my brother in law has a potato farm, but unfortunately he just sold out of last years crop... luckily they have 8 Hens.
but years ago, when my nephew was little ( he's 23 now), my Sister, instead of buying and Carving Pumpkins each fall, found a few big, roughly pumpkin sized/shaped Field Stones, and painted them Orange. then each October she and the Kid(s) would draw faces on them with black Sharpie, which would fade away by the following October....