Animate Fire (drawing)

OK, I’ve got a guy who wants me to animate the fire at the bottom of his website , yeah I know its not a great website ATM, but we can’t change much of the stuff yet, except for the main pictures, cause its about to be put in an advertisement and we don’t have any time,

The problem being, How would I go about animating that fire? I mean, what would be the fastest, and neatest way. I tried using liquify in photoshop 7, but it was very time consuming and looked sloppy, does anyone have any ideas? I’m fresh out, and open to any suggestions :beam: