It's not her beauty... IT'S HER BOOTY!!!

Super-groupie Kat Stacks is finally a free woman.
Kat -- who came to the U.S. from Venezuela when she was eight -- had spent the past year in a deportation center in Louisiana after being arrested in Florida for carrying a concealed firearm and disorderly conduct. But in her appeal, her attorney noted that her young son was born in the U.S. and said that she'd been coerced into the sex trade.
An appeals board voted two-to-one to release her, concluding that even though her public persona "is disturbing and in no way a positive contribution to society... other compelling factors, particularly her long history of abuse, outweigh the negative factors." She was released yesterday (Thursday) when a federal judge signed off on the appeals board's decision.

Kat -- whose real name is Andrea Herrera -- is widely known for claims that she's bedded such MCs as Soulja Boy and Nelly.