Nebelung
When Cora Cobb's black shorthair and blue shorthair produced a litter, she was very surprised to find a kitten with medium longhair among them. She named the kitten Siegfried and when the cats produced a second litter containing a black longhair female and a blue longhair female, she chose the blue longhair as a mate for Siegfried and named her Brunhilde. In time these long haired cats were outbred with Russian Blues and soon the breed began to resemble long haired Russian Blues.
This new cat breed was named the Nebelung, which is German for "mist dweller". Even today the CFA does not recognize the Nebelung as an official breed, but they are recognized by the TICA and the WCF. Many cat experts see the Nebelung as a long haired Russian Blue and the Nebelung cat is also judged on the same characteristics at cat shows, except of course for its coat, which should be long. The Nebelung should also have plumy tail, green eyes and a blue coat color. The Nebelung kittens are born with blue eyes which gradually changes into green as they reach maturity.