Christopher Lloyd Big Bang Theory

The Big Bang Theory: Christopher Lloyd Set to Guest-Star in Mystery Role

Dr. Sheldon Cooper is about to meet Doc Brown.

It was announced on Wednesday that CBS’ The Big Bang Theory has tapped Back to the Future funnyman Christopher Lloyd to guest-star in the Thursday, Dec. 1, episode.

In touting the casting, the series’ executive producers said that they were “so excited” to be working with the veteran actor, whose small-screen credits include appearances on everything from Cheers to Chuck, of course his 1978-83 stint as Taxi’s Reverend Jim Ignatowski, and an upcoming visit to Syfy’s 12 Monkeys.

The EPs added that, although they weren’t revealing exactly who he’d be playing — or whether time travel would be involved — “We think we’ve created a fun part that fans will really enjoy.”

Who do you imagine Lloyd will be playing? Maybe they’ve found a way to give him a scene or two with fellow Taxi alum Judd Hirsch (aka Leonard’s father)? Hit the comments with your theories and/or hopes.