At first glance, these strange, dark, horn-shaped objects might look like something from another planet—but they’re actually water caltrops, also known as bat nuts, devil pods, or buffalo nuts. They are the hard fruits of an aquatic floating plant from the Trapa family, and their unusual shape is what makes them so fascinating.

The outside is dark, woody, and extremely hard, with several sharp points that can resemble little bats or animal heads. But inside is a completely different story: once opened, the fruit contains a white, starchy kernel. Its flavor is often compared to a combination of chestnut, sweet potato, or mild water chestnut, making it a popular food in some parts of Asia.

If you ever come across them, don’t eat them raw. Because they grow in water, they should be cooked thoroughly before eating. A common preparation is to boil them in water for around 20–30 minutes, allowing the inside to become tender. After they cool slightly, the tough shell can be cracked open with a nutcracker or another suitable tool.

Once the shell is removed, the soft white kernel inside is ready to eat. Their strange appearance may make them look intimidating, but water caltrops have been eaten for centuries and are valued as a nutritious, starchy food. Would you have guessed that these bizarre-looking “nuts” are actually edible? 👀