Once Upon A Time fans, prepare to meet the vainest of villains. For a Beauty and the Beast-themed episode, Sage Brocklebank (Psych) has been cast as Gaston, the narcissistic dude who enjoys a good hunt and has Belle in his sights. (E! online first reported the news.) Lost‘s Emilie de Ravin already has been tapped to play the booksmart stunner. The episode is slated to air Feb. 12 on ABC.