chubbs (my 4 year old) and I made treat bags for his class. Eco-friendly too - they are made of brown grocery bags and sewed up the sides. We used scraps of felt leftover from my pillowhead.etsy.com stuff for the spider's bodies, and drew the legs on with marker. The only thing I had to buy was the googly eyes.
My favourite is the triangular spider that he cut out. I had to help with the ovals. Also like the one eyed and three eyed spiders. :)