프래니는 외모를 예쁘게 꾸미는 일에 도통 관심이 없었어요. 그래서 엄마가 화장품과 헤어드라이어, 헤어스프레이 같은 것들을 왜 좋아하는지 알아내려고 엽기 실험을 시작했지요. 그런데 프래니가 새로 발명한 약품을 머리에 바르자, 머리카락이 쭉쭉 자라더니 시내를 돌아다니며 말썽을 일으키지 뭐예요? 과연 프래니는 머리카락 괴물을 물리치고 평화를 되찾을 수 있을까요?

Franny K. Stein is back with another laugh-out-loud experimental adventure in the eighth book in the Mad Scientist series from Jim Benton, the New York Times bestselling author-illustrator of the Dear Dumb Diary and It’s Happy Bunny series.

Franny K. Stein isn’t a fan of glamour. She doesn’t style her hair, the thought of wearing makeup makes her want to gag, and she couldn’t care less about wearing dressy dresses when she’d much prefer her lab coat.

But sometimes Franny wonders if her mom wishes she were different. Which gives Franny an idea…for an experiment! What if she can turn the beauty products her mom loves into something more exciting?

Every experiment has its experimental error, and when Franny’s hair takes on a life of its own, Franny must save the day (and her hair) to finally realize her mom loves her just the way she is.