public class AnimalSimulator {

    public static void main(String[] args) {
        Animal animal = new Cat();
        animal.display();
        animal.doMove();

        Animal anotherAnimal = new Fish();
        anotherAnimal.display();
        anotherAnimal.doMove();

        Animal theOtherAnimal = new Bird();
        theOtherAnimal.display();
        theOtherAnimal.doMove();
        theOtherAnimal.setMove(new WalkBehavior());
        theOtherAnimal.doMove();
    }
}