Can a GIF/JPEG file contain runnable PHP code?

Testing a web application, I can upload GIF/JPEG files and I know there is a possible threat when including PHP Code properly in that GIF/Jpeg (because it is modified using imagecreatetruecolor and imagejpeg).

I was looking for an existing GIF file containing a simple PHP code (like phpinfo or echo 'hello world') just to validate that the threat was concrete.

What would be perfect is a specifically crafted GIF image containing PHP code in the middle OR in the palette color, but I was unsuccessful to find one.