Maybe a chayote squash? Try a search on Google, or the link below.

Here is a link that might be useful: Google: chayote squash

I finally just picked one and tried it. It turned out to be Melothria scabra. Mexican Sour Cuke, Cuca-Melon, variety of names out there. VERY tasty! The cucumber taste gave me better search ideas.

Here is a link that might be useful: Mexican Sour Cukes

I planted a melothria scabra from seed in a medium size pot with ordinary potting soil. I put it in a spot that got sun in the morning and more shade in the after noon. The seedling started off a little slow, but once it began vining it grew very fast since I planted it in July and it is now reaching about 20 ft across a string I put up for it. Most of the first fruits it put out didn't get a start since the male flowers came out way earlier than the fruit bearing ones, but I finally have a cucumber that's over a half an inch long and a lot more little ones following. Can't wait to try them.

I picked my first cucumber today after letting it develope for a couple of weeks. I think they taste excellent, just like a slice of cucumber without having to peel or slice. I'm going to plant this again next spring and use them in a salad.