JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <img src="http://jonamdall.files.wordpress.com/2011/06/small-nyan-cat11.gif" />
    <span>This is cat!</span>
</div>

CSS

#wrapper span {
    visibility:hidden;
    position:absolute;
    left: 50px;
    top: 70px;
}

#wrapper:hover span {
    visibility:visible;
}

#wrapper:hover img {
    opacity: 0.4;
    filter: alpha(opacity=40); /* For IE8 and earlier */
}