Here is the finished product. I think I would go round all the edges with masking tape (on the inside) before putting it together if I were to use butcher paper again. The paper is quite flimsy and thus prone to tearing when stuffing it. I only did the top edge to give it stability and strength to hang it. All edges would be much better. Anyway I also ended up using paper towel (can you believe we didn't have a newspaper in the house!) which is particularly good for the smaller area's such as the mouth as it's much softer.
Load up the stapler because you need lots of staples to put it together properly. You certainly don't want paper peeking through in between the gaps. Good enough to hang up her brothers sea themed room!