Mrs. Munger is the teacher and main character of the show. She is voiced by Peter Hastings. Although she gets frustrated toward the class, she manages to take things in stride. Mrs. Munger also tells the class regularly to "simmer" when things get crazy. She says it like "Simmer class, simmer!" At times, when she can't really get the class to simmer, she just yells "HEY!"
Mrs. Munger was really Mrs. Kathleen Foresman from Woodbridge Middle School in Woodbridge, VA. The picture was taken in 1975. Foresman and some of her former students sued Disney over the use of actual school portraits to use to create characters.