It's Finnish. Below it you see the word "megapåse", which is the same thing in Swedish.
Pussi = sack or bag.
Somewhere in my pile of things there is a paper sack I saved from when I was in Helsinki, from a sweet shop called Karkki Pussi.
For good anti-social fun, next time you're in a shop, ask the clerk if they have a pussi, or better yet, tell them that you need a pussi.