"We all agree on a take on you, which is your seniority," O'Brien said, as McCain, 71, pretended to fall asleep in his chair.
Speaking for all late night comedians, O'Brien said, "we're tired of this take on you," and asked the Arizona senator to give them some fresh material.
"Do you have a kooky uncle, do you have bad breath, webbed toes, anything?" O'Brien asked.
"All of the above," McCain answered before offering up alternative fodder.
"I was able to get shot down, intercept a surface-to-air missile with my plane," said the former Navy pilot and Vietnam War prisoner of war.
"People don't really laugh at that," O'Brien pointed out.
McCain got in some jokes of his own, poking fun at "the cable monsters," his new name for cable news networks.
McCain, who has already had one cable movie made about his life, was then subjected by O'Brien to a series of casting suggestions for another movie about his quest for the presidency and his current search for a running mate.
Playing McCain? Tim Conway. Playing one-time Republican rival Mitt Romney? "Any local weatherman," said O'Brien.
