Image imported from derpibooru 
Original Description:
 
Artist link: https://www.deviantart.com/monere-lluvia
 
Short story:  
Snowi was an ordinary lazy mare in a bunker full of nerds and scientists, but on her eighteenth birthday, the bunker was attacked by a bunch of evil ponies from the radioactive wasteland. They kidnapped all the inhabitants of her bunker, but she managed to avoid capture because earlier, during the repair, she got her butt stuck in the ventilation tunnel and couldn’t get out. When she finally managed to break free, destroying the entire ventilation shaft in the process, She discovered that they had all been abducted. So she ran to the armory, to provide herself with the best gear available, and followed the kidnappers to free her friends. Barely 10 minutes after coming to the surface, she almost died in an ambush by the hands of a mutated praying mantis and some dungy beetles. She managed to escape and finally track down kidnappers. She reached another nuclear bunker where mad scientists conducted crazy experiments, mutating the kidnapped ponies in an attempt to create a radiation-resistant pony. For this purpose, they combined the DNA of a pony with other species of creatures resistant to radiation, which resulted in a whole lot of abominations (unsuccessful experiments ). Snowi tried to sneak into the lab and free her kin, but she was caught and a gruesome experiment was carried out on her. During the procedure, the mutants got free and began to murder scientists, so Snowi transformation was interrupted in the middle. Thanks to this, she managed to get off the laboratory table and escape from the enemy bunker which soon after exploded as a result of the nuclear reactor explosion. Deprived of her family and purpose in life, Snowi wandered in radioactive wastelands and it soon turned out that as a result of an experiment, mutations began to appear on her body — clawed paws instead of front hooves, mantis scythe as an extra limb, tentacles, spikes, other unusual things, and to make matters worse, she began to hear voices in her head urging her to do strange things. Thus other civilized ponies living in the wasteland soon began to hunt her. So to solve this, she subjugated a gang of feeble-minded bandits, to training them into an army, consequently, she started many wars, fighting with other ponies factions, for lands where she could live in peace, away from the stupidity of other ponies and the madness of the radioactive wastelands of the nuclear world.