Not a Banana squash, and does look like a squash but I have no idea which. Could be a Pink Banana cross pollinated with some other type. Can't see the stem to verify whether it is indeed a C. pepo or C. maxima

Whatever it is, its certainly cool-looking.

That is awesome, I would buy a lot of those if I saw them in a store! How big is it, maybe like a foot across? That is one reason I love growing squash, you can get some really astounding hybrids. Please post more pictures as the season progresses! Were the seeds traded or did you buy seeds from a reputable company and end up with that?

This seed is like 5 yrs old(methinks?), from a trade. I finnally remembered it and planted the one seed leftover.
So when do I pick this THING?
About 9" across.

Since its obviously a winter squash it should probably be left on the vine until the shell is hard -- possibly until the vines die naturally from the first touch of frost.

Uhm, what about the stem id's the plant? I have a volunteer that has a thing on it, too. I had thought it was a misplaced Lumina pumpkin, but it's not.