Jenny McCarthy put on a serious thong and dance at the Palms Casino in Las Vegas this weekend -- and she was joined by a tattooed snake-eater and some girl with a bad case of flower-crotch.


It all went down Saturday night at Playboy's Midsummer Night's Dream Party -- check out the photos for even more jaw-droppingly sexy costumes ... oh yeah, and that guy who plays Drama on "Entourage" or whatever.

Back in New York -- Jenny's former "Singled Out" co-star Chris Hardwick told us one hell of a story involving Jenny's backside ... and it kinda explains why she was his #2 on the show.