After Sabrina's hair gets messed up after swimming she decides to use a spell to create a shampoo to have perfect hair. The spell works and will always keep her hair perfect, but under one condition. She can't ever have water touch her hair or body. So Sabrina decides to go without bathing to keep her hair perfect. Everyone at Greendale Highschool admires her hair, but Cassandra doesen't and she decides to steal Sabrina's magic shampoo and give it out to her popular mortal friends to use. Unfortunately instead of giving them good hair it turns them into werewolves and it's up to Sabrina and Cassandra to break the spell. (thetvdb.com)