Calvin Waffle is still 100% weird in the newest installment of David A. Adler's laugh-out-loud chapter book series, Danny's Doodles Danny Cohen and his brainiac sidekick Calvin Waffle are back with a brand new experiment! Something is amiss in Danny and Calvin's fourth-grade class when their loud, rule enforcing teacher Mrs. Cakel, suddenly transforms into a whole new person. Danny and Calvin decide the only way to find out what's really going on is to spy on their personality switching teacher. But spying soon leads to a greater mystery filled with dog chasing, jelly injected donuts, peanut butter induced experiments, riddle mania, and more!