Who is Dean Marymount from The It Girl and what is their importance?

Dean Marymount is the headmaster of Waverly Academy. He is described as formal and stringent. Marymount prides himself on students following the rules, though he often makes exceptions for wealthy legacy students. The Dean intends to humiliate and expel Jenny to make an example of her, but he is thwarted when Easy takes responsibility for his after-hours visit to the girls' dorm.