I know this is old but to me looks like some type of gourd or maybe a squash, like a cross breed between acorn and scallop type squashes they all cross breed with each other as they are all squash so it's hard to tell.

I know this is old but to me looks like some type of gourd or maybe a squash, like a cross breed between acorn and scallop type squashes they all cross breed with each other as they are all squash so it's hard to tell.

It's tough to say. I have never felt comfortable with eating most volunteer squashes, but it would definitely make a neat autumn decoration!