Since my basic mesh was seriously basic I decided to refine much more of Grendel's body structure before importing the model into Z-brush. It's nowhere near yet to the 10000 polygon limit but there is still quite a lot of stuff to add.
After this I just done a quick check of how it looks rendered. It's always nice to see something with a bit of shading and smoothing even during the work process. It will be really interesting to see how much it is going to change after proper texturing and Z-brush.