I had a giant summer squash vine growing out of my compost pile, and I let it go. Within about a month, it was not only producing summer squash but also producing pumpkin-like gourds (some yellow and green, and some white), a few of which grew to gigantic sizes. A gardening friend told me that this is because of hybridization and that the plant can exhibit characteristics of multiple parent plants. It's possible that the parent plant had been crossed with a pumpkin/gourd type plant to take advantage of some of its innate characteristics (disease resistance, etc).
If the weird offspring are really bitter, stop eating them!
You probably won’t die but you’ll be quite miserable. Apparently, once a gourd starts not breeding true, it can revert to a form with way too much bitterness - we humans have trouble with the chemical and get quite sick.
