The last one did happen. The earth pony one kinda did, but on concept art.

@Princess♠Molestia  
Discord did it again.

last one is ironic.

@SlayerBVC  
Den ota den.  
Goo joub.  
That really would have been a better episode.

Spike weee

You know what may have been a better plot for MMC?
 
2-parter  
-Twilight accidentally changes herself into an earth pony with a incorrectly cast spell.  
-First part of the episode is her trying and failing to adapt to not having magic anymore and trying to convince Rarity to take a stab at casting the spell on her again.
 
-We end part 1 when Rarity’s lack of expertise in advanced magic results in her losing control of the spell, transforming in Twilight becoming a pegasus. Final line of the episode. “My life is over… I’ll never be able to use magic again!”
 
PART 2  
-Twilight is still in shock from the spell failing and has broken down in tears. Fluttershy and Spike are the first to console her. Rarity tries to place the blame for the failed spell on herself, but Twilight says it isn’t her fault and that she shouldn’t have pressured her into using unfamiliar magic.
 
-Rainbow offers to teach Twilight how to use her new appendages and says that she and Fluttershy are more than happy to teach her the ropes about being a pegasus.
 
-Song Montage of Rainbow and Flutters giving Twilight a crash course on all things Pegasi.
 
-Princess Celestia shows up after she began to suspect something was amiss when over a week had passed since the date Twilight was to send her a report on the spell she was researching.
 
-Seeing Twilight’s predicament and having the experience to perform the counterspell, she prepares to change her student back to her proper race.
 
-However with all of the magic within her body from the 2 improper castings, Twilight’s body makes the counterspell behave differently and transforms her into a fusion of all three races. An alicorn.
 
END EPISODE

yes, it’s a twilight.

Pegatwi is actually pretty cool. And Erftwi would probably become a master of potions and shit under Zecora.

Now we just need to see her become a pegasus and the circle will be complete.

It occurs to me she’s been most of the forms on this list already.