Step 1: What You Will Need
and an empty film cannister
Step 2: Putting It Together
First you will need to punch holes in the bottom of the film can and the side see pictures 1 and 2(bottom is the side that doesn't come off also make sure the straw fits snugly into the bottom hole)
Next take your balloon and cut it so it looks like the one on the right in picture 3. Cut it in half and then cut off the bottom pat where you blow.
After that stretch it over the top of the film can without the cap put it on while the balloon is stretched over put the top back on see pictures 4 and 5.
Last put straw in bottom and move it until when you blow on it makes a noise.