One of the many characters fans are still waiting to see on The Walking Dead is the villainous Negan from Robert Kirkman's original comic books. A rumor surfaced earlier this month that the show's producers were "secretly" casting Negan, but that was never confirmed. Today, we have word from TV Line that Xander Berkeley has been cast in a top-secret role, although sources claim that he is not playing Negan. Even though he does match some of the same attributes.

Xander Berkeley has seemingly signed on for the same character that was revealed in a casting breakdown earlier this month, who many thought was Negan. The character is described as a narcissist with a huge ego, who "relishes" the thrill of being in control, which he plays off with a "car salesman" like charm. The report from earlier this month stated this character's name is "Rich," but TV Line reveals the character name is being kept under wraps, for now.

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Whoever Xander Berkeley is playing in The Walking Dead Season 6, the character won't debut until the second half of the season. It seems that AMC and the show's producers plan on having the actor stick around for awhile, since his deal includes an option to become a series regular in the inevitable Season 7. Since we know for sure that this character isn't Negan (probably), there is a theory about who this mystery man may be in the zombie series.

There is speculation that Xander Berkeley may actually be playing Gregory, the cowardly leader of the Hilltop Colony, where Rick (Andrew Lincoln) and his crew are rumored to visit later this season. Gregory is in the same age range as "Rich," and he is also prone to angry outbursts, who can be equally charming and charismatic when needed. While it has never been confirmed that the Hilltop Colony comes into play this season, given actor's age, and the similarities between the casting breakdown and the character from the comics, don't be surprised if Xander Berkeley is confirmed to play Gregory.

Xander Berkeley joins other new characters this season such as Corey Antonio Hawkins' Heath, an Alexandrian supply runner, Merritt Wever as Dr. Denise Cloyd and Ethan Embry as Carter. Xander Berkeley most recently starred as Magistrate Hale on WGN America's Salem and as Ronnie 'Dogstick' Brannigan on CBS' summer series Zoo. He may be best known for his time spent as George Mason on 24. Do you have any theories about who Xander Berkeley may be portraying in The Walking Dead? Chime in with your thoughts and stay tuned for more before the season premiere airs Sunday, October 11 at 9 PM ET on AMC.