The Ayam Cemani is a rare breed of chicken from Indonesia. They have a dominant gene that causes hyperpigmentation (fibromelanosis), making the chicken mostly black, including feathers, beak, and internal organs. The Cemani is a very popular gamecock for cockfighting in Bali because their thighs have much more muscle compared to other chickens, which leads to them being much faster. The meat and eggs are known for their medicinal properties.