Plant sprouted after a particularly wet spell towards the end of July. Hasn't been growing long. Was covered in flowers that just dropped. We noticed the "growth" after cutting a field yesterday. I'll try to take a better pic with something in it for scale. It is definitely watermelon/zucchini shaped, more cylindrical than round. It's over a foot long and has some girth to it as well. I don't recognize the leaves.
I had a volunteer heirloom tomato plant last year at the edge of a field/treeline, very beefstake like, large tomatoes, meaty and slightly juicy. I built a cage for it out of scrap field fence, never messed with it except to harvest tomatoes. Made great tomato sandwiches on hard bread with a little olive oil, salt, pepper, garlic and leaf lettuce. Some of the best tomatoes I've had in years. Tried to save seeds and cultivate this year, no luck .
More pics, its a little more than 12" long, approx. 25" around an rolled over a little, a bit orange/yellow where resting on the ground. Thanks to my neighbor for talking the pics and sending them to me.
County Fair is this weekend. If we weren't so busy showing my daughters Boer goats, maybe I could enter the mystery vegetable in the produce contest. Strange coincidence, the original "Invasion of the Body Snatchers", was on Direct TV while we were hanging out waiting for the goat judging this evening. One of my all time favorite 50's SciFi/Horror movies. Maybe we are growing pods . Better check the basement when we get home.