Mylène Haprèle is a major character of Miraculous: Tales of Ladybug & Cat Noir. She is a student at the Collège Françoise Dupont and a former student of Miss Bustier's class, before she became mayor of Paris. When the Miraculous is inhabited by Mullo, Mylène becomes Polymouse, a mouse-themed superhero with the power of Multiplication who helps Ladybug and Cat Noir during "particularly difficult missions" in the fourth season.