Herr Liszt was the tutor that Bruno's dad hired for the children. He rode his bicycle to the house everyday and worked with Gretel and Bruno to improve their schooling. Herr Liszt often gave Bruno books to read and believed that Jews are evil.
He believed that adventure storybooks were evil, and Bruno shouldn't read them. He had him read about history and explorers instead.
He also tutored Gretel, and was extremely proud when she was keeping track of the soldiers on the maps with pins glued onto her walls.