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.
There are roughly one-sh*t billion tropes so PLEASE look through them before adding one. Otherwise add what you like. ADDITION: PLEASE read through the trope description provided before submitting something. It's not a huge deal but too often people submit characters that don't fit just because they misinterpreted the title...
