But now it's been revealed who the blonde beauty pictured above on the far right is: Crystal Harris, a 22-year-old San Diego University psychology student.

The New York Daily News reports that Harris took to E!'s message boards to introduce herself to Girls Next Door fans over the holidays.

"Hef gave me permission to fill people in on the new updates as a voice from the mansion," she wrote.

And while so far it's just her, Karissa and Kristina in the Playboy mansion with 82-year-old publishing legend Hefner, Crystal wrote, "There are a couple that we have interest in... As for now, it is just us three."

It's been a complete changing of the guard in bunnyland lately. Girls Next Door stars Holly Madison and Kendra Wilkinson have escaped Hef's clutches and gotten paired off.  As for Bridget Marquardt; well, she occasionally comments to the press on Holly and Kendra's relationships.

Hefner has confirmed that there will indeed be a sixth season of the E! reality series.

Who do you most want to get to know better: Karissa, Kristina or Crystal?