I finished the unit of Killa kans with custom grotzookas today. I added smoke to the exhaust stacks for a little extra fun. These are really easy to make, all you need is super glue, modeling 'clump' and wire. Simply cut a length of wire to the size you want the smoke then thread on balls of clump. The clump balls need to start small and progressively get larger. This creates the bellowing effect.