Friend of mine has one... purchased under the name "Xaphoon" or somesuch. It looks rather like a treebranch hollowed out with holes drilled in the branch, and a reed strapped to one end.

However, it sounds dang close to basic sax sound, and it hits the octaves. He's enamored of it, and it's a heck of a conversation starter... "what the heck are you playing?"

M