Sorry, wrong answer.
This would, in fact, be a large zucchini, a type of squash (Cucurbita pepo) which resembles a cucumber. Zucchini are popular garden vegetables, which grow well in any temperate climate (as the large example illustrated clearly demonstrates). They are low in calories, and are also noted for being an excellent source of calcium, iron, vitamin C, riboflavin, and niacin.
But it's not me.