@Wiimeiser
In the main story (FoE:Promise) we have old changeling Praetorian Ferrus who saved a filly Firefly and in the last chapters they found a hellhound puppy named Max.

But we still have the comic strip “Mother Wasteland” with reverse roles. It is here that the adult Firefly and Max find the young Ferrus. And although Max offered to name him after the old leader of the pack, but Firefly decided to name him Картоха (Potato). Well, they’re trying to figure out who he is and what to do with him, while trying to educate him.

As for me, the comic is very funny and, like in the book, Firefly constantly swears. Even her cutemark is a combination of the letters Ё and Б, which can be translated as “fuck”.

Just noticed Firefly has heterochromia (and her creator’s VK profile confirms this), so I added the tag. I also gave her a separate OC tag because Firefly is a common name.

@Re Pitter
Just to confirm for >>2560944, the giant changeling is named Ferrus? An AU profile with ages swapped suggests he’s “Картоха” but I don’t know for sure.

@Wiimeiser  
Archi (the author) had his own headcannon for changelings. Here it is Changelings of Equestria As for me it’s a perfect work, we have a lot of info: history, appearance, reproduction, even Hive architech :)  
One of the Changeling-praetorian survive Last Day of War, but got blind, so Ferrus just walk to wastland and kill and kill and kill for emotions  
In one of his quest he found Firefly/ Small filly who was modify to absorb radiation and pink cloud. She hare everypony.  
Her hate is so strong and pure that Ferrus begun remember who he is. So he guard his unlimited food supply and a lot of others what to get foal that can clear radiation.  
On the picture few Enclave pegasus try to steal her, but as you can see it’s end not so well for them  

@Re Pitter  
Unfortunately I have little understanding of Russian beyond how most of the letters are pronounced, and even then I don’t know what Х, Ц, Ч, Ш, Щ, Ъ, Ы, Ь, Э, or Ю do, expecially Ъ, Ы, Ь. I think АБВГДЕЖЗИЙКЛМНОПРСТУФ is ABVGDEƷZIYKLMNOPRSTUF, Я is Ya…
 
Also, I’m not sure of what the picture is about. I see Firefly sitting on another pony’s head, and I think that’s Pinkie who’s been impaled…

@Wiimeiser  
Here it is Fallout Equestria: Promise (russian only)  
Few other pics there like this one:It was a warning!

@Re Pitter  
Wow, I wonder what her backstory is…

@Wiimeiser  
and Firefly is absollutly crazy. She even kill Puppysmile once. Blind Changeling-praetorian guarding her.  
From description to this image:  

Checking the comments on the source page the filly is apparently “Firefly”. Also, the fic is exclusively in Russian.

Idk guys I think they’re just super into this game of hide and seek, not scared.

@Wiimeiser  
Puppysmiles is not scared. She is invincible. They should be scared of her.

I think that’s Morning Glory there. Also, who’s the filly they’re all scared of?

@zyonic  
It’s not her wing, it’s Murky’s.

Okay i more or less know who is who with the exception of that pony cow hybrid?
 
Also isn’t lilpip a unicorn not an alicorn? or did i miss something? gotta reread Fallout Equestria again.