This is a pattypan squash. We are growing them this year instead of zucchini, because they don't get all overgrown when you're not looking. They're nice to eat, and they can be harvested when they're about 2-1/2 to 3 inches across.
This bad boy is 5 inches across.
I'm SURE it was not on the bush when I checked yesterday.
But I could be wrong.