A very appealing character. You did a great job incorporating the different elements in to the design.
One thing that takes away from the image over all is that everything is rendered more or less the same; because the pumpkin, knife, rusty metal, skin, and hair are all shaded similarly, the character looks more like an action figure than an actual living, breathing creature.
Also, the whole image is pretty evenly lit because there are so many light sources with similar brightness. This makes the character seem less spooky/weird/creepy.
Good job on this, though. I'm impressed. =)