I have to amend what I said about characters not being copyrighted -- it's a bit trickier than what I was thinking. Basically, a character is copyrighted IF he appears in a copyrighted story -- but he has to be a very distinctive character that is so realized that he takes on a life of his own. That is, Mickey Mouse (to use an example) is a definite personality who has a recognizable personality and character, whereas some goat named Nate who just does a walk-through with no lines is a complete abstraction. Mickey would be considered to be copyrighted, but Nate wouldn't be. But any character that is that well-defined is going to be further protected by Trademark, so the copyright protection alone is going to be pretty moot.
I have to amend what I said about characters not being copyrighted -- it's a bit trickier than what I was thinking. Basically, a character is copyrighted IF he appears in a copyrighted story -- but he has to be a very distinctive character that is so realized that he takes on a life of his own. That is, Mickey Mouse (to use an example) is a definite personality who has a recognizable personality and character, whereas some goat named Nate who just does a walk-through with no lines is a complete abstraction. Mickey would be considered to be copyrighted, but Nate wouldn't be. But any character that is that well-defined is going to be further protected by Trademark, so the copyright protection alone is going to be pretty moot.
Further detailed info on this point is here: http://www.publaw.com/fiction.html