Mr. D season 5 episode 11
Episode title: Hell-icopter Mom
When he attempts to reign in a bratty student, Gerry is faced with the wrath of his notoriously overprotective and obnoxious mother. Upon realizing that she has fallen into the role of staff "punching bag," Bobbi attempts to transfer the title onto another staff member. Meanwhile, Ricki sells pencils to Robert and drives a hard bargain.
