While I was putting together an article for another wiki on Halloween costumes, I came across several My Little Pony costumes. Here's an overview of what's available. It doesn't cover masks, accessories or makeup. There were also a couple of characters missing, so I tried to come up with workarounds for them.
Unless a costume is specifically listed for teens, many of the adult costumes will also fit them. Check the websites for pricing, available sizes and what's still in stock.
- Girls'/teens' costumes
- costume #1: dress with tutu skirt and Pinkie's cutie mark, ears headband with mane, tail, glovelets
- Pretty: long-sleeve leotard printed with a picture of Pinkie, ears headband with mane, clip-on tail, sequin tutu
- Deluxe, at Party City and Spirit Halloween: pink ruffled dress, detachable tail, arm and leg warmers, headpiece (not quite a mask, but it looks more like a Generation 1 or 2 pony)
- costume #2: party dress, ears headband
- costume #1: dress with attached tutu and blue bow, tail, arm warmers, blue wings, ears headband with mane
- "trendy" costume: hoodie with mane, rainbow tutu, rainbow knee-high socks
- for teens: similar to #1 but with a different dress with suspenders, and includes leg warmers
- costume #2: dress with tutu, wings, tail, headband with ears only and a bow
Star Song (Generation 3 pony):
- Deluxe: dress, detachable wings, tail, hoof style arm and leg warmers, headpiece (same style as the headpiece from the Deluxe Pinkie Pie costume above)
- costume #1: dress with tutu, wings, headband with ears only and a bow
- for teens: sleeveless dress (attached furry vest, corset-inspired bodice with lace-up detail, tutu skirt), glovelettes, ears headband with mane, furry leg warmers
- Women's costumes
- costume #1: dress, wings, tail, wig, hoof style leg warmers, ear headband
- costume #1: dress with tutu, leg warmers, tail, wig, ear headband
- Flirty: hoodie with mane, rainbow tutu, light blue furry leg warmers
- Raving: rainbow tutu, light blue furry leg warmers, suspenders, glovelettes, wig
- Sassy #1, at Party City and Spirit Halloween: dress with attached tutu, wig, ears headband with mane, wings, hoof style leg warmers
- costume #1: light blue dress with hood and blue faux fur trim (on the wrists, hem and hood), matching faux fur leg warmers, tail
- Cozy: same hoody and tutu as the Flirty costume, but with printed leggings instead of the leg warmers
- Sweet: same printed leggings as the Cozy costume, but with a wig and a tank top
- Sassy #2: same printed leggings and tank top as the Sweet costume, but includes a "snood" (hood with attached pony ears and felt rainbow mane)
Sundance (Generation 1 pony):
- costume #1: dress, petticoat, ears headband
- costume #1: tutu, footless pink tights, hoof style leg warmers, wings, ears headband with mane and horn
- Sassy, at Party City and Spirit Halloween: light purple dress with glitter tulle bodice, hoof style leg warmers, tail, wings, wig, headband with ears and horn
As you can see, there are several gaps. For girls, there are costumes for only half of the Mane Six, with at least two costumes available for Pinkie Pie, Rainbow Dash and Twilight Sparkle. For women, they add one costume for Fluttershy, but only offer one costume for Pinkie Pie.
The closest I've been able to find for a store-bought women's costume for Rarity would be this plain white unicorn costume. The Purple Monster Wig is a pretty good candidate for Rarity's mane and it should be easy enough to add her cutie mark to the dress. Not sure what you'd do about the ears, though. These cat ears could work if you could remove the pink satin from the inside or cover it up. Or you could modify this unicorn headpiece.
That same costume could be dyed to become an Applejack costume and matched with the blonde bombshell wig since that's got the right length and sweep to the bangs. There's a pretty good tutorial on how to make a girl's Applejack costume. They show a picture of dyeing the mane and tail, which are made with tulle fabric. I had to look that up. It's a fabric that's used for veils and the like.
For girls, do-it-yourself is the only choice for the missing Applejack, Fluttershy and Rarity costumes. A Rarity costume should be the quickest to make since you're only dyeing a mane and tail and adding the cutie mark. An Applejack costume involves a little more work since you're also dyeing the shirt, shorts and leggings. Fluttershy would be the same process as for Applejack, but a lower amount of dye to get her pale yellow and pink coloration. If you go to the page on the Michael website that shows Rit Liquid Dye, they have fuchsia. You'll have to use the drop-down menu to select lemon yellow. I recommend starting off with a real small amount of dye and a couple spare scraps of white fabric. If it's not dark or rich enough, you can always re-dye the fabric until you get the right shade of the two colors.
Obviously, this is something you'd have to start on pretty quick to ensure you'd have it ready by Halloween.
If you're going the DIY route, a website called illistyle has some templates you can download for MLP DIY masks. All you need is felt in the appropriate colors, scissors, pencil and fabric glue.
With any franchise, they can't make a specific type of merchandise for every character in the series. Well, excluding "blind bag" products where the whole idea is to have a lot of characters and you don't know which one you'll get, so you wind up buying a lot more in trying to get a full set.
But when you've got a well-defined set of lead characters like the Mane Six that are pretty well equal in importance and popularity, to not see costumes for all of those characters is a bit unusual. Why don't the girls have Applejack, Fluttershy and Rarity costumes? And why don't the women have Applejack and Rarity costumes?
Doesn't make sense, especially since these are officially licensed costumes. It also doesn't make sense why we have Star Song and Sundance costumes instead. I have no idea how popular they are from the previous generations, so I don't know why those are even available for sale.
And one other costume I really don't get is the blue onesie/pajama men's costume. It has Dash's cutie mark on it and a "printed wing detail" on the back. But it has what looks like a multicolored Libman Wonder Mop for a mane. If you're a guy and you really want to be Rainbow Dash, this is about your only choice for a store-bought costume. But hey, it's an officially licensed costume!