NBC's Community was an imaginative comedy show that blended meta-humor and pop culture references to create some of TV's most creative episodes. These quirky and hilarious storylines were full of lovable characters at Greendale Community College, especially the central study group. Throughout the show's six-season run, there have been various guest or recurring characters that well-known actors played.
Source:https://www.cbr.com/community-actor-guest-stars/