Give a big Greendale welcome to John Goodman: The Roseanne vet has enrolled in Community for a six-episode guest stint, EW has confirmed. (Vulture first reported the news.) Goodman will play Vice Dean Laybourne, a distinguished, confident administrator who runs the school of Air Conditioning Repair at Greendale Community College — and one who locks horns with Dean Pelton (Jim Rash). At Comic-Con this weekend, the NBC comedy announced that Michael K. Williams (The Wire) will guest star in three episodes as Prof. Kane, a new biology teacher who clashes with Jeff (Joel McHale). Both Goodman and Williams appear in the season 3 premiere, which airs Sept. 22.