My Headcanons

(Note: some of these things are copied from other sources, though it would take too much time to find out where they are.)

Alicorns
Celestia and Luna are the only 'true' alicorns, meaning that they were born with both the horn andnwings. True alicorns are created not by regular means, but by nature: an extremely powerful force or object (in Tia's case, for instance, the sun) releases a piece of pure magical energy, which begins to form a pony.

The reason that the two have such flowy manes is because of excess magic. In essence, their bodies contain so much of it that, if it remained purely in the pony's body, she would probably die from an overload. Thus, it's expelled via their hair - probably the safest and least unusual outlet. Yeah, manes that move on their own are weird enough, but would you rather have constantly sparkling fur? A wisp of magic that flows from their mouth when they speak?

It's nigh-impossible for them to die. They have extremely strong immune systems, and cannot be killed by old age, so the only thing left is being assassinated or something. Of course, it would probably take a whole army of regular ponies stabbing at a true alicorn in order to really pierce their skin, or falling from over a hundred miles above the ground.

If they do, somehow, end up dead, their bodies will simply... evaporate, you could say. They just disappear, and their spirits return to their domains, eternally staying to watch over Equestria/figure out the secrets of the universe/whatever else they wanna do.

And then there are normal alicorns. This term extends to ponies like Twilight or Cadence, who ascended after birth. Though they have extremely powerful wings and flight, they're not as enduring as Celestia, and can be killed, if someone's trying hard enough - but who would? These things aren't known to most of Equestria, and as far as they know, they would just pop up from the dead to murder them in return.

Though Celestia and Luna insist otherwise, there many ponies who worship them as gods.

Dragons
... Okay, fine, so nobody really knows much about dragons. Apart from the fact that they're big and terrifying, they remain largely a mystery. Surprisingly, they are featured in many amateur romance novels - the honourable, misunderstood dragon, who is discriminated against due to his species, meets a beautiful maiden blah blah blah - though this barely offsets the fear most ponies have for them, as there are just as many pieces of media displaying them as villains.

Their diet is... interesting, to say the least. They mainly eat gems, but if they have to, they'll take rocks and metal. This is supplemented by a small amount of meat, often of cattle or pigs. However, there have been reports of dragons rarely snatching up unicorns. (Apparently, their texture isn't as hard as Earth ponies, and pegasi barely have any meat on them.)

It's been said by some that their hoards serve as emergency storage for food, though most doubt this claim. Dragons are known to be reluctant to let any form of harm come to their hoards, let alone eat them. Most would just as soon starve.

Changelings
Changelings are not, in fact, hive minds. It's a common myth - an old ponies' tale. Still, it would be a lie if I said that they didn't think extremely similarly. Their culture doesn't exactly encourage individuality.

In the past, Equestria has attempted to extend a hoof of friendship towards them, perhaps somehow donating love, but always, they declined, attacking the representatives instead. Because of this, neither the princesses nor the citizens are willing to try again, and war against them has even been considered. They appear to think of themselves as intellectually superior to ponies, possibly leading to their hostility and firm declination of any offers of help --- they believe that, if they need the aid of such animals, they've already sunk rock-bottom.

Griffons/Griffins/Gryphons
The preferred spelling is "griffin", but most don't really care about it. While there are certainly griffin scholars, most are less than intellectual. Plus, griffon's also the name of a hunting dog, and they seem to take it as a compliment that ponies compare them to such a strong, loyal creature. (Understandably, ponies are highly confused at this.)

They have a surprisingly strict