Watch David Beckham and Prince William Hang Out With Endangered Rhinos

Feb. 13, 2014 — -- Prince William, David Beckham and Yao Ming are teaming up to spread the word and protect endangered elephants and rhinos.

"Imagine if all the people in the world could fit into one stadium," Beckham opens up a new WildAid public service announcement that was shot in September 2013 and started airing last month.

"Sadly, all the wild rhinos in the world can -- with room to spare," the Duke of Cambridge says after Beckham. "For some species, it's almost too late. There are only seven Northern White Rhino left."

The trio are seen walking into Wembley Stadium in awe of the great rhinos walking around on the grass.

Beckham asks the viewers to tell their friends and family never to buy rhino horns.

"Together, we can save our wild rhinos," William says.

The final line is "When the buying stops, the killing can too."

Peter Knights, the executive director for WildAid, calls the PSA one of the "most ambitious" announcements ever.

Watch the PSA below.