Wallace Michael Shawn (born November 12, 1943) is an American character actor, voice actor, playwright and essayist. His film roles have included those of Wally Shawn (a fictionalized version of himself) in the Louis Malle directed comedy-drama My Dinner with Andre (1981), John Lahr in Prick Up Your Ears (1987), Vizzini in The Princess Bride (1987), Mr. James Hall in Clueless (1995) and providing the voice of Rex in the Toy Story franchise. He has also appeared in a variety of television series, including recurring roles as Grand Nagus Zek in Star Trek: Deep Space Nine (1993–1999) and Cyrus Rose in Gossip Girl (2008–2012).