From w3 schools:
<style>
/* Tooltip container */
.tooltip {
position: relative;
display: inline-block;
border-bottom: 1px dotted black; /* If you want dots under the hoverable text */
}
/* Tooltip text */
.tooltip .tooltiptext {
visibility: hidden;
width: 120px;
background-color: black;
color: #fff;
text-align: center;
padding: 5px 0;
border-radius: 6px;
/* Position the tooltip text - see examples below! */
position: absolute;
z-index: 1;
}
/* Show the tooltip text when you mouse over the tooltip container */
.tooltip:hover .tooltiptext {
visibility: visible;
}
</style>
<div class="tooltip">Hover over me
<img src="/pathtoimage" class="tooltiptext">
</div>
Sounds like about what you want