Silvery blue, exotic-looking, and with emerald eyes, the Nebelung is quite an eye-catching and somewhat mesmerizing cat. It is most quickly described as “a longhaired Russian Blue,” except it is not a Russian Blue – the first recorded Nebelung didn’t have a direct Russian Blue ancestor.
The parents of the first Nebelung were actually a domestic shorthaired cat (that looked like a Russian Blue, but wasn’t) and a black longhaired Angora-like sire.  The two produced a litter that included a beautiful blue longhaired male kitten, who was later named Siegfried. After several months, a second litter was born to the couple, and again, a longhaired blue kit appeared; but this time, it was female, and she was named Brunhilde.
The two longhaired blues were mated, and a new breed was on its way – but what should the breeders call it?
If you paid attention in literature class, you would know that Siegfried and Brünhild were legendary characters from an ancient German epic poem: The Song of the Nibelung (or, if you want to keep to the original language, you can instead say, “Nibelungenlied”).
And so the new breed that began with the cats named Siegfried and Brunhild was called Nebelung. In order to help the new breed develop, the Russian Blue was allowed as an outcross.
A Nebelung is defined by its color – a mandatory blue with silver tips – and its long hair. Its tail is thick and plumed. Its eyes are green and wide set. Its ears are large. 
Like the story after which their breed was named, the Nebelung cats have a mythical, mystical air. Although they are generally good natured and affectionate, they are also regal and reserved, especially among strangers. The Nebelung is not the type of cat that would roughhouse with your kids. In fact, it might not like your kids very much, if they’re the highly active type who love to chatter and play. This is a cat that prefers peace and quiet, with just one or two gentle and soft-voiced humans to love. 
It is important that the Nebelung’s humans should love to groom cats. The Nebelung, with its longhaired coat, needs daily combing; otherwise, it will end up a hopeless mass of mats. Aside from that, this breed only needs the usual tooth brushing, nail clipping, and ear cleaning that other cats need as well. The Nebelung has no breed-specific health issues and, with proper care, is known to live beyond 16 years. 
 Cats 101: Nebelung. Animal Planet. https://www.animalplanet.com/tv-shows/cats-101/videos/nebelung.htm
 Nebelung. The International Cat Association. https://www.tica.org/cat-breeds/item/242
 Nebelung. Wikipedia. https://en.wikipedia.org/wiki/Nebelung