That fake Rarity kinda looks an X-parasite from Metroid mimicking Rarity, kinda like the SA-X mimicking Samus.

Rarity: You will not take Sweetie away from me, you evil faker, I hope you will like this anti-magic bullet!

note: the monster who look like Rarity, is a evil creature who attack only young kids by take the look of a family member to trick them, those Creature are weak only anti-magic ammo or normal sword, do not use magic on them, is will make them more powerful and mostly if the creature a take your look and target a member of your family, but a good shot on the head or heart will destroy it, but make sure you have a clear shot, oh and nerve attack it with your fists or kick, only use weapon as long is not a magic one, those creature are immune to it. Rarity a say to sweetie to not look to the eyes of her faker or she will die, Rarity have with her anti-magic bullet give by Celestia to deal with this faker, like Celestia a deal with a Faker like this when Luna have Sweetie age and what make worst, this creature is then same who attack Luna but Celestia a fail to destroy it but create the anti-magic ammo to destroy it and this time Rarity will finish this unfinish business who old then 1200 years but what make Rarity angry is this monster a dare to take her look and target sweetie and for this she will make it pay for this with a bullet to the head

@CaptainXtra  
From the looks of it, Rarity being a good big sister and protecting herself and Sweetie Belle from whatever the hell that thing is.

3 years and no answer.
 
The fuck is going on in this picture?

What the fuck is that thing?

@Amagan  
You’re right on the money there

@Cyborg_pony  
I think only Sweetie Belle is wearing underwear though

@DrCoolcabbage  
Makes it harder to carry spare ammunition though.

@DrCoolcabbage  
Just gotta run faster than your pants!
 
 
@Cyborg_pony  
Ooph, yeah, would hate to run away form the monster only to be humiliated from nudity X3

@Cyborg_pony  
It’s a fantastic day to not wear pants. They weigh you down and restrict your movement, so without them, they have a better chance of running away!

@Jawolf  
At least she’s wearing underwear. Unlike another incident that happened. At a party no less. :V

@Cyborg_pony  
What a time for some monster to attack, right after her shower.

Bad day to not wear pants.