If you want to see what funny looks like, you should see Bill Irwin in a comedy. In recent years, he’s been fairly serious, what with his stage work in shows like Who’s Afraid of Virginia Woolf (a Tony Award-winning turn opposite Kathleen Turner) or The Goat, or Who Is Sylvia? (opposite Sally Field) and his movie work as a dedicated dishwasher-loading dad in Rachel Getting Married.

But Irwin is a clown in the purest sense. The Bay Area knows him as one of the founders of the Pickle Family Circus, and his alter ego, Willy the Clown, is as beloved as they come.

We’ve seen Irwin on the American Conservatory Theater stage in the last few years, in his luminous Fool Moon project with David Shiner and the conundrum of Beckett’s Texts for Nothing, but his return as the title character in Moliere’s Scapin, ACT’s season opener, is reason to cheer.