Kathy Griffin isn't known to have much of a filter, and on Saturday night's CNN New Year's Eve broadcast, the comedienne shed any remaining inhibitions - and her clothes.

Griffin, who cohosted the live coverage of the Times Square ball drop with Anderson Cooper, appeared feisty throughout the night, but she had one move up her sleeve that even Cooper couldn't have predicted.

As the camera cut away to shots of revelers and the Swarovski crystal ball, Griffin quickly stripped down to her bra and panties, startling Cooper and sending him into a fit of nervous giggles.

"Are you freaking kidding me?" Cooper asked, trying to compensate for an uncomfortable situation.

He then waved a "No Nudity" sign in Griffin's face.

Despite the best efforts of Cooper's crew to cover her up, however, Griffin refused to get dressed, instead waving to partygoers in Times Square and flirting with CNN contributor and former presidential adviser David Gergen.

"You're a big square who won't let me have any fun," Griffin taunted a nervous Cooper, trying to get him to follow suit. "Your turn!"

Only after Cooper cut to a back-and-forth with correspondent Gary Tuchman and his 14-year-old daughter in Central Park did Griffin finally get dressed.

But don't expect the razor-tongued comedienne to apologize for her antics anytime soon.

"I have a no-apology policy," Griffin told CBS news. "No apologies for jokes. I apologize in my real life all the time. I say ridiculous things, I make mistakes constantly.

"But when I'm on stage, I'm at a microphone ... it's a joke!"