In what he billed as "the greatest TV crossover since The Flintstones met The Jetsons," comedian and satirist Stephen Colbert traded guest appearances with Fox News host Bill O'Reilly Thursday night.

The typically aggressive O'Reilly appeared much gentler and generally bemused while interviewing Colbert for the "No Spin Zone" segment of The O'Reilly Factor.

Conservative TV pundit Bill O'Reilly, left, poses with Stephen Colbert, host of Comedy Central's The Colbert Report, at the TIME 100 event in New York in May 2006.Conservative TV pundit Bill O'Reilly, left, poses with Stephen Colbert, host of Comedy Central's The Colbert Report, at the TIME 100 event in New York in May 2006.
(Time Magazine/ Ivan Villegas/ Associated Press)

"Who are you? Are you Colbert or Colbert?" O'Reilly demanded at one point, pronouncing the "t" in one case, leaving it silent in the other (as the comedian does on his Comedy Central program).

"Bill, I'm whoever you want me to be," Colbert answered.

Later, on The Colbert Report, the comedian gently poked fun at the Fox News pundit, and even set him up to make a jab at a competing network he has criticized as "liberal-leaning."

When Colbert asked what was "destroying America" more: activist judges, illegal immigration, gay marriage or NBC, O'Reilly replied "NBC" without hesitation.

O'Reilly also jokingly blamed some audience booing upon his arrival on Colbert's colleague Jon Stewart, host of sister news satire The Daily Show.

Colbert based the tough-talking, ultra-patriotic American persona for his current affairs parody The Colbert Report on right-wing hosts and shows like O'Reilly and his O'Reilly Factor, the top-rated program in U.S. cable news.

The two shows, which are both filmed in Manhattan, were taped early Thursday evening, one after the other.

Meeting with 'Papa Bear'

Colbert, who is seen in Canada on The Comedy Network, had been promoting the appearance of O'Reilly — whom he often refers to as "Papa Bear" — on his show for the entire week.

On Thursday, the Colbert Report set was decorated with a large "Mission Accomplished" banner and a portrait of O'Reilly placed above a fireplace. The banner was a reference to one with the same message that was behind U.S. President George W. Bush aboard the USS Abraham Lincoln aircraft carrier when he gave a speech on May 1, 2003, basically declaring victory in Iraq. 

At the end of Thursday night's show, after O'Reilly had left, Colbert also proudly pulled out a microwave he had smuggled out of the O'Reilly Factor green room.

A spokesman for Fox News confirmed that the comedian had indeed taken the microwave, but added that it was in good fun.

"He's got such nerve," Canadian comedian and Royal Canadian Air Farce star Don Ferguson said of Colbert, whose show debuted in the fall of 2005.

"He can take on these broadcasters — you know, the Rush Limbaughs and the Bill O'Reillys — and beat them at their own game."

With files from the Associated Press