Hi bud, we use the Geek Gaming Scenics Base Reading bits. This stuff was the pine forest bits in particular www.atomiccards.co.uk/p/ggs-base-ready-pine-forest-ground-cover
Henry says they are "Deezer miniatures cavemen" www.ebay.co.uk/itm/183994850145?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=450sy0yJRgK&sssrc=4429486&ssuid=3la1eif4szu&var=&widget_ver=artemis&media=COPY