An old raven tells his grandson the legend of Karl, a young raven with the mind of an inventor. Karl dreams of becoming one of King Felix’s courageous mail ravens. When King Felix is lured away from his castle by the envious King Rudolph, Karl decides to prevent Rudolph’s impending siege. With the help of the castle’s farm animals, Karl plans and constructs a gigantic mechanical dragon that scares off King Rudolph along with his entire army. Karl and the animals are honored, and as it turns out, the grandfather telling the story was Karl himself.