The following are a mix of cotton wool and sponge foilage - sprayed with black primer then drybrushed and with reds / yellows / oranges added for the flame effect.
Not sure which one I like best but the guys at the club liked the 'octopus' (i.e. the one with the smoke arms).
I'll therefore knock out a batch of #2 and #3 and see if I can improve on the look and technique.