Cucumis metuliferus, horned melon or kiwano, also called African horned cucumber

[ Pic is for reference purpose only . . .]
Cucumis metuliferus, horned melon or kiwano, also called African horned cucumber or melon, jelly melon, hedged gourd, or melano, is an annual vine in the cucumber and melon family.
When ripe, it has a yellow-orange skin and a lime green, jelly-like flesh with a tart taste, and texture similar to a cucumber. The horned melon is native to Africa, and it is now grown in California, Mississippi, Chile, Australia and New Zealand, as well.
Some more info . . . African horned cucumber
When it is exported to the U.S., the horned cucumber is often labeled as "blowfish fruit." With its spiky yellow exterior and juicy green interior, this is one fruit with vibrant contrasts. It tastes like a cross between a cucumber and 
a zucchini, and it is rich in both vitamin C and fiber. Native to Africa, it has been exported and cultivated as far away as New Zealand, Australia and Chile.