Goats are a species of creature that have existed almost from the original split of the "Perfect" race. Grogar is the most famous goat to have existed, and quite possibly the only one.
The goat civilisation is ancient, even compared to Equestria. About 20,050 years ago, the goat capital city was Tamriel, with its last known king being Grogar. However, he grew greedy and attempted to conquer the world. As a result Tamriel, now known as the city of Shadows colloquially, was banished, supposedly never to return.
After their capital city was seemingly wiped from existence, the goat people became nomads, hoping one day to return to their city, or found a new one. A couple of goats found passage to the floating islands, and started a life there. However, when the islands came crashing down, most did not survive.
During the War of the Three Kingdoms, goats were uneasy allies of the Earth Ponies. Thanks to the supplies given to them by goats, the earth ponies were capable of standing against flight and magic. With the effort of goat and earth pony engineers, the earth pony siege engines were capable of standing against the might of magic and weather. Due their innate magic, earth pony siege engines were more efficient and carried heavier weights than they would normally.
After the Great War, the goat people continued their nomadic existence, rarely straying into Equestrian borders. When the Griffins founded their empire, the goats hid in Equestria's borders and aided the ponies in battle as supply runners. After that, Equestria slowly began to trust the goat people again.
When Nightmare Moon started her coup, the goats sided with Celestia, hoping to profit off of the war. The goat people roamed for a thousand years, developing electronic equipment in the last five years - the type of electronics have been weirdly sporadic. Most goats in the present era have gone to Bitsburg and Stalliongrad, becoming engineers.
Goats are defined by their straggly goatees, and scruffy stature. On average, they are slightly shorter than a pony, and covered in shaggy hair that ranges from grey to black. Occasionally, a goat may be a dark blue or other colour that normally occurs in an Equestrian.
Goat eyes are much narrower than a pony's, and have a unique sideways pupil. Their iris is coloured yellow normally, although there are brown, blue and grey colours as well.
Goats have two horns, that are a sign of magical prowess- the larger the horns, the more powerful the goat's magic.
Goats possess their own, unique magical abilities, known as Bell Magic. Their two horns are two thirds of a magical triangle, that is filled with a bell. While ordinarily metal is a poor focus, the bell instead functions as an amplifier, taking their weak power and then releasing it. While a goat could theoretically do magic without the bell, it is comparable to an untrained, weak foal.
Typically, goats possess skill in electromancy, a school of fire magic that generates electrical current. However, some goats also have a talent for nature magic, similar to earth ponies. Many goats are skilled with metal magic as well, which aids them in the creation of their sporadic electronics. Only a couple of goats possess necromantic abilities, and they typically do not use them at all, for fear of being hunted down by Celestia.
Most goat bells are made with iron, a poor magical conductor but a good amplifier. However, their kings would use a gold or silver bell, which are much better at amplifying and conducting magic.
In terms of strength, goats are weaker than earth ponies in terms of brute force. However, they make up for this by being incredibly agile and sure hoofed, climbing mountains and cliffs with ease. They resist the cold and lightning well, and are fairly durable, although not as durable as an earth pony.
Goats are about as advanced as Equestria, possibly more. They have developed electrical generators that are fueled by leylines, and are key workers in steam buck technology.
Most goats in Equestria prefer not to speak in Equestrian, preferring their guttural language and relying on interpreters. Most can speak in Equestrian, they just don't to annoy ponies.
Goats are primarily focused on ability and function over birthright and form. If their is something unnecessary about their technology, then they remove it. Every single king of the goats had to prove that he is the best in his chosen field, be it magic, technology or warfare. Before the fall of Tamriel, the King would name his heir, which might have been from his own family.
While goats do not believe in any actual god, they do believe that, one day Tamriel will return, and they can reclaim their city from Grogar.