I got to five minutes and I was like, 'You know what? This is above and beyond what I thought I'd get to. I'm good, I'm good with five.'"

Margot is also joined in the film by Will Smith as expert marksman Deadshot and it is the second time they have acted together after appearing in comedy crime drama 'Focus' opposite one another.

The Australian blonde beauty revealed she was responsible for convincing Will, 47, to learn to swim after discovering he couldn't on the set of the 2015 film.

Margot was asked to reveal a secret about her co-star and she said: "When we first met Will didn't know how to swim. I was insistent that he get in a pool. He did lessons."

Will, who joined her for the interview, defended himself by explaining there was much call for swimming in Philadelphia where he grew up.

Will said: "Up in the city of Philly there wasn't a lot of swimming pools."

The film is based on DC Comic's anti-hero team who are recruited by a secret government agency led by Amanda Waller to execute dangerous black ops missions in exchange for clemency and saving the world from a powerful threat.

'Suicide Squad' is released on 4 August.