Nice looking sculpt so far. I like the size of it compared to Grant - looks like it will be relatively small, but vicious.
With the yellow bits... are these small yellow granules (think I remember that happening once - not much you can do about that), or large unmixed lumps from the centre? I always cut thin strips of greenstuff, and then immediately discard the little hard middle bit. Possibly this indicates that my green stuff is a bit old, but it does save having to work around the unmixed bit!