Surprisingly enough, a prickly pear is not a pear, but the fruit of a prickly pear cactus. This fruit, also known as tuna in Spanish, grows on the tops of a mature cactus plant and comes in colors ranging from deep red, yellow, and pale green. The fruit can be eaten raw, minus the outer skin, and is best served chilled. The flavor is mild and sweet, and has been called nature's bubblegum because of its taste.