.shimeji {
    position: fixed;
    z-index: 10;
}

.shimeji img {
    position: absolute;
}

.shimeji img.reverse-horizontal {
    transform: scaleX(-1);
    transform-origin: 50% 50%;
}
.shimeji img.reverse-vertical {
    transform: scaleY(-1);
    transform-origin: 50% 50%;
}