Lisa Lampanelli -- I'm One of Those Skinny Bitches Now!

Comedian Lisa Lampanelli is hysterical ... but there ain't nothing funny about how great she looks since her dramatic weight loss.

After recently undergoing gastric sleeve surgery to remove 85% of her stomach, the 51-year-old ball buster showed off her new curves in NYC on Tuesday (left) -- and looks remarkably different from even just five months ago (right).

Lisa is no joke.