Visually, I wanted to create a jack-o-lantern effect with the skull. Instead of the skull burning up and around itself, I wanted it to burn from the inside out. It took a lot of experimenting to emulate the glowing ember effect but I'm very pleased of the way it turned out.
Skull image: http://rustymermaid-stock.deviantart.com/art/Skull-Stock-113787014
copyright 2011 Kiren In Digital