This warg on top has a scar running through the eye (although it doesn't show up so well in the exposure from this photo) so I painted this as a blind eye.
For the rocks on the base, I broke up some chips of bark. I think they do nicely as rocks after you get them painted.
I got a hand drill not to long ago (you can see it here: http://www.games-workshop.com/gws/catalog/productDetail.jsp?catId=cat470006a&prodId=prod1095460). These wargs are a real pain to attach to the base with just glue. Now that I have the drill I will probably insert a wire into the leg and down into the base to better hold it. Also, you can see that with the one warg, the rock is strategically placed to balance the weight of model, but still give the allusion that he is jumping over the rock.