Like durian, the elephant apple (or wood apple)* has a strong odor, and is a favorite of elephants, thus the reason for its name. It is enjoyed by many people in the non-western world.
Elephant apple trees are native to Indonesia and also found in India, Sri Lanka, China, Vietnam, Thailand, and Malaysia. Trees grow to around 25 feet. The fruit has been compared to an unripe apple in taste and has a wood-like shell that must be cracked to open.
Nutritionally, it is a good source of phosphorus and vitamin C, and even contains calcium. In India in particular the elephant apple has been used for centuries for various cures, as treatment for nervousness, stomach upsets, fatigue, dandruff, and hair shedding. Other sources cite anti-diabetic, antimicrobial, and anti-inflammatory properties.
Elephant apple is used in curries, chutneys, and beverages. It is also used to make pickled condiments and jellies.
(Don't miss this. He convinced me it's really good!)
*Note: Many online sites refer to this fruit as either elephant or wood apple, as one and the same apple. But they really are two different apples, according to one site, so I add this qualifier. Wood apples are mostly found in Thailand, Malaysia, Cambodia, and India and have a different taste (as in video). Elephant apples are much tarter when fresh and have apple-like flesh and color (see recipe video).