Pirates vs. Ninjas? Fluttershy is best pony? Pikachu is overrated? All arguments are acknowledged and discussed here.
When I wrote MLP: Friendship is Magic Pony Types, My Little Pony: Friendship is Magic may not have been new, but it was a very good cartoon with a very unique cast of characters. Now, as of October 12, 2019, My Little Pony: Friendship is Magic has officially ended. But even if this show has ended, that does not mean one has to forget about this show. Mostly because the characters of My Little Pony: Friendship is Magic was able to make a show that not only appealed to children, but also older audiences as well by making the cast and characters memorable or unique to previous entries to the My Little Pony franchise. Usually by introducing an entirely new species of pony that was based on mythological creatures or whatever newly introduced environment gets made in My Little Pony: Friendship is Magic. Here were even more interesting Ponies that were introduced during this show's airtime.
I talked a little bit about Princess Cadence in MLP: Friendship is Magic Pony Types. As an Alicorn princess who was set to be engaged to Twilight Sparkle's newly introduced brother Shining Armor in Canterlot, one plot point was that the wedding had to be guarded against enemies. And these enemies came in the form of Changelings.
Looking like insects, the Changelings were shown to have one fascinating ability. Shape-shifting. In fact, a plot point in A Canterlot Wedding: Part 2 was that Queen Chrysalis turned into Cadence so that she could impersonate Cadence and marry Shining Armor. Mostly to feed on the love that Shining Armor had for Cadence. Which ironically is what defeats Chrysalis in her introductory episode.
Another aspect about Changelings was that they fed mostly on the love that came from other living lifeforms. This meant that Changelings had to change into others to infiltrate societies. This changes in later episodes.
Thorax was introduced in the Season 6 episode The Times They Are a Changeling as a Changeling who wanted to make friends with other ponies. Which resulted in Thorax staying in the Crystal Empire to better learn how to make friends. Presumably looking like a regular pony, of course. He later appears in To Where and Back Again: Part 1 with a slightly different look. Which results in a full metamorphosis in To Where and Back Again: Part 2. Along with a promotion as the new leader of the Changelings once Chrysalis was defeated.
Now lacking the holed legs and darker aesthetics of their original forms, Changelings did not need to feed on the love of other beings. Mostly because this change came from the realization that Changelings could get just as much energy by giving love to others. Or friendship. Their bodies emphasized their more insectoid natures as well. They still retain their shape shifting abilities, too.
In the episode To Change a Changeling it was shown that the change from one form of Changeling into another involved realizing a strong form of love for something. In the case of Thorax's brother Pharynx, that love came in the form of the Hive itself.
Appearing in the third season premier The Crystal Empire, the Crystal Ponies served as the subjects of Princess Cadence. Residing in the Crystal Empire, these ponies were introduced as a rediscovered species of pony in Equestria. It turns out this part of Equestria was taken over by an evil unicorn named King Sombra. Princesses Celestia and Luna managed to seal away King Sombra, but this caused the Crystal Empire to disappear. But now that the Crystal Empire has been rediscovered, Twilight Sparkle is tasked with preventing King Sombra from regaining control.
The Crystal Empire was currently under the rule of Princess Cadence and Shining Armor when Twilight Sparkle and her friends arrived. During The Crystal Empire Twilight and friends were tasked with finding out how to keep King Sombra away from the Crystal Empire permanently.
The Crystal Ponies were already introduced as unique to the initial Earth, Unicorn, and Pegasus from Ponyville. For one, their manes were animated to look a lot more shinier compared to a normal pony. It is after the main conflict of The Crystal Empire that the Crystal Ponies regained their true form.
The true appearance of the Crystal Pony emphasizes the crystalline aspects of their name. Now looking like something made out of actual crystal, the Crystal Pony gains a body that constantly sparkled. And the mane gains a more formal aesthetic. And as shown in The Crystal Empire, anypony can become Crystal Ponies if exposed to a significant amount of Crystal Empire magic, but only within the Crystal Empire itself.
First introduced and appearing in the Season 8 episode Sounds of Silence, the Kirin were one of the more unique types of pony in My Little Pony: Friendship is Magic. Looking a lot more reptilian compared to every other species on Pony in Equestria, these ponies resided in a secluded area called the Peaks of Peril. While the Kirin were characterized as a docile species, another pony type, the Nirik, were characterized as angry monsters of living fire.
The Sounds of Silence began with Twilight Sparkle assigning Applejack and Fluttershy to explore the Peaks of Peril, to solve a friendship problem for the Kirin. This idea was met with some apprehension, especially when the Nirik were talked about.
When Fluttershy and Applejack first meet the Kirin, some of their powers were shown. A telekinetic affinity to the earth which helped plants to grow and telepathy that allows the Kirin to carry objects. Basically, a mix between a Unicorn Pony and an Earth Pony. One specific ability that was revealed later in the episode provided the main conflict for Applejack and Fluttershy to solve.
The main conflict of this episode happens once the Kirin are introduced. Shown to be silent and expressionless, the Kirin were not as talkative as most ponies would have liked. They could only get yes-or-no answers to their questions. Applejack does get directions to meet someone who could answer her questions better.
After encountering Autumn Blaze, a Kirin that was a lot more talkative compared to the rest of the other Kirin, the reason why the majority of Kirin was revealed. Krin in My Little Pony: Friendship is Magic become Nirik when angry. In this particular case, the Kirin's ability to become Nirik when angry became so uncontrollable that Rain Shine, the leader of the Kirin, decreed that all of the Kirin had to use a magic emotion draining water to stay emotionless.
After Autumn Blaze shows that the Kirin could assume their Nirik forms for constructive purposes, the other Kirin agreed to get their emotions back.
My Little Pony: Friendship is Magic could be seen as one of the more unique My Little Pony cartoons because of how the show uses other types of pony species other than the original Earth, Unicorn, and Pegasus ponies. This allowed the writers to introduces different plot elements to the mythos of My Little Pony: Friendship is Magic. And while My Little Pony: Friedship is Magic as a whole is done as a series, the final episode does introduce one final plot point about Equestria's lore. In The Last Problem, the opening scene shows a Canterlot filled with different pony types other than Earth, Unicorn, and Pegasus ponies. And even non-ponies, too.