Released last year as part of the 30th Anniversary of Ghostbusters, the Stay Puft Marshmallows were only really available to begin with, in the USA but have since found their way into UK stores, namely Pound World, where they are often sold alongside Twinkies. The front of the package has a large graphic of Mr. Stay Puft with a giant American flag in the background. Behind Stay Puft is a cityscape designed to resemble New York. There's also a large window that allows you to see in and look at the Marshmallows.
There's not much on the back of the bag other than ingredients, nutritional information and underneath all that, copyright information. The American flag theme follows onto the back of the packaging.
Soft, white and fluffy is the best way to describe the marshmallows once they're out the bag. There's also a strong smell and taste of vanilla coming off them as well and I do mean strong. I personally got a little addicted to them. I tried one and next thing I knew, I'd eaten half the bag. If you can find them on the secondary market or even through your local Pound Land (In the UK), then I'd highly recommend that you get yourself a bag. They also come in mini mallows as well.