public static Entity createMammothTank(World world, float x, float y) {
Entity e = world.createEntity();
world.getManager(GroupManager.class).add(e, "tanks");
e.addComponent(new SpatialForm("mammothTank"));
e.addComponent(new Velocity());
e.addComponent(new TurnFactor());
e.addComponent(new Tower());
e.addComponent(new Health(110, 150));
e.addComponent(new Ammo(78, 150));