The Powerpuff Girls Season 5 Episode 11 Substitute Creature ( Air Date 2003-09-26 ) Genre Action & Adventure, Animation, Comedy, Kids, Family category. Overview "When Ms. Keane gets sick she hires a substitute teacher named Mr.Green to run the class in her absence. Unfortunately because of his monstrous appearance the girls assume he's a bad guy and try to save their classmates from him.".