Star vs. the Forces of Evil

St. Olga's Reform School for Wayward Princesses (1x19)

Air date: Aug 10, 2015

Star and Marco go undercover as new princess students in order to break Flying Princess Pony Head out of St. Olga's on her birthday. They discover that Pony Head has been brainwashed to be a compliant princess and try to evade the robot guards and the reform school's headmistress Miss Heinous.