Who knew? Some chickens are black all the way though

Here's a bit of an oddity. Some breeds of chicken are hyperpigmented, due to a condition known scientifically as fibromelanosis.
What this means is that the Ayam Cemani chicken of Indonesia is a deep bluish-black colour. But not just the plumage is black, so is the skin, beak, comb, tongue, and toes. Even its bones are black, and its meat is also black-tinged. A few other breeds also exhibit this kind of dermal hyperpigmentation, including the Silkie chicken of China, the Black Hmong chicken of Vietnam, and the Svarthöna chicken of Sweden, although not quite to the extent of the cemani.
Apparently, this rare genetic mutation can be traced back to just one individual bird, hundreds or even thousands of years ago. The strange colouration has not done these birds much harm though. They enjoy normal chicken lives and health, and have even become popular with show breeders and, predictably, with gourmands, who maintain that the off-color meat and bones have a distinctive and rich flavour.