This POW Block can release a mushroom or a coin with compressed air. Hit it and you will receive your item!
POW Blocks in action: [link]
Make your own: [link]
It comes in 2 versions:
This blue block releases a mushroom. It has very complicated folds, I recommend it only for advanced papercrafters.
This red block releases a coin. It is very easy to build, you can see the modeling process in this video: [link]
All crafts on: [link]