Bibi and Tina, The Horse at School

Shortly before the summer break, Bibi is allowed to visit Tina's class, and ends up summoning her favorite mare Sabrina. The kids love it, but all the whinnying and laughing gets on their teacher's nerves. Thinking a little joke might lighten him up, Bibi casts a spell to make him whinny like a horse. But then the reverse spell won't work!