Just a short length of rope, and stick walking stick is fine if you use one, keep the rope short so that you actually lift the head clear of the ground when dragging, makes it a lot easier.
If hill stalking be very careful about using any sort of harness, as on steep ground the beast can take off and end up dragging you with it, which can and has caused serious injury especially with stags where you can become impaled on an antler,far better to use a short rope or piece of webbing that you can quickly let go of.