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HTML 

              
                <h1><span class="count">0</span> FISH</h1>
<div class="pond"></div>
!

CSS 

              
                @import url(https://fonts.googleapis.com/css?family=Lilita+One);

* { user-select: none; }

html { height: 100%; }

body {
  height: 100%;
  margin: 0;
  overflow: hidden;
  background-color: #1d3f59;
  backface-visibility: hidden;
}

h1 {
  position: absolute;
  top: calc(50% - 125px);
  left: 0;
  right: 0;
  margin: 0;
  padding: 0 20px;
  color: #1d3f59;
  font: 250px/1 'Lilita One', sans-serif;
  white-space: nowrap;
  text-align: right;
  text-shadow: 0 0 80px rgba(255, 255, 255, 0.3);
}

.pond {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(0, 0, 0, 0);
}

.fish {
  position: absolute;
  margin: -15px 0 0 -30px;
  opacity: 0;
  transition: transform 10s;
  animation: spawn .5s forwards;
}
@keyframes spawn {
  100% { opacity: 1; }
}

.fish-bob {
  position: relative;
  margin-top: -20px;
  animation: bob 6s infinite;
}
@keyframes bob {
  50% { transform: translateY(40px); }
}

.fish-direction {
  position: relative;
  transition: transform .5s;
}

.fish-body {
  position: relative;
  margin-left: 10px;
  width: 50px;
  height: 30px;
  border-radius: 50%;
  border-bottom: solid 1px rgba(0, 0, 0, .2);
  transition: transform 2s ease-out;
}
.fish-body::before {
  content: '';
  display: block;
  position: absolute;
  left: -10px;
  width: 0;
  height: 0;
  border-left: solid 25px orange;
  border-top: solid 15px transparent;
  border-bottom: solid 15px transparent;
}
.fish-body::after {
  content: '';
  display: block;
  position: absolute;
  top: 8px;
  left: 34px;
  width: 6px;
  height: 6px;
  background-color: #fff;
  border-radius: 50%;
}

.fish-1 .fish-body { background-color: #d49919; }
.fish-1 .fish-body::before { border-left-color: #d49919; }
.fish-2 .fish-body { background-color: #74a135; }
.fish-2 .fish-body::before { border-left-color: #74a135; }
.fish-3 .fish-body { background-color: #806fad; }
.fish-3 .fish-body::before { border-left-color: #806fad; }
.fish-4 .fish-body { background-color: #d97eb6; }
.fish-4 .fish-body::before { border-left-color: #d97eb6; }

.fish-flip .fish-direction { transform: scaleX(-1); }

.fish-spin .fish-body { transform: rotate(720deg); }

.bubble {
  position: absolute;
  width: 6px;
  height: 6px;
  border: solid 1px #fff;
  border-radius: 50%;
  margin: -15px 0 0 20px;
  transform-origin: center top;
  animation: bubble 4s linear forwards;
}
@keyframes bubble {
  100% {
    transform: translateY(-200px) rotate(-1080deg);
    opacity: 0;
  }
}

.bubble-flip {
  margin-left: -28px;
  animation-name: bubble-flip;
}
@keyframes bubble-flip {
  100% {
    transform: translateY(-200px) rotate(1080deg);
    opacity: 0;
  }
}
!

JS 

              
                var STARTING_FISH_COUNT = 20;

// globals
var $count, $pond, pondWidth, pondHeight;

// on document ready
$(function() {
  // setup
  $count = $('.count');
  $pond = $('.pond');
  determinePondSize();
  
  // events
  $(window).on('resize', determinePondSize);
  $pond.on('click', stirPond);
  
  // fill the pond
  spawnStartingFish();
});

function determinePondSize() {
  pondWidth = $pond.width();
  pondHeight = $pond.height();
}  

function spawnStartingFish() {
  for (var i = 0; i < STARTING_FISH_COUNT; i++) {
    spawnFish(getRandom(pondWidth), getRandom(pondHeight));
  }
}

function stirPond(event) {
  spawnFish(event.clientX, event.clientY);
}

function spawnFish(x, y) {
  // setup fish
  var $fish = $('<div class="fish"><div class="fish-bob"><div class="fish-direction"><div class="fish-body"></div></div></div></div>');
  var colors = [1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 4];
  $fish.addClass('fish-' + colors[Math.floor(getRandom(15))]);
  if (getRandom(2) < 1) {
    $fish.addClass('fish-flip');
  }
  $fish.find('.fish-bob').css('animation-delay', '-' + getRandom(7) + 's');
  $fish.find('.fish-body').on('click', pokeFish.bind(this, $fish));
  positionFish($fish, x, y);
  
  // let fish go
  $pond.append($fish);
  setTimeout(doFishyThings.bind(this, $fish), getRandom(10000))
  $count.text($('.fish').length);
}

function pokeFish($fish) {
  $fish.toggleClass('fish-spin');
  return false;
}

function doFishyThings($fish) {
  blowBubble($fish);
  moveFish($fish);
  
  var timeout = $fish.data('timeout');
  clearTimeout(timeout);
  timeout = setTimeout(doFishyThings.bind(this, $fish), 10000 + getRandom(6000));
  $fish.data('timeout', timeout);
}

function blowBubble($fish) {
  var $bubble = $('<div class="bubble">');
  if ($fish.hasClass('fish-flip')) {
    $bubble.addClass('bubble-flip');
  }

  var x = $fish.data('x');
  var y = $fish.data('y');
  $bubble.css({ top: y + 'px', left: x + 'px' });

  $pond.prepend($bubble);
  setTimeout(popBubble.bind(this, $bubble), 4000);
}

function moveFish($fish) {
  var x = getRandom(pondWidth);
  var y = getRandom(pondHeight);
  
  if (x < $fish.data('x')) {
    $fish.addClass('fish-flip');
  } else {
    $fish.removeClass('fish-flip');
  }
  positionFish($fish, x, y);
}

function positionFish($fish, x, y) {
  $fish
    .css('transform', 'translate(' + x + 'px, ' + y + 'px)')
    .data('x', x)
    .data('y', y); 
}

function popBubble($bubble) {
  $bubble.remove();
}

function getRandom(upper) {
  return Math.random() * upper;
}
!
999px

Console