crocodile.css

body {
  background-color: #333;
  animation: background 10s infinite;
}

.animals {
  background-color: transparent;
  background-image: url('http://dankmaymays.com/yee/intensifies/yeeyee.gif');
  height: 100%;
  left: 0;
  position: absolute;
  top: 0;
  width: 100%;
  z-index: 100;
  animation: animals 10s linear infinite, move 1s infinite alternate;
}

.wtf {
  background-image: url('https://media.tenor.co/images/4bef07b6e57c9127e899fe330aa33151/tenor.gif');
  width: 300px;
  height: 200px;
}

.wtf-sax {
  background-image: url('http://vignette1.wikia.nocookie.net/mlg-frag/images/0/0f/Epic_sax_guy.gif/revision/latest?cb=20141124020151');
  width: 392px;
  height: 485px;
  position: fixed;
  bottom: 0;
  right: 0;
}

.bad-animals {
  background-image: url('http://dankmaymays.com/yee/intensifies/brightdisappoint.gif');
  height: 100%;
  left: 100px;
  position: absolute;
  top: 100px;
  width: 1000%;
  z-index: 1;
  animation: animals 10s infinite;
}

@keyframes animals {
  0% {
    background-position: 0px 0px, 0px 0px, 0px 0px;
  }
  50% {
    background-position: 500px 500px, 100px 200px, -100px 150px;
  }
  100% {
    background-position: 500px 1000px, 200px 400px, -100px 300px;
  }
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@keyframes move {
  from {
    top: 0;
    left: 0;
  }
  to {
    top: 1000px;
    left: 10px;
  }
}

@keyframes background {
  0% {
    background: white;
  }
  30% {
    background: red;
  }
  100% {
    background: blue;
  }
}