Squash paternity

OK - so pretty sure some squash got lucky over the summer. But who was it? In early summer, I planted acorn squash, butternut squash, and pumpkin. Winter beets and carrots were planted in August with a lot of our home grown compost, and what to my wondering eyes would appear? In addition to the volunteer tomatoes, four squash plants grew. Apparently if pollen is spread, the original generation (summer in my case) looks fine, but the next generation would show the change. Two of the volunteer squashes look like regular acorn squashes, but two are crazy squid squash. So what plants do you think mated to make the goofy squid squash?