So sorry it's not a real pumpkin. This one's made from a foam pumpkin that was given to me to carve for the annual carnival at my son's school. I use the same process for carving real pumpkins:
1) Draw an image onto a piece of paper that will fit on the pumpkin
2) Tape the image on the pumpkin
3) Use a thumbtack to puncture small holes along the lines to be carved
4) Remove paper and carve (I use a knife specifically for pumpkin-carving -- got it at the craft store)
5) Make a hole at the bottom of the pumpkin to fit an LED light (also purchased at the craft store)
6) Lastly, clean up. Have a vacuum cleaner handy. This was my first time carving foam, and there was a lot of debris. Actually, I was thinking I should have worn a mask because the serrated knife makes a lot of dust.
Here's a rough stencil that can be used. Areas marked in red are where the pumpkin should be carved out.