Mr. McMcMc (voiced by Maurice LaMarchie in the pilot and Rip Taylor in the rest of the series) is Robot Jones's Math teacher. He is the teacher that is seen most often and has the most lines. Robot has already passed his class and he has ran out of assignments for Robot. Sometimes he is kind towards Robot but at other times he isn't as much. Like Principal Madman, Mr. Mcmcmc is very temperamental and childlike.

Mr. Mcmcmc’s responsible for sending Robot to detention in a furious temper in the pilot after they argued on the subject of who is more intelligent. Robot used a factual statement causing the rest of the class to burst out laughing. Unfortunately Mcmcmc took this wrongly and believed that Robot was indirectly mocking him as well as questioning his authority. With all of the pressure he felt from the students laughing directly at him, it then resulted in Mcmcmc blaming Robot for embarrassing him in front of his Math class. It also caused Robot to get into deep trouble.