Mr. Garrison
In a fictional crossover psychotherapy session with Dr. Katz (from another Comedy Central series) in "Summer Sucks", Katz suggests that Mr. Hat was a personification of Mr. Garrison's "gay side". Garrison rejected this, and Katz was never able to counterpoint because he was killed shortly afterward by a gigantic novelty firework. Despite this suggestion, Mr. Garrison retained use of Mr. Hat even after coming out as gay, during the period when both were seen to be teaching kindergarten. Mr. Hat is permanently abandoned in favor of Mr. Slave once Mr. Garrison begins teaching fourth grade.