img.monty-python-foot {
    position: absolute;
    top: -900px;
    z-index: 99;
    animation: move_down 4s;
}

@keyframes move_down {
    0% { transform: translateY(-1200px); }
    50% { transform: translateY(800px); }
    100% { transform: translateY(-1200px);
    }
}