David Letterman crashed The Tonight Show on Monday night to reunite with Paul Shaffer and poke fun at Jimmy Fallon.

Feb. 11 (UPI) -- David Letterman joined Jimmy Fallon during his monologue on The Tonight Show Monday. "Is this the 23rd hour of the Today show?" asked the former Late Show host, feigning confusion, ...

On Feb. 10, David Letterman stopped by “The Tonight Show Starring Jimmy Fallon” while his former bandleader, Paul Shaffer, ...

"Is this the 23rd hour of The Today Show?,” Letterman asked as he wandered onto the stage to greet Jimmy Fallon.

Letterman has kept busy since stepping away from late-night duties in 2015, most notably in his Netflix series, My Next Guest Needs No Introduction, with David Letterman. His most recent guests ...

By Rick Porter Television Writer David Letterman — with help from some flour tortillas — made a return to the late night stage Monday. “Paul and I used to do a show pretty much exactly like ...

Last night, the great David Letterman made a rare appearance on the Tonight Show right in the middle of Jimmy Fallon‘s monologue. Catching the audience – if not Fallon – by surprise ...

David Letterman made a surprise cameo on The Tonight Show Starring Jimmy Fallon on Feb. 10, interrupting Fallon's monologue ...

On Feb. 10, David Letterman stopped by ... “That was lame,” Letterman said after they finished making the clip. The comedy legend then said he wanted to hit Fallon in the face with a ...

Letterman proceeded to slap Fallon across the face with tortillas, even letting Shaffer get in on the action. Fallon also got in a shot of his own, with the Emmy-winning host responding, “I ...