The
Kiwano (aka, the Horned Melon, melano, African horned cucumber,

jelly melon, hedged gourd, or English tomato) is a fruit native to a region of the Kalahari Desert. When picked green and allowed to ripen, the fruit tastes like a mix of cucumber and kiwifruit. When it's picked fully ripe, it has a banana-like taste. Here's some help from
wikiHow.