Most fans of Randy Harrison may imagine the actor as a serious guy.

Harrison first came to the public eye in 2000 playing boyish Justin Taylor for five years in Showtime’s Queer as Folk. Since then he’s racked up some heavy duty credits including most recently as Pryor in Angels in America at Berkeley Rep, George in Sunday in the Park with George at the Guthrie, and as the Master of Ceremonies in the national tour of Cabaret. Closer to Connecticut, he’s been a regular during summers in at the Berkshire Theatre Festival playing in Waiting for Godot, Equus, Endgame, Mrs. Warren’s Profession, and One Flew Over the Cuckoo’s Nest, among other works.

But Harrison, 41, will tap into his wild comic side when he joins the cast in Christmas on the Rocks at TheaterWorks playing through Sunday, Dec. 23. Harrison succeeds Matthew Wilkas in the show at the downtown Hartford theater. (Wilkas will be shooting in a new sitcom series starring RuPaul)

Christmas on the Rocks is an anthology of seven very short plays with a singular premise. The plays take an iconic kid characters from a Christmas film, story, or TV show and imagines them as a troubled adults. Think Herme from Rudolph the Red-Nosed Reindeer, Tiny Tim from A Christmas Carol, Ralphie from A Christmas Carol, and Charlie Brown arriving in a lonely bar on Christmas Eve to share their troubles with a sympathetic bartender. Playwrights include Theresa Rebeck (Bernhardt/Hamlet), Jonathan Tolins (Buyer and Cellar), John Cariani (Almost, Maine),Jacques Lamarre (I Loved, I Lost, I Made Spaghetti), Jeffrey Hatcher (Tuesdays with Morrie), Edwin Sanchez (Clean), and Wilkas and Jenn Harris.

The theater’s producing artistic director Rob Ruggiero approached his playwright pals to be part of his alternative holiday proposal.

“But I never thought in my wildest dreams that we would be returning for a sixth season,” says Ruggiero.

Part of the appeal is that new plays have rotated in and out of the show, which provides something fresh every season. Also keeping it bright and shiny is a new cast member here and there.

Harrison joins pal Jenn Harris, who plays the female holiday characters and has been with the production for the last five years. Also returning is Tom Bloom as the bartender who listens with a sympathetic ear to the characters’ wild woes.

Harris first met Harrison in the Berkshires “where we bonded over karaoke” and has also worked together on her web series New York Is Dead (“about climbing your way to the middle”). Harrison also joined her in the cast of the popular off-Broadway parody Silence! The Musical, a spoof on Silence of the Lambs.

“I’ve done comedy a lot in New York with Jenn,” says Harrison “but it’s not something I was known for in the Berkshires certainly. But comedy is a different beast and requires a bit more precision and timing. You’re more aware if you’re succeeding or failing in comedy and it feeds me as an actor in a different way.”

He says that after doing the epic drama Angels in America “which placed such an emotional burden on me, it’s going to be fun just to be goofy—and I definitely respond to the absurd.

“I’ve never done a Christmas show, but I thought if I ever did it would be this one because though it’s still nostalgic and hopeful, there’s also just a bit of the holiday melancholy in it, too. Plus, it has a sort of an adult humor, which I very much appreciate.”

“Randy’s a smart actor who can go deep, but he’s also very funny,” says Harris, who plays Clara from The Nutcracker, Karen from Frosty the Snowman, Zuzu from It’s a Wonderful Life, and the Little Red-Haired Girl from A Charlie Brown Christmas.

Harris offers a bit of advice to her friend Harrison in approaching the decidedly twisted show: “This show is silly and fun. Don’t worry if the tone is correct or not,” she says laughing. “The bigger the better.”