From what I read somewhere the shape of the cromach head has a purpose. The opening would be the right size for a sheeps neck making it easy for the shepard to control the sheep. And the little upturn (which is now mostly a carved thistle) has a purpose as well. If one of the sheep was giving birth, then the shepard could stick the staff in the ground and then hang a lantern from the upturn. This would leave both of his hands free to assist in the birthing. It makes sense, but it could just be a romantic legend.

I want to say that most Scottish made cromachs are made of hawthorne for the staff and a rams horn for the head. But I suppose it could be made from a shaped piece of wood as well.

I don't know if a market stick is considered a cromach. It has a much smaller opening in the head. This is used to grab the sheep by the leg.