African whatsit spear for identification

[Cthulhu]

Clearly meant to be some sort of mancatcher, though the central blade makes the person caught somewhat dead as well.
The leather below the lumpy gray materal looks African to me as well.
But the lumpy gray material, what is it? It looks cleaner than the rest. Could this be some sort of fantastical composite? I've certainly never seen anything quite like it.