Fire that spreads through mobs

Hello, I would like to make burning mobs let make fires where they are stepping on(only on burnable surfaces of course). Also they should light other mobs if they are touching them. They should melt near snow and ice and emit some light(just like a fire). Optional: let burning creepers spread their fire at explosion (napalm bomb ).

I hope that someone will do it.

Edit: Whoops. Wrong section. Could someone move it to requests?