Lady Gaga and Justin Bieber to play aliens in 'Men in Black 3'

Pop stars Lady Gaga and Justin Bieber are set to play aliens in the upcoming sci-fi comedy "Men in Black 3," according to E! Online.

The outlandishly-dressed female singer and the kid with the unnaturally golden hair will probably not have major roles, according to director Barry Sonnenfeld, but will show up on "on the surveillance board," presumably at MIB headquarters. They'll be joined by at least one other celebrity alien, director Tim Burton.

"The challenge," said Sonnenfeld "is getting celebrities that are famous, will give you permission and won't be like 'Who's that guy?' in 10 years."