@keyframes img1to2 {
    0% { background-image: url(images/cat-feth.jpg)}
    20% { background-image: url(images/cat-pelo.jpg)}
    40% { background-image: url(images/cat-mar.jpg)}
    60% { background-image: url(images/cat-aste.jpg)}
    80% { background-image: url(images/cat-raki.jpg)}
    100% { background-image: url(images/cat-feth.jpg)}  
}

.anidiv {
    z-index: 0;
    position:absolute (0,0);
    width: 800px;
    height: 450px;
    animation-name: img1to2;
    animation-duration: 18s;
    animation-iteration-count: infinite;
    border-width: 0px;
    border-radius: 50px;
}