<img src="https://cdn.mos.cms.futurecdn.net/snbrHBRigvvzjxNGuUtcck.jpg" />
<h2>Hover to pause</h2>

img{
  width: 200px;
  height: 200px;
  margin: 50px;
  animation-name: rotate;
  animation-duration: 3s;
  animation-iteration-count: infinite;
}
img:hover{
  animation-play-state: paused;
}
@keyframes rotate{
  from{
    transform: rotate(0deg);
  }
  to{
    transform: rotate(360deg);
  }
}