I think that sounds pretty cool, albeit slightly illogical
but hey, logic can take a backseat every once in a while...I suppose what you'd have to do is work your way up the Mumak with greenstuff. I'd start by giving the bottom of their leg greenstuff 'cuffs' and sculpting it to make it look like fur, then, once that's dried, add another cuff that slightly overlaps the previous to give a shaggy effect with the hair getting longer the higher up you go. Keep adding these layers till you reach the top! Do you understand what I mean? Could look for a pic of what I mean by a greenstuff cuff, gimme a sec...
Edit: here's the pic
note the 'cuff' around the troll's arm? I rolled out some GS and wrapped it around his arm, then used a sculpting tool to rake some lines into it to give the effect of fur. You'll need a wet tool for best effects (gosh that sounds dirty) and it helps if you let the GS cure a bit first! This could be a very interesting (and complex) project, I'm excited
