Heidi Johnson is a recurring character and minor antagonist appearing in the Forever Sophomores series. She is Mrs. Parson's assistant in Tom, Trent, Willy, and Caillou's Marine Science class. She has been appearing in almost every episode since "The Learning Continues".
Ms. Johnson is very kind and helpful. She often helps her students with classwork. She often acts very strict whenever one of her students goof around. Ms. Johnson is currently Tom and the gang's main Marine Science teacher, since Mrs. Parson left to take care of her baby. She has stated that every teacher she assists gets pregnant. In "The New Parson", she replaced her with Ms. Kinzoku, and later Ms. Kazaguruma. She debuted in "The Learning Continues".
Ms. Johnson has fair skin, blue eyes, and brown hair. Her outfits vary throughout the series, but she is mostly seen in 3 outfits. In the Forever Sophomores series, her usual attire consisted of a light turquoise sweater, blue jeans, and light brown sandals.
Her outfit during "The Weirdness War" consists of a gray coat over a green sleeveless blouse, khaki pants, the same sandals, and a white watch.
In Advanced Education, she can be seen wearing a white and red striped shoulder-less blouse with short sleeves, the same khaki pants from the Wierdness War, and red sandals.