I recently faced the issue of how best to protect a live action character, with distinguishing features and a definite message. Neither trademark nor copyright registration alone would provide the full range of protection that combined filings would. what we decided to do was the register the character's name as a trademark (the name was available) and use as the description of goods and services, the message or meaning that the character stood for. This is what the public associated the character with. At the same time, we decided to file for copyright protection for the character's costume or design, linked to its name.
We believe this will provide the best protection possible.