Squash or gourd?
It is clearly in the squash/gourd family (Curcubita) but it is impossible to say what variety since there are hundreds of varieties and they vary with geography: the system doesn't identify where you are writing from so you could be anywhere in the world. Did you plant seeds and simply lose track of what seed you bought? That happens. I would suggest checking the seed catalogue you used and comparing pictures of what they sell with the shape and size of the fruit that is forming. You can do this online, but checking websites for seed companies in your part of the world and comparing images.
Hello, Glen N.
Thanks for your response. I am in Boquete, Panama - close to the Panama/Costa Rica border. Mountainous terrain, with frequent light rain and temps consistently between 65 and 80 degrees Farenheit. We are renting here and have only been her for about 6 months. This plant sprouted up in the past month or so - since the "rainy season" began.
So, not in the US, and definitely did not purchase any seeds.
Thanks for your time,