Professor Haydn Hippo is a music instructor, conductor and toy mascot inthe music class at school. He is particularly fond of the music of Fran z Joseph Haydn. He can't climb stairs very well, so Clara Schumann-Cat kindly gives him a ride on her back, while he holds on tightly to her collar. Professor Haydn Hippo is a replica of the character first introduced in Lesson Book 3. Suggestions are made in the Lesson Book for integrating the animals into the lesson.