[JeaS]

Looks like a zucchini to me.

Edit: I take it back… I didn’t see the vine up the steps there… I was going by leaf alone. Did you have a pumpkin on the stairs last fall? I’m going with pumpkin. LOL.

[Herbs4u2]

My daughter thinks the grand dropped pumpkin seeds but those are salted and cooked so …not thinking that’s where it came from. Sure can’t deny it’s “somethin”! I would prefer squash like acorn or winter or zucchini but will be grateful for whatever it is!

[FaithK]

Don’t pumpkins have tendrils opposite the fruit? What a lovely mystery natural hybrid popping up! It looks so much like an 8-ball zucchini, but that vine though! Take one that seems like it’s zuke-ripe, and then let some go to winter-stage, and see what happens.

[Herbs4u2]

It definitely has some serious “tubie grabbies”

[ArtsyAnn]

My pumpkins start out quite round…but it could be a different variety, or another kind of squash. I love mystery squashes. Whatever it is it looks healthy!

[Herbs4u2]

Definitely likes where it is!

[ChiHomestead]

If you used compost that was purchased, the seeds could have been in there or from your own compost or from some friendly birds or rodents.

One year we had this beautiful corn grow up around our house that we didnt plant because of our neighbors bird feeder!

[Herbs4u2]

It’s a fun mystery! No compost. Perhaps a gift from birds I feed!

[bee70]

Your answer is in the stem’s shape. From the looks of the picture provided it isn’t Pepo which is the family of most that we call pumpkins. Also zukes and other summer squashes are Pepo. It looks to be a 5 sided star shape stem attachment. So likely Moschata as Mixta and Maxima are both a “corky looking” fat round stem. Butternut is the most “common” member of the Moschata grown. Have fun and forgive my spelling!

[Herbs4u2]

I figured it out!!!! It’s a round zucchini!!!!

Suppose to pick when the size of a softball….not the size of a pumpkin. Good news? Gonna process the seeds , hoping they are viable. Been told it’s heirloom variety.