floating image

<style>
.image {
    animation-name: floating;
    animation-duration: 3s;
    animation-iteration-count: infinite;
    animation-timing-function: ease-in-out;
}

@keyframes floating {
    0% { transform: translate(0,  0px); }
    50%  { transform: translate(0, 15px); }
    100%   { transform: translate(0, -0px); }
}

</style>

<img src="https://64.media.tumblr.com/af0ba9cfc8ec4fce0371acc3f2a5fb5d/8c436493c1c20170-f4/s540x810/b408af581d440ddc4b72833f25095f4b1b926bef.jpg
" class="image" style="width: 30%">