When Serena Williams invites you to her costume party, there's only one rule -- go big or go home ... so says ex-NFL star Bryant McKinnie.
Bryant dropped $600 to get body painted up like the Incredible Hulk ... and the guy who applied it, Jesse Thoreson, says the process took almost 3 HOURS!
But BK wasn't the only NFL star who went big for the party -- Vernon Davis became the Mad Hatter.