from wiki:
A Balut (Trứng vịt lộn or Hột vịt lộn in Vietnamese, Pong tea khon in Cambodian) is a fertilized duck (or chicken) egg with a nearly-developed embryo inside that is boiled and eaten in the shell. They are considered delicacies of Asia and especially the Philippines, Cambodia, and Vietnam. Popularly believed to be an aphrodisiac and considered a high-protein, hearty snack, balut are mostly sold by street vendors at night in the regions where they are available. They are often served with beer. The Filipino and Malay word balut (balot) roughly translates can also mean "wrapped" depending on pronunciation.
nope, never had it. most likely never will.