Father Oak for my own Pulp City collection (click for link).
The technique involved painting a grey-brown base coat, and then two lighter quick dry brush coats, with some olive green dry brushed to bark edges. This was followed by painting some but not all vines olive green. Then I applied a very thinned down wash of Gryphonne Sepia, followed by Soft Tone, then Devlan Mud. Finally I picked out some edge highlights with VMC Stone Grey, and painted the eyes and mouth. All told, maybe an hour and a half over 3 sittings. It is no award winner, and maybe a little lighter in colour than is preferable, but I am happy with how it turned out, especially to get it finished so quickly with recently losing my painting momentum.