Dennis Barton Dugan is an American film director, actor, comedian and screenwriter from Wheaton, Illinois who directed several films featuring Adam Sandler including Happy Gilmore, Big Daddy, Jack & Jill, Grown Ups, I Now Pronounce You Chuck & Larry and You Don't Mess With the Zohan. He also directed Beverly Hills Ninja and The Benchwarmers.
When Dugan was directing the final episode of Moonlighting (1985), actor Ronny Graham fell ill. Dugan put on Graham's outfit and did the scene. As an in-joke for the fans of the show, he was billed as "Walter Bishop" (the character he had played the year before).
An accomplished painter, he's had several gallery shows in the Los Angeles area.