This is actually just the 'dirty' spot on the bottom of the pumpkin. I added the eyes & mouth to make it a face. The features are carved into, rather than through, the pumpkin.
Notice how pretty & orange the pumpkin is? We chose this one because it was a beautiful rich, dark, green. That may be a good way to pick a pumpkin when you get it near the start of the month. It seems to have hit its peak right in time for Halloween.
Hope you had a Happy Halloween!