Wallace Michael Shawn (born November 12, 1943) is an American actor, playwright, essayist, and screenwriter. He is known for playing Vizzini in The Princess Bride (1987), Mr. Hall in Clueless (1995), and voicing Rex in the Toy Story franchise (1995–present). Shawn also appeared in The Bostonians (1984), Prick Up Your Ears (1987), Vanya on 42nd Street (1994), The Double (2013), Maggie's Plan (2015), and Marriage Story (2019). Wikipedia