Edna Krabappel
Edna smokes a lot, even inside the school. In the episode "Grade School Confidential", she gets in an intimate relationship with the school's principal, Seymour Skinner. They use Bart to give messages to each other when he is in classrooms. Bart gets angry and tells all of the students about the relationship. Skinner and Edna get fired by Superintendent Chalmers, but they get their jobs back at the end of the episode. In the episode "Bart Gets a 'Z'", she gets fired because she was drunk at the school. She gets her job back at the end of the episode because the substitute teacher also gets drunk. In the episode "The Ned-Liest Catch", she gets suspended and put in a reassignment center for hurting Bart. Bart tries to get her out, but Edna falls from a ladder. Ned Flanders stops her from falling.