VIDEO: Billy Crystal, Jimmy Fallon Star in 'Schmuck Dynasty' on LATE NIGHT

Comedy legend Billy Crystal stopped by last night's LATE NIGHT WITH Jimmy Fallon. On the show, Jimmy and Billy Tested out some new technology that allows them to speak for each other. Later in the show, Billy takes partial credit for the success of "Duck Dynasty" - after all, years ago he launched a show called "Schmuck Dynasty".

Check out the clips below!

Billy Crystal will return to Broadway this fall for a 9-week-only limited engagement of his Tony Award-winning, record-breaking play 700 Sundays. This will mark the final engagement of this production. Previews will begin Tuesday, November 5, 2013 at the Imperial Theatre (249 West 45th Street) with opening night scheduled for Wednesday, November 13, 2013 and a final performance set for Sunday, January 5, 2014. 700 Sundaysis performed and written by Mr. Crystal with additional content by Alan Zweibel and direction by Des McAnuff.

700 SUNDAYS, an autobiographical journey, is an original two-act play in which Billy plays numerous characters that have influenced who he is today. It deals with his youth, growing up in the jazz world of Manhattan, his teenage years, and finally adulthood. It is about family and fate, loving and loss.

Photo credit: Lloyd Bishop/NBC