This Eye of Sauron jack-o'-lantern — or "Pie of Sauron," as its creator refers to it — really gets it right with that spinning eye. It's not a part most of us have sitting around the house, though. That's a "dekatron" counting tube from ye olde times.
Other than that, you just carve up the eye a bit, adds some LED backlighting and — voila! — you've got one angry little pumpkin. It even hisses. Now all it needs is a tower.
You can make your own by following these handy instructions right here.