its a mutant. your pumpkin before could have been pollinated from a squash and now this is the offspring.

Thanks for that info, Terrybull. I never knew that could happen. I guess I thought if a pumpkin flower didn't get pollinated by a pumpkin flower, there would be no pumpkin. Kind of like a dog mating with a cat.

It is an ornamental gourd. Not good for eating. Most orange pumpkins, a lot of summer squash and ornamental gourds (the small colorful ones) are all the same species and interbreed freely.

Incidentally, pumpkins are squash and vice versa. The C pepo species has varieties that produce Zucchini and Sugar Pie pumpkins. There is no biological difference between them except some selective characteristics such as calling most orange ones pumpkins.

I hate short vined zuchini plants, so what if I interbred a zuchini with a pumpkin vine. Would the fruit be edible and the vine long? Or cucumbers with massive leaves? Actually cucumbers are different I think.

All C. pepos cross breed readily, This group contains both vining and bush varieties and includes crooknecks, straight necks, scallops, zuchini (bush); winter squash; Delicata, Spaghetti, some pumpkins, and small ornamental gourds. The crosses are unpredictable for the most part, but you can get some interesting plants.

Mmmmmm... spaghetti squash pie that tastes like pumpkin maybe?