<div></div>

div {
  background: #2db34a;
  border-radius: 50%;
  height: 50px;
  position: absolute;
  width: 50px;

  animation: bounceIn 2s .5s infinite;
}

@keyframes bounceIn {
  0% {
    transform: scale(0.1);
    opacity: 0;
  }
  60% {
    transform: scale(1.2);
    opacity: 1;
  }
  100% {
    transform: scale(1);
  }
}