an autorigger like mGear or Advanced Skeleton + an afternoon of weight painting using ngSkinTools will get you comparable rigs to what's been shown. The trickiest thing to rig is the face (either joint or blendshape based) and or get a full sim muscle setup going. Neither of these are shown.
For something low poly, stylized and simple like the fox that is shown it's no time at all with current tooling.