Greendale Community College. A serious practitioner of his chosen craft, he often speaks in an exaggerated or overly dramatic fashion. He once took part in an elaborate prank involving Jeff, Annie, Dean Pelton and his good friend Officer Cackowski. He first appeared in the episode "Conspiracy Theories and Interior Design". He is portrayed by actor Kevin Corrigan.
In the study group's second year at Greendale, Dean Pelton found what appeared to be a fake course on Jeff schedule called "Conspiracy Theories in U.S. History". The name of the teacher, "Professor Professorson", seemed to be further indication of its factiousness. Beliveing Jeff had made up the class, Dean Pelton told him he would not be receiving any of the supposed credit he earned. Jeff proclames his innocence and that he met with the professor in his office every Wednesday. He offered to lead Dean Pelton to the office and an intrigued Annie followed. Jeff takes them to a door he insists is Proffessorson's office but turns out to be just a supply closet. Seemingly shocked at the turn of events, Jeff then suggests that this was all an elaborate hoax by the professor, a conspiracy to unravel for his final exam.