The Mad Pantser is the nickname of the pantser in Greg's school. It is unknown who The Mad Pantser is, but a clue is given as four boys in Greg's school are affected by chicken pox, and no pantsing incidents happened after they got sick. The Mad Pantser was involved in several incidents and pantsed even Vice Principal Roy. In the Valetine Day Dance, he pantsed Rowley. He appears only in Diary of a Wimpy Kid: The Third Wheel.