who is gareth?

so far all we know about him his is found right in this article http://blog.zap2it.com/frominsidethebox/2013/11/the-walking-dead-season-4-casts-andrew-j-west-in-mysterious-role.html it says "West will play a character named Gareth, who isn't found in "The Walking Dead" comics. It's being reported that he'll be a "remix" of an "unidentified character from the series," and that he is a "big presence" and plays an "important character" in the show."