Kirin

The Kirin are a breed of ponies who, like s, possess magical abilities, but can also transform into fiery Nirik when angered.

History
The origins of the Kirin are a mystery, but they are known to have resided among the Peaks of Peril as far back as the time of Rockhoof. The Kirin were "known for their kindness and truth-speaking", but outside groups were unaware that they were the same beings as the Nirki also known to inhabit the region. Perhaps due to their isolation, the Kirin were largely forgotten by or unknown to the denizens of Equestria, with only an ancient shield with their legend inscribed on it reflecting their existence.

At some point, the village in Kirin Grove was destroyed when a quarrel between two Kirin escalated to include the entire village, who all became Nirik. After their anger had subsided, their leader Rain Shine decided that words and the emotions they provoked were a danger, and led her people in entering the nearby Stream of Silence. This magical body of water took the power of speech from the Kirin, as well as leaving them with few if any emotions. However, the Kirin Autumn Blaze eventually became frustrated with the inability to express herself, and discovered that she could create an antidote using foal's-breath flowers. The other Kirin were quickly frustrated by her incessant vocalizations, and Rain Shine ordered her to either enter the stream again or leave the village.

Choosing the latter, Autumn Blaze spent some time in isolation before and  arrived in the area on a mission from the Cutie Map. After speaking with Autumn, Applejack became convinced that they should help all the Kirin speak again, but Fluttershy opposed this. Their argument nearly prompted the others to immerse them in the Stream of Silence, until Autumn used her Nirik form to stop them. Her realization that feelings were not of themselves evil, but simply had to be handled correctly, moved the other Kirin to repent of their vow of silence. After Applejack and Fluttershy located more of the flowers needed for the cure, the Kirin regained their power of speech.

Characteristics
All Kirin seen have large horns emerging from their foreheads, which curve backwards rather than sticking straight out like many Unicorn horns. It is common for these horns to have smaller branches coming off of them. The horns of all Kirin thus far seen are red-similar to Sombra's Unicorn horn-and come in various shades, and are often marked by stripes or other patterns of a lighter shade. Much of the body of a Kirin is covered in fur similar to that of most other pony breeds, with the exception of their cloven hooves, backs, and foreheads. The latter are covered with reptilian scales, which the hoofs will match in color.

Kirin have long, thin tails, and the hair that grows from them is thicker than seen on most other ponies; their manes are similar, with some resembling the manes of Lions. Their ears are also larger and more cupped than typical pony ears, and the top tips are always darker than their usual fur. The fur on their front legs also grows longer than that of typical ponies.

Residence
All known Kirin live in the Kirin Grove, surrounded by the Peaks of Peril, on Dragon-Kirin island.

Powers
Like Unicorns, Kirin possess magic that allows them to move objects; the patterns on their horns will light up when it is in use, with the aura of the horn and around the object or creature being moved depending on the individual. When angered, Kirin undergo a transformation into Kirin, which causes their fur becomes black, their scales gray, and their manes and tails become fire. Fire also streams from their eyes, which becomes white, and hooves, and becomes larger and more intense the angrier the Nirik in question becomes. All seen Nirik have the same curved horn, as opposed to the unique horns of the various Kirin.

Trivia
Long before the introduction of the Kirin, in the episode, briefly assumed a form with some similarities to the Nirik, with her mane and tail becoming fire and her eyes and coat changing color. This form, like the Nirik, was caused by Twilight becoming angry; however, Twilight only took it once, and it was presumably more for comedic effect than to be taken seriously as a transformation.