@-webkit-keyframes pulse {
  from {
    -webkit-transform: rotate(0deg);
            transform: rotate(0deg);
  }
  to {
    /*
      transform: rotate(20deg);
      transform: scale(2);
    */
    -webkit-transform: rotate(180deg) scale(2);
            transform: rotate(180deg) scale(2);
  }
}

@keyframes pulse {
  from {
    -webkit-transform: rotate(0deg);
            transform: rotate(0deg);
  }
  to {
    /*
      transform: rotate(20deg);
      transform: scale(2);
    */
    -webkit-transform: rotate(180deg) scale(2);
            transform: rotate(180deg) scale(2);
  }
}

.pulse {
  /*
    animation-name: pulse;
    animation-duration: 4s;
    animation-direction: alternate;
    animation-iteration-count: 2;
  */
  -webkit-animation: pulse 4s alternate 2;
          animation: pulse 4s alternate 2;
  width: 300px;
  height: 100px;
  background: green;
  position: relative;
  margin: 200px auto 0;
  line-height: 100px;
  text-align: center;
  font-family: arial;
}