8. Patrick Isakson
Dr. Isakson is a Professor of Women's Studies at Greendale as well as the Dean of Admissions. He is not as well-known as the other professors on this list because the character has never appeared in-person on an episode of the show. Portrayed by show creator Dan Harmon, Isakson appeared in a series of webisodes that aired prior to the show's debut. In these videos the Women's Studies teacher outlines the 5 A's to consider when deciding to enroll at Greendale: Accessibility, Affordability, Air Conditioning, Awesome New Friends, and A Lot of Classes. The webisodes end with a series of outtakes in which Isakson displays hostility with many of the students who are aiding him with the filming. While he never appeared in person on the actual show his face has shown up on a few flyers. After a rogue speakeasy was opened in defiance of a school-wide alcohol ban, Dr. Isakson's face was seen posted with a warning to not serve him. Considering he was teaching prior to the show's beginning and is apparently around to this day he can consider himself one of the most tenured professors on Greendale's payroll. http://youtu.be/i3z5QO2O3cU