Scooby-Doo and Scrappy-Doo

The Creature Came from Chem Lab (5x7)

:

The kids head to Hillside High, to help Daphne's cousin Jennifer out. It seem that a creature from the chemistry lab has been scaring off students and forced the school to cancel it's dance. Does it have something to do with Professor Marcin, who believes kids should do school work and have no fun, or someone else?