Karen Gillan is joining the 'Guardians of the Galaxy' cast.

The 'Doctor Who' star - best known for playing the Time Lord's feisty sidekick, Amy Pond, in the British sci-fi series - is being lined up to play the female villain in Marvel's big-budget superhero film, according to The Hollywood Reporter.

The Scottish actress is the latest addition to James Gunn's movie, which follows a team of heroes with special powers who are tasked with protecting the universe.

Chris Pratt is already on board as the group's leader, the Star-Lord - otherwise known as Peter Quill - while Zoe Saldana will play superhuman vixen Gamora, and Dave Bautista is set to portray muscular henchman Drax the Destroyer.

The team also includes Rocket Raccoon, a crime-fighting raccoon, and Groot, a sentient tree, but the parts have yet to be filled.

Karen is likely to join a rival villainous team comprised of Michael Rooker, who will star as main antagonist Yondu, and Lee Pace, while fellow British actress Ophelia Lovibond is also rumoured to be playing a villain.

It was recently reported six-time Oscar nominee Glenn Close is in negotiations to star as a leader of intergalactic space patrol group Nova Corp, after John C. Reilly was offered the role of Rhomann Dey, a leader in the Corps.

'Guardians of the Galaxy' is scheduled for an August 2014 release.