Looks like slough (shed snake skin by a snake that got bigger and thus needed to peel off its old skin). One of the worst things you can see in places with snakes, since it means there is a likelihood that a snake’s in the vicinity. Happened to one of our workers when I was young ...one of the garden keeps found such a slough in his servant’s quarters ...a few days later he saw a huge snake above his bed. It was at night, and his screams had us all running to see what was up. The snake managed to slither away and escape - for quite some time the man slept with another garden keep until his nerves calmed down. I did not have a good look at the snake, but there were a couple of spitting cobra incidents back then. Might have been harmless, but glossy coils over your bed at night .....hmmmm ....