This gourd is popular in Southern India and Southeast Asia. It comes in various colors, sizes and shapes, growing to as long as 6 feet, and in Asia is often seen with a rock tied to the tip to keep it growing straight. Shoots and leaves are also eaten as a vegetable.
The flesh of this gourd is similar to the Luffa and Bottle Gourd and like them will hold its shape when cooked. Unlike the other two, the seed mass of the Snake Gourd is loose and fluffy. It is removed from all except the long 1 inch variety shown below. Snake gourd is also used in traditional Chinese medicine. Photo by Abhilash placed in public domain.
The Snake Gourd has a very strange flower that opens at night. In the photo the flower is still unfurling so it looks disorderly but it will open to 5 lacy petals. Photo by Tanakawho distributed under Creative Commons Attribution 2.0
Buying: These are still a "hit or miss" item here in Los Angeles, so you buy them when you can get them. They are most often found in Indian markets and can cost as much as US $2.99 / pound there. When they show up in one of the regular produce markets they can be as low as $0.79 / pound. They are very light weight.
Cooking: Snake gourds have very thin skins and are rarely peeled. The seed mass is very loose and spongy, generally removed (except perhaps in the thin snaky ones shown below). There are recipes that use the seed mass separately from the gourds. Like other gourds, and unlike squash, the flesh becomes tender with cooking but does not become mushy, holding its shape well.
More on edible Gourds.
Here are some really snaky ones from a local Indian market in Los Angeles,
purchased in early 2010. The longest was 33-1/2 inches long, 1.1 inches
diameter and weighed 8 ounces.
Here's yet another variety from the same Indian market about 2 years earlier.
These were about 20 inches long, 2-1/4 inches diameter and weighed 1 pound
4 ounces. Green and white striped ones as shown in the heading photo are
also common here.