'Kim Kardashian Is a Fat Donkey:' Shanna Moakler

It looks like reality star Kim Kardashian is the butt of yet another joke about her famously voluptuous backside. Model Shanna Moakler says Kardashian, 27, is a "fat donkey."

"I was at this BBQ [in July] and I saw what I thought was a donkey posing on the stairs, but much to my surprise, it was Kim Kardashian," Moakler, 33, tells TheDirty.com. "No, wait, it was a donkey!"

Moakler, who was crowned Miss USA in 1995 and was a Playboy Playmate of the Month in 2001, met Kim at a barbecue held by mutual friend Carmen Electra, where Moakler admitted throwing a drink at Kim. Moakler claims Kardashian once tried to sleep with her ex-husband, Blink-182 drummer Travis Barker.

"She's soooo f***ing fat!" says Moakler. "She's 5'2" and she's like 140 [lbs]. She was wearing a sarong to cover her huge big a**! I like a nice a** but hers is not nice!" Interestingly, Kim recently stated she weighs 120 lbs., a claim few people seem to believe.

Earlier this year, Kim's former BFF Paris Hilton also made poked fun at her gigantic bum, saying it looks like "cottage cheese stuffed inside a trash bag." Kardashian, who shot to global notoriety following the release of a sex tape, has been making the most of her 15 minutes of fame: She stars in a hit E! reality show, Keeping Up With the Kardashians, and has a film coming out this fall, Disaster Movie, co-starring Electra and fellow C-lister Vannessa Minnillo.