Kathy is a negative student in Mrs. Jewls' class. She does not exist in the show. It has been said she hates everyone except her classmate Sammy, who, in the books was a dead rat that did not belong to Miss Mush.
She is known to be negative, and she hates everybody, with the exception of Sammy and Mrs. Franklin. Allison has tried to befriend her, but she always is mean in return. She sometimes makes up reasons to hate people.