Custom Image Shapes
Use Adobe Illustrator to make SVG file and copy its code. File > Export > Export for Screens.
Note: SVG code must be a single path, the data-svg-const-width and data-svg-const-height attributes is the original size of the SVG graphics, data-img-width attribute is wanted the size of the displayed image which it cannot be smaller than the width of the SVG.
<svg fill-rule="evenodd" clip-rule="evenodd" width="300px" height="300px"
viewBox="0 0 300 300">
<path fill="#191616" d="M105.1,18.4l154.2,184.3C259.3,202.7,49.7,208.7,105.1,18.4z"/>
</svg>
