Blocking in

It can be helpful to divide the creature into head ribcage and hips when you are blocking the creature out.  Principally these are rigid parts of the animal that are flexibly connected- so it gives you something to "hang on to " when you are posing or adding limbs to your creature. Often I'd do the head trace out a spine, add other rigid section as rough volumes- then  put in cross sections, core 'gestures' of limb bones or their volumes and then outer contours of the animal.