Diva Next Door! Holly Madison SLAMS Kendra Wilkinson As 'Manipulative,' Tantrum-Throwing Liar In New Tell-All: Her 18 Most Shocking Revelations

Holly Madison and Kendra Wilkinson may have seemed like best pals on iconic E! series The Girls Next Door, but in reality, the two former girlfriends of Playboy mogul Hugh Hefner were bitter enemies. In her new book, Down the Rabbit Hole: Curious Adventures and Cautionary Tales of a Former Playboy Bunny, Madison, 35, slams her former fellow Playmate as vapid, selfish and dangerous.

As soon as Wilkinson, then just 18, arrived to the Playboy mansion in 2004, she stirred up trouble. Hefner, now 89, chastised her for flirting with the butlers, says Madison.

Wilkinson lied to fans about how she hooked up with Hefner, Madison claims. The budding author says the mansion newbie had sex with the mogul before she became a "girlfriend," not after as she insists in her memoir Sliding into Home. "He never asked anyone to become a girlfriend before they joined him in bed," Madison insists.

Is anybody home? Madison says the teen stripper almost never spoke in her early days at the mansion. "She seemed to have fried her brain somewhere along the court of her life," Madison quips.

The now 29-year-old mother of two was a total brat when she moved into the mansion, demanding the biggest room, dental surgery and a car. "I have to admit, I envied Kendra's sense of entitlement. I had felt so lucky just to scrape by…and here was a rookie who had just gone all the way with an old dude and her only concerned was how big her room was going to be," Madison recalls.

Liar, liar! Wilkinson told Hefner she was a college student, not a stripper, because she got the heads up that Hef "didn't like strippers and preferred college girls," Madison writes.

Smarter than she looks? Madison claims Wilkinson said a group of Playmates offered her drugs while out at the club. Hefner promptly kicked the other girls out of the house.

Hot mess! The new girl "trashed" her gorgeous bedroom, and allowed her two dogs to relieve themselves anywhere. The room "reeked so badly of dog urine that you could smell it down the hall," Madison writes.

Wilkinson wasn't the brightest bulb. Madison recalls an instance when the blonde mispronounced Japanese wine "sake," and yelled at the waitress for not understanding her.

Mean girl! When Madison bought her a sequined skirt as a welcome gift, Wilkinson refused to accept it and snapped she would never wear it.

Dumb…or evil? Madison claims Wilkinson dumped hot candle wax all over her legs one night at a club.

When she didn't get her way, Wilkinson threw "drunken fits" and tantrums "in hopes that Hef would feel that urge to rescue her or care for her," Madison writes. "It was both manipulative and incredibly sad."

Cheater! Madison reveals that Wilkinson betrayed Hefner by dating now-husband Hank Baskett for eight months before she left the mansion.

More diva antics! Wilkinson often holed up in her room and refused to film scenes for Girls Next Door. "I would find out later that this was around the time she started secretly seeing her future husband…so maybe that factored into the equation as well," Madison says, adding that the difficult star had grown "debilitatingly insecure."

Wilkinson kicked a Playmate named Kayla Collins out of the mansion, Madison says— and rumors swirled that Baskett tried dating Collins before her.

Disappearing act: When Wilkinson began filming her spinoff show, Kendra On Top, the series' producers asked Madison to appear on the show. Immediately after the cameo, Wilkinson stopped responding to her former roommate's calls and texts.

When Madison confronted her via text, Wilkinson exploded. "WHO ARE YOU???? I DON'T EVEN KNOW YOU! WE WERE NEVER FRIENDS. IT WAS ALL JUST WORK!" she snapped. "I don't miss her," Madison writes of their strange falling out.