To make this costume I purchased two pumpkins. One slightly lager than my head and another larger than my waist. For the hat: I cut out a hole the size of my head, cleaned out the stringy bits and seeds and wore it. For the "pants" I cut a hole through one side of the pumpkin and out the other, removed the gunk and put it on.
Step 2: Repairs and Duration
The large pumpkin split as soon as I started moving so I added laces to one side. Originally I thought that I would have to make suspenders, but the laces allowed me to tighten the pumpkin enough that it would stay on. The costume lasted in this state for over two hours, but split into several pieces when I swung over zealously at the pinata. I spent the rest of the night just wearing the hat.
Step 3: Leftovers
This is the only costume I have ever made where we ate the excess material. We made pumpkin soup, pumpkin pie filling, pumpkin bread, and spicy toasted pumpkin seeds.