Simple static prop did this a couple years ago, so poorly graphically documented.
You'll need 16 3' sections of one inch pvc, 8 6" pieces, 8 90deg elbows, and 8 45deg elbows.
You can see from the pic how it's assembeled the 6" sections are shoved into the ground to support the legs, the pumpkin is just set on top, with a smaller carved pumpkin used as a head.
Step 1: Add Darkness and a Candle
And you are done