Autumn Blaze here is a Kirin, an ancient species of pony-like creatures that inhabit the far corners of Equestria. As we have seen in the show, most Kirins will live in small, close-knit communities under the leadership of another kirin, like Rain Shine. When a town starts getting crowded, the son or daughter of the leader will branch off, leaving their home in search of a new place to live and bringing several other kirins with them. The spots kirin choose to populate are often hidden in plain sight, and are well protected from the elements and intruding creatures.
 
Legends once described the kirin race as a hybrid of sorts between pony and dragonkind - this is, of course, untrue, but that doesn’t stop most tall tales about them. They do prefer to live their lives unbothered by the outside world, after all. Not much is known about them outside of a few who left their villages and some old accounts by pony explorers. Kirin are another species closely related to ponies, but still have many traits that set them apart from their equine brethren.
 
They are fireproof, naturally - wouldn’t want to burn alive whenever your anger gets the best of you - although often their homes are not, which can be a hazard. All kirins are born with traits often associated with unicorns of old: Lion-like tails, cloven hooves, and silky hair covering their bodies. Unlike ponies, however, kirin can never be born without a horn or with wings, unless they have a child with a pony that has those traits (like Aurous Idol). They all have cat-like pupils, scale-covered backs, and large manes. Their large, branching horns are said to give Kirins a special connection to nature and the world around them, similar to earth ponies. Compared to common ponies, their colors are more muted and earth-toned, allowing them to seamlessly blend in with their surroundings.
 
 
Kirins - as individuals and as a people - try their best to live their lives in harmony. An important part of their culture is striving to find balance within themselves, in their community, and in nature. This is where their Nirek forms arise - if their is an imbalance in an individual’s emotions, particularly bad ones, their form is consumed with the negative energies and transforms them. Rain Shine is a relatively recent ruler, and for a while she and her kirins were on a steady downward spiral. That one argument in the marketplace didn’t directly cause everyone’s anger to jump out of nowhere - It simply tipped it to the breaking point. And so, Rain decided that silencing herself and the village was the easiest way to avoid any more destructive disasters.
 

 
Autumn specifically:
 
After being visited by Fluttershy and Applejack, and getting helped by them, Autumn Blaze was overjoyed! Her town was finally back to the way it used to be…but, she was itching to see some of the outside world. After some heartfelt “see you later”s and packing a couple bags, Autumn set off to explore the jungle surrounding her home. During her travels, she happened upon a fellow explorer - a pony who went by the name Daring Do. The pegasus reluctantly let the kirin travel with her for a while. Autumn was a little put down by Daring’s serious attitude. But, after dodging perilous traps, escaping the goons of Dr. Caballeron, and putting a priceless artifact back where it belonged, the two mares had bonded, impressed by the other’s skills.
 

 
Other species headcanons:  
Hippogriffs | Thorax / Changelings