According to The Hollywood Reporter, Andrew J. West is joining Season 4 as Gareth — a role that's apparently pivotal, with an option to be promoted to series regular in Season 5..
Not that we're surprised that AMC is staying mum on the details. Any The Walking Dead fan is used to being kept in the spoiler-free dark. But the name Gareth, not being a part of The Walking Dead comics/graphic novels, gives us less than usual to go on, although sources told the site he'll be "a remix of sorts of an unidentified character from the series." If Andrew looks familiar, you may have seen him on Greek orPrivileged, or as the iPhone in those T-Mobile commercials. There are all kinds of worlds from the comics that we haven't delved into in the series yet.