Dwayne "The Rock" Johnson interupted "The Tonight Show Starring Jimmy Fallon" Wednesday night via Facetime to issue the host an impossible strength challenge: pull a 250-pound rock across his studio.

Fallon has launched such celebrity sketches as "Wheel of Musical Impressions," "Musical Genre Challenge," and "History of Rap" on "The Tonight Show" which have been viral hits on YouTube and Facebook.

Greg Gutfeld, host of Fox News’s late-night show Gutfeld!, will appear as a guest on The Tonight Show Starring Jimmy Fallon Thursday, a crossover he expects will be “fun.” Gutfeld! is growing in ...