I started with a NURBS sphere and when it seemed to have gone about as far as I could take it then i switched to polys for details, eyes, ears etc.
This is the most detailed I've ever gotten modeling from a NURBS sphere before.
I plan to model body and head seperately - maybe boots also seperately. It's a lot easier when it comes time to rig.
Check out the subsurfacescattering on my tongue...