Since I had some left over pumpkin material, I decided to use it for the back. I have this pillow already and I was just going to basically take the existing cover off and make a new cover to go on it for Halloween. I just used the existing cover as a pattern to get the size right for my new cover.
The pumpkin material for the back is two pieces and the pillow will just slide into it making it an envelope type back. This is super easy as it requires no zippers or buttons to close it.
Here is the finished pillow! This took me less than 30 minutes to sew (minus the embroidery).