SOURCE

<div class="effect">
  <div class="blackball"></div>
  <div class="redball"></div>
</div>

.effect{
  width:100%;
  height:100%;
  padding-top:8px;
  filter:contrast(10);
  background:#fff;
}
.blackball{
  width:100px;
  height:100px;
  background:black;
  padding:10px;
  border-radius:50%;
  margin:0 auto;
  z-index:1;
  filter:blur(5px);
}
.redball{
  width:60px;
  height:60px;
  background:#f00;
  padding:10px;
  border-radius:50%;
  position:absolute;
  top:30px;
  left:50px;
  z-index:2;
  filter:blur(5px) ;
  animation:rball 6s infinite;
}
@keyframes rball{
  0%,100%{
    left:35px;
    width:60px;
    height:60px;
  }
  4%,54%{
    width:60px;
    height:60px;
  }
  10%,60%{
    width:50px;
    height:70px;
  }
  20%,70%{
    width:60px;
    height:60px;
  }
  34%,90%{
    width:70px;
    height:50px;
  }
  41%{
    width:60px;
    height:60px;
  }
  50%{
    left:calc(100% - 95px);
    width:60px;
    height:60px;
  }
}