These are very small Disney Princess dolls that come with a couple rubber stretchy dresses (designed after something the princess in question wore during their main movie). They come with a friend from the movie, and some shoes, as well. So, Ariel, for instance, comes with Flounder, a tail with purple bra, a pair of pink shoes, and that pink and white dress she wore in the movie, after her bath in the castle.
My kids love them, and we have just about all of them (they also come in larger packages, with sparkly keep sake bags and more clothes/friends, etc.). The problem is that you'll find yourself having to replace them a LOT.
They aren't very sturdy little things, and the pieces are so small, I've probably vacuumed most of the shoes and friends up without even knowing! The only reason I give them such high marks in certain areas, is because my children love them so much.
We've tried various things, to keep track of the shoes and friends, and stretch out the amount of time it takes for one of my kids to destroy the dresses by stretching too far. Forget about it. The shoes will get lost, probably within the first 24 hours of ownership. The friends will probably be lost in the bottom of a toy box, never to be seen again. And, the dresses will last around 6 months before they're likely ripped in places, and looking 'not so fresh'.
There are much better Disney Princess doll options available.