Ayam Cemani, the black-hearted chicken

“The bird is inky black from the tip of its comb to the end of its claws, with blue-black skin, jet-black eyes, and a black tongue. It is covered in shimmering metallic black feathers, and even its internal organs are black.”

EVEN ITS INTERNAL ORGANS ARE BLACK

Also its bonnnnnes. Anyway, full article on the breed.