This website returns an emoji inside an SVG
Use it like /🔥
Some examples
Replace any emoji after '/' to get back your favicon
It works by serving the following SVG
<svg xmlns="http://www.w3.org/2000/svg" width="48" height="48" viewBox="0 0 20 20"/>
<text x="0" y="14">🔥</text> </svg>