Crystal Ponies

Crystal ponies are a new kind of Equestrian ponies that are set to debut in the third season of My Little Pony Friendship is Magic. Crystal ponies are similar to Earth ponies as they lack horns and wings, but are distinct by their shiny, gradient manes and tails, polygonal highlights on their eyes, and, as according to Twilight Sparkle in a preview of an episode, supposed "crystally" coats.

Depiction in the series
As far as a pre-third season preview video reveals, the Crystal ponies have been "gone a thousand years", which explains why they never appeared earlier in the series. They are the local residents of the Crystal Empire, which had been formerly ruled by King Sombra, a time which the Crystal ponies "don't want to remember anything about." Twilight Sparkle mentions King Sombra had unleashed a spell which caused the Crystal ponies to lose the "crystally"-ness of their coats. The Crystal ponies do not recall why they had disappeared in the first place.

According to information provided by Shout! Factory over the upcoming DVD, Adventures in the Crystal Empire, the Crystal ponies "suddenly appeared in the arctic north of Equestria" alongside the Crystal Empire.

According to the previewed season three song, "Ballad of the Crystal Ponies", the Crystal ponies are reputed to have a deep, elaborate culture and history of their own. An event called the Crystal Faire, which Twilight Sparkle and her friends are helping prepare based on a book they found, is being held at some point in the season in order to preserve the Crystal ponies' history, for the sake of the Crystal ponies, whom are being initially supported by Princess Cadance's magic.

Residence
The Crystal ponies have thus far never appeared anywhere else outside their homeland, the Crystal Empire, which has been "gone a thousand years." Certain merchandise state that Princess Cadance and Shining Armor are the current rulers of the Crystal Empire, but neither are Crystal ponies.