Robert Kirkman's The Walking Dead comics have provided fans with a slew of memorable heroes and villains over the years, many of which have been brought to life on the massively-popular AMC TV series. There is one character, however, that fans have been clamoring for more than anyone else, the brutal villain Negan. Showrunner Scott M. Gimple has always played coy about whether or not Negan will surface at some point this season, and a casting call from September seemingly teased that the producers were searching for the right actor to play him, even though this particular character was named Rich. Today we add another mysterious piece to the Negan puzzle, which comes from actor Garret Dillahunt, who tweeted a photo of his "reading material," The Walking Dead Compenium #3, the same volume where Negan first appears.

Naturally, a photo of a comic book is far from any sort of casting confirmation. The actor did include The Walking Dead comics Twitter handle (@TheWalkingDead), which responded by saying the comics team are "big fans" of his work. It's worth noting that he didn't tweet this photo to the TV show's Twitter handle (WalkingDead_AMC). Still, the actor's seemingly random tweet and the recent casting rumors have fans in a frenzy, wondering if Garret Dillahunt is in fact Negan.

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Shortly after the September casting notice surfaced, Xander Berkeley signed on for a top-secret but important role in the series. Many assumed that he signed on to play this mysterious "Rich" character believed to be Negan, but nothing has been confirmed about his character, except that he will debut in the second half of the season. The casting breakdown described the "Rich" character as a 50-something narcissist with an angry streak, the charm of a Senator and charisma of a used car salesman. While all of these qualities match up with Negan, the villain is a bit younger in the comics, in his late 30s or early 40s.

While it's certainly possible that the show could be seeking an older character to play Negan, we have no confirmation about their approach to casting this polarizing character. It's worth noting that Xander Berkeley is 59 years old and Garret Dillahunt is 50, so if the network was looking for older actors for Negan, they would both fit the bill, in this aspect. However, there are more clues that Garret Dillahunt may be joining The Walking Dead as Negan, or another mystery character.

The Walking Dead cast members Alanna Masterson and John Carroll Lynch recently started following Garret Dillahunt on Twitter, as did showrunner Scott M. Gimple, who only follows 301 people on the social networking website. In response, Garret Dillahunt followed both Scott M. Gimple and the show's official account. Does this all mean that Negan will be popping up on The Walking Dead this season? Take a look at Garret Dillahunt's tweets below, including a cryptic response to a photo of a bat wrapped in barbed wire, and stay tuned for more updates