Century Egg

Description
There is a method of preserving eggs, developed in faraway Khitai. The details vary among the people, but this method often involves clay or ash or salt or quicklime. The egg, so preserved, turns to a dark green. Those foreign to the practice often only eat such an egg out of desperation or a drunken dare. There is the chance that the one who preserved it did not use the ancient method precisely. An imperfectly preserved egg might bring terrible sickness to the eater.