Knoxville is set to star in Mt. Mystic, the comedy series based on a YouTube pilot. The mockumentary comedy follows a dysfunctional team of park rangers as they face budget cuts, drama, and chaos — both natural and supernatural — in the most unpredictable state park on Earth. Mystic State Park. Knoxville plays Lieutenant Gibbard, a newly installed lieutenant who is eager and deeply unprepared for the sheer volume of personalities around him.