The Headmaster is the fake Headmaster of the Super Moshiversity. He is a member of C.L.O.N.C., and is a MustachioGlump in disguise. Every night (until his defeat) he would play an organ to hypnotise every student in the Moshiversity. After being hypnotised, they would go on a rampage and destroy everything. One night, a Super Moshi found him performing his evil deeds on the organ (using ear plugs to cancel the noise out) and defeated him by holding off Glumps with a sling shot. It is unknown what happened to him after his defeat. He was mentioned in the article by Roary Scrawl about all the previous "baddies" so it is possible that there was intentions for him to return.
Caught playing a hypnotic organ at the Super Moshiversity, he was certainly up to no good. Turned out the Headmaster was a card carrying member of C.L.O.N.C.!
The Headmaster wears a blue robe, with purple at the arm holes. He has a purple neckhole (much like a turtleneck) and a blue Graduation Hat. He has pinky/purpley hands that look quite like Dr. Strangeglove's glove.