A hard-boiled egg is a common, nutritious snack many parts of the world, including the United States. However there is nothing common or typical about balut. While balut appears to be a simple hard-boiled egg, it's center contains more than just yolk. Balut contains a fertilized egg embryo. Balut is prepared by boiling the live embryo, and is eaten from the shell. Depending on the region, balut is seasoned with salt, chili, and/or garlic and vinegar. Balut is widely considered a aphrodisiac, as well as a high-protein and hearty snack. Balut is a popular street food in the Phillipines, and also enjoyed in Laos, Cambodia, and Vietnam. Balut is commonly served with beer.
Balut can be considered bizarre due to the surprise embryo inside the shell. While it is easy to disassociate regular eggs from chickens, balut really brings to attention the fact that you are essentially eating a baby animal. Eating any kind of baby is bizarre to many people, myself included. I would say balut is for people who want to take their standard hard-boiled egg to the next level, and don't mind eating a fertilized duck embryo. :)