The Ayam Cemani breed of chicken. The tongue and inside of its mouth are black, along with its skin and feathers. Gorgeous birds that run about $2500 bucks apiece. Earlier this year (2013) eight hatching eggs sold on Ebay for close to $1400.
Black Copper Marans from My Pet Chicken. They lay the darkest egg we could find: a deep, rich, chocolate brown. For those of you who favor colorful eggs, this breed is a must-have! Marans make wonderful pets, too - they are hardy, calm and quiet, and bear confinement well. They are said to be good foragers without being TOO destructive to your garden.