Watch PewDiePie on Stephen Colbert's Late Show Tonight

YouTube sensation PewDiePie, whose real name is Felix Kjellberg, will appear on The Late Show With Stephen Colbert tonight. We don't know what he'll talk about, but Colbert has booked him for an interview. In addition, PewDiePie will do some kind of "demonstration," possibly for his new mobile game.

Colbert's other guests tonight include American politician John Kerry and Homeland actress Claire Danes. The Late Show With Stephen Colbert airs at 11:35 PM EDT tonight on CBS.

With close to 40 million subscribers, PewDiePie--famous for his "Let's Play" gaming videos--is arugably YouTube's biggest name. In 2014, he reportedly earned $7.5 million, and later responded to critics by saying "money doesn't make you happy."

His new mobile game, Legend of the Brofist, is a 2D platformer starring himself and other popular YouTube streamers. The game is available on iTunes and Google Play today for $5.

PewDiePie isn't the only gamer who will appear on The Late Show With Stephen Colbert this week, as No Man's Sky developer Sean Murray will be interviewed on the program on Friday, October 2.

Disclosure: CBS is GameSpot's parent company.