I don't know what you would call this. A diorama, a shadow box?
But what ever you call it, I re-e-a-a-lly like it.
And this is how I made it. I took a carvable foam pumpkin and sawed out an opening with a steak knife.
Then I found out that the inside of the pumpkin had impressions from the molding process that didn't look good so I mod podged newspaper over it.
Then I taped it off, covered it with plastic and gave it two good coats of matte black spray paint.