Repeat the procedure for the rear paws. Make a nice and round belly using the Clay brush. Also add folds at the places where the skin is compressed. At this stage we have blocked the main form. We will now start detailing (Fig.23).
Subdivide the geometry once more and keep refining the details (Fig.24). Try to put the maximum detail that each subdivision allows and only subdivide it when the mesh does not have enough resolution to support more detail. At this subdivision level, using the Clay and Move brushes, I have added some more skin folds, knuckles on the fingers and a clearer shape to the snout and lips. I have also marked the limit of the shell that covers the head.
Subdivide the body once more. In order to create the tail rings, hold Ctrl and change the mask selection mode to Rect (Fig.25). Still holding Ctrl, click on the brush alpha and select the "Alpha 27" from the list (rectangular gradient). Holding Ctrl go to the Alpha menu and press Rotate to rotate the gradient 90 degrees clockwise.
Now, when you create a mask, you will create a rectangular gradient. Make sure you are on a side view. Mask the base of the tail and invert the mask selection (Press Crtl and click on the background). Press Ctrl + Alt to subtract to the mask and mask all the rings of the tail. From the Tool menu, under Deformation, increase the Inflat slider to 8 and then the rings will be created. You can then discard the mask (Fig.26).
Subdivide the body twice more (you should have a total of six subdivision levels). Smooth the tail rings, add a bit of volume to the edge and use the Pinch brush to sharpen the ring's edges (Fig.27). Start sharpening all the details using the mPolish and Pinch brushes. Notice how I have refined the head shell by using the Pinch brush at the borders.