Kevin Costner is in final negotiations to join the cast of Quentin Tarantino's revenge-driven "Southern" Django Unchained. Jamie Foxx has already been cast Django, a freed American slave who teams with a German bounty hunter [Christoph Waltz] to save his wife from an evil plantation owner Calvin Candie [Leonardo DiCaprio]. Deadline report that Costner will play 'Ace Woody', a henchman of Candie's responsible for training the slaves to fight. Samuel L. Jackson is also attached to star. Django Unchained hits theaters Christmas Day 2012.