When our 5-year-old son saw a trailer for the movie 9 he insisted on being the 9 character for Halloween even though he couldn't actually see the PG-13 rated movie. It was so visually interesting that we agreed it would be a fun costume idea. However, there was nothing out there that we could buy or build on, so we created the Homemade 9 Character Costume from scratch.
For the body, we used a basic kid costume pattern from a fabric store (one of those that can be used to make a hundred different things) and chose burlap for the fabric. I'm not really a seamstress, and I didn't think my sewing machine would work with burlap anyhow, so we actually hot-glued the fabric together. I then applied stitching with yarn around false seems around the arms so that it would look more like the character.
The head was made by applying paper mache over a party balloon, then cutting out openings for the eyes, mouth and neck. We then used spray adhesive to cover the head with burlap. We saved this step for last because we had no idea how we were going to apply the burlap to the curved surface of the head, but it actually worked out fine and ended up being fairly easy to do.
For the eyes themselves, we just cut a poster tube into sections, then applied paint and metallic details. Those were hot-glued into the eye openings after the burlap was dried onto the paper mache.
Most of this costume was done on the cheap, with the exception of the copper. The movie character has several copper parts and my husband insisted that no substitute would work. So to my chagrin he blew the money on several copper sheets, which he then used to finish the costume. Even though I couldn't believe he did that at the time, it really did make the costume look cool. The large zipper piece was just cut out and then painted to look aged and dirty. He made the hands by gluing several little pieces of copper to gloves, like armor (this was the only way our son would still be able to move his hands).
It was a ton of work, but our son had a blast on Halloween night, which made it all worth it.