I think what they are are the big huge bags made of some sort of plastic covered woven material. You can usually find them at the resort gift shops or some of the larger ones in the parks.

Normally we'll purchase one and use it to carry our big souvies that don't fit in our suitcases, and use it as a carry on for the airplane.

We have quite a few of them, and they usually have the logo of the celebration going on, or a picture of all sorts of characters and the castle.

We now use them to store Christmas decorations in.