I decided to make a quick breakdown of my pony ninja outfit for the heck of it and because I like explaining this sort of thing. As to why Rainbow over Rarity for a clothing pic… I was already working on a Rainbow pic.
 
Usually the bottom most layer of my ninja outfits are the underwear, but pony’s don’t normally wear clothes so the base was just for fun and context.
 
The main part of the outfit is a Shinobi Shozoku (ninja outfit) modified for ponies, and other quadrupeds. The whole outfit is one piece that the pony must first step into hind legs first (sliding their tail through a hole in the back), then putting their front hoofs into the front sleeves and sliding the whole thing into place, and finally fastening the overlapping parts of the front chest into place. The fore and back legs are padded, represented by the accented parts, for extra protection. Pegasai and other winged creatures have holes on the sides for their wings.
 
Finally is the hood, totally head covering and totally optional depending on the situation. How they get the hood on is debatable and depends on the pony, advantage unicorns, but is probably similar to their ability to hold guitars and such. The part covering the mouth is stretch-ier and can be easily pulled down for easy access when they need to grab something with their mouth. Unicorn models have a hole in them to allow for their horns so they don’t have to make one themselves (leads to some issues when a unicorn tries to put on a non-unicorn mask).
 
I doubt any of you really care about the specifics of my outfits but I enjoy this kind of thing and if nothing else you get another pic from me.  
I don’t own this character just the pic