Anyone have an idea what this could be? It's a volunteer that came up in the compost pile. It looks like a watermelon but is shaped like a squash or zucchini! This came up from compost made of last year's squash, zucchini, watermelon, cucumber, etc. I'm going to let it grow to see what it becomes but if it is a squash or zucchini I should go ahead and pick it...