CSS code

.side a[href="#OuchCharlie"]::after {
    content: "";
    display:block;
    width: 120px;
    height: 176px;
    background-image: url(%%dropsygif%%)
    animation: sidebarimage 7s steps(4) infinite;
    -webkit-animation: sidebarimage 7s steps(4) infinite;
    -moz-animation: sidebarimage 7s steps(4) infinite;
    -o-animation: sidebarimage 7s steps(4) infinite;
    -ms-animation: sidebarimage 7s steps(4) infinite;
}

@keyframes sidebarimage {
from { background-position: 0px 0px; }
  to { background-position: 0px -704px; }
}

@-ms-keyframes sidebarimage {
from { background-position: 0px 0px; }
  to { background-position: 0px -704px; }
}

@-o-keyframes sidebarimage {
from { background-position: 0px 0px; }
  to { background-position: -3720px 0px; }
}

@-moz-keyframes sidebarimage {
from { background-position: 0px 0px; }
  to { background-position: 0px -704px; }
}

@-webkit-keyframes sidebarimage {
from { background-position: 0px 0px; }
  to { background-position: 0px -704px; }
}