Little Mermaid Party   For the invitations I used an idea from the web.  A sandwich bag with sand in it and fish confetti etc.  The invite was written on blue post cards and placed inside the bag, and it all fit into an envelope.  The house was decorated with white string across the longest part of the room and blue and green streammers threaded through it to look like you were under water.  We had blue or green sheets etc to cover any furniture or tables etc. The cake was a mermaid cake. We did the scavanger hunt for a treasure chest. We also made "shells" out of paper plates and attached these to a board with staples. In each shell was a S M or L.  Which ever the child hit with the beanbag starfish, they got to choose a small, medium or large prize. For goody bags, we used brown paper bags and drew a treasure map on each.  This was a Halloween birthday, so we all dressed up.  My 3 year old was the Ariel the Mermaid.  I was Ursela, black sheet and hangers to make tentacles stand up.  My 4 month old was Sebaston, in a red onesie and red tights.  I used craft foam and made the shell and claws.  I hot glued these to the onesie.  My husband was King Triton. We made him a tale, used an old devils fork and repainted it brown and gold, got him a long blonde wig, and used a flesh colored leoatard and drew the muscles on it too! I also made the crown out of craft foam. We had the movie on in the family room during the party. The kids loved seeing us and matching us to the movie. This year we are doing Peter Pan.