Jeff Vasishta Cash Money Records co-founder Bryan “Birdman” Williams has officially flown the coop, finally ridding himself of a luxurious mansion on Miami Beach’s Palm Island that had become a decadent albatross around the hip-hop mogul’s tattooed neck.For the last three years, the palatial pad had been subject to foreclosure proceedings, complications which forced Williams to unload the capacious, nearly 20,000-square-foot playpen for $10.9 million — a punishing loss on the $14.5 million he