JSFiddle - React, Tailwind, and code Playground

HTML

<a class="tooltip" href="http://www.google.com/">
    Google
    <span id="tooltip-span">
        <img alt="" src="http://www.google.com/images/srpr/logo4w.png" />
    </span>
</a>

CSS

.tooltip {
    text-decoration:none;
    position:relative;
}
.tooltip span {
    display:none;
}
.tooltip span img {
    /*float:left;*/
}
.tooltip:hover span {
    display:block;
    position:fixed;
    overflow:hidden;
}

JavaScript

var tooltipSpan = document.getElementById('tooltip-span');

window.onmousemove = function (e) {
    var x = e.clientX,
        y = e.clientY;
    tooltipSpan.style.top = (y + 20) + 'px';
    tooltipSpan.style.left = (x + 20) + 'px';
};