has since directed several of his plays. As a stage actor, he has appeared mostly in his own plays and other projects with Gregory. He made his film debut in 1979, playing Diane Keaton's ex-husband in Woody Allen's Manhattan and an insurance agent in Bob Fosse's All That Jazz. His best-known film roles include Earl in Strange Invaders (1983) and Mr. Hall in Clueless (1995). After seeing his performance in My Dinner With Andre (1981), casting director Janet Hirshenson was so fond of his delivery of the word "inconceivable" that she cast him as Vizzini in The Princess Bride (1987). Other roles include Baron Von Westphalen in Southland Tales, Cyrus Rose on Gossip Girl, and Ezra in The Haunted Mansion (2003). His rare non-comedic film roles include two collaborations with Andre Gregory and Louis Malle: the semi-autobiographical dialogue My Dinner with Andre, and a combined production-and-backstage-drama of Uncle Vanya titled Vanya on 42nd Street. Shawn quite often appears on television, where he has appeared in many genres and series. He has had recurring roles as the Grand Nagus Zek on Star Trek: Deep Space Nine, Stuart Best on Murphy Brown, Jeff Engels on The Cosby Show, Dr. Howard Stiles on Crossing Jordan, Arnie Ross on Taxi, Charles Lester on both The Good Wife and The Good Fight, and a reprisal of his role as Mr. Hall on Clueless (based on the film). He appeared in the 1985 music video for Chaka Khan's "This Is My Night". On February 4, 2010, Shawn appeared as Alan Rubin on The Daily Show with Jon Stewart. He appeared in Vegas Vacation as Marty. A Master Builder opened in New York City in June 2014. In 2018, he joined the cast of Young Sheldon in the recurring role of Meemaw's boyfriend and Sheldon's physics professor, Dr. John Sturgis. Shawn stars in Woody Allen's 2020 film Rifkin's Festival, set in San Sebastian, Spain. Shawn was honored in 2005 with the PEN/Laura Pels International Foundation for Theater Award as a Master American Dramatist. Voice acting Shawn is a voice actor for animated films and television series, including Rex in the Toy Story franchise, Monsters, Inc. (2001) during the outtakes in the closing credits, Kingdom Hearts III, Mr. Gilbert Huph in The Incredibles, Principal Mazur in A Goofy Movie, Bertram in Family Guy, Munk in Happily N'Ever After, Purple Pirate Paul in Tom and Jerry: Shiver Me Whiskers,