The model is Kaernus the Vicious from Enigma Miniatures. I'm still in the early stages of learning how to manipulate GS so I don't have many tips, but always keep your tools wet. You can use water, olive oil, vasoline or saliva to keep the GS and tools wet, mostly personal preference. Before starting this guy I learned about mixing 60% GS and 40% Apoxie Sculpt, it's a little easier to work with and when it dries it's halfway between GS's rubbery movable texture and Apoxie Sculpt's rock hard texture.