<div class="cat">
  <img src="https://cdn.pixabay.com/photo/2016/03/31/17/33/icons-1293736_960_720.png" />
</div>

.cat img {
  width: 200px;
  margin: auto;
  animation-name: rotate;
  animation-duration: 10s;
  animation-delay: 2s;
}

@keyframe rotate {
  0% { transform: rotate(0turn); }
  100% { transform: rotate(6turn); }
}

@-webkit-keyframes rotate {
  0% { transform: rotate(0turn); }
  100% { transform: rotate(6turn); }
}