Turns out Hef's 19-year-old handpicked twin successors to the throne of Holly, Bridget and Kendra come with a checkered past. Karissa (left) and Kristina Shannon (right) -- who have recently moved into the Playboy Mansion -- were both busted by St. Petersburg, Fla. police for felony aggravated battery back in January. They both received probation and were ordered to pay restitution to the two victims.

UPDATE 6:40 PM PT: We just talked to a relative of one of the victims and here's what they tell us went down. The twins went out after work with one of their Wing House co-workers, Erica Civello, to a house party. Kristina allegedly started arguing with Erica, and Karissa came up behind her and hit Erica over the head with a bottle of beer and they both "jumped her." Erica suffered a concussion.