Former “Suddenly Susan” star Kathy Griffin is ripping Hollywood’s hottest stars to shreds in a foulmouthed new “comedy” routine that’s so vicious it’s stunned even her most diehard fans!

Catty Kathy skewers everybody from Mariah Carey to Barbara Walters to Stephen Baldwin in a series of celebrity put-downs that some say is long on nasty but short on laughs.

Of veteran newswoman Walters, the acid-tongued comedienne says: “Barbara used to be on top of her game, but now she sucks and is completely insane.”

And after lambasting actress Sharon Stone, callous Kathy said she figures she’d better watch her back “because Sharon is just a white Whitney Houston and she’ll cut ya!”

In a recent tongue-in-cheek stand-up act at the Laugh Factory in Hollywood, the carrot-haired “funnygal” also accused fellow “Celebrity Mole: Hawaii” star Stephen Baldwin of trying to choke her one morning on the set of the show.

She called the famous Baldwin bro “a bipolar, crazy m—–f—–,” — no doubt leaving the actor wishing he’d taken a tighter hold on her throat when he had the chance.

“We (she and Baldwin) went back and forth for a few minutes while Frederique, who is a former model — and I do mean FORMER, because that bitch is going down fast — sat there nibbling on a muffin,” Kathy told her shocked audience. “I hate Frederique because she is so incredibly stupid, but she thinks she’s smart because she can read The New York Times!”

And as if that weren’t mean-spirited enough, Kathy unleashed her most venomous attack of the night on Liza Minnelli and her husband David Gest. Saying she’d heard the couple planned to adopt four Thai babies, she spewed: “Now you know David is going to (molest) those kids!

“And every time you ask Liza how long she has been sober, she says two weeks,” Kathy added. “So you know she’s still doing drugs. But I hope those two queens will be happy.”

At one point in her 21¼2-hour show, Kathy narrated as TV monitors played an excerpt from a clip in which Mariah Carey gives viewers a tour of her home. The diva showed the audience a closet containing hundreds of white T-shirts, all appearing to be exactly alike.

After Mariah told viewers she still does some of her own housework, the comedienne quipped, “Does Mariah know that polishing her American Music Award doesn’t constitute housework?”