Seth Gilliam, who most recently recurred on MTV's "Teen Wolf," becomes the third "Wire" vet to become a series regular on the zombie drama.

AMC's The Walking Dead is adding another Wire alum to its cast.

Seth Gilliam has boarded the zombie drama as a series regular for its upcoming fifth season, The Hollywood Reporter has learned.

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The actor, who played Ellis Carver on The Wire for its entire five-season run, becomes the third alum from the acclaimed HBO drama to join the AMC series based on Robert Kirkman's best-selling graphic novels. Chad Coleman (Tyreese) and Larry Gilliard Jr. (Bob) also count The Wire among their credits, and Kirkman is a big fan of the series.

Details on just who Gilliam will play on Walking Dead are being kept under wraps. The casting breakdown -- which used the dummy name of Michael -- described the character as friendly with a puckish demeanor who also has a haunted side, though that is not expected to be accurate, either. (There also is not a character with the name Michael in the ongoing comics series, unless you count a small boy named Mikey.)

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Given the casting description and where the zombie drama is creatively, THR's best educated guess is that Gilliam is playing Gabriel Stokes, a preacher who first crosses paths with Rick in the 61st issue of the comics -- just before the ragtag band of survivors encounters the Hunters (aka the cannibals). Not long afterward, Gabriel reveals the dark lengths to which he went in order to ensure his survival and becomes a member of Rick's community. (He's also still alive in the comics.)

Showrunner Scott M. Gimple told THR that season five will focus a lot on humanity, and the addition of a potential preacher could speak to that. "Rick said, and before that Robert said it in the comics: Are we too far gone to be people anymore, to actually be human beings, to be able to relate to one another on an emotional level, to be able to live a real humanistic and emotional life -- are we too far gone?" Gimple said after the season-four finale. "Next season really is whom do we become after that? Once that question is answered for ourselves, who are these people? That idea will be explored a few different ways."

Gilliam becomes the latest series regular to board Walking Dead, which has already started production on season five. Andrew J. West (Gareth), Alanna Masterson (Tara) and Christian Serratos (Rosita) were all promoted to regulars for season five in March after recurring in season four. West, who made his debut during the season-four finale, plays Gareth, who is the head of the group living at Terminus -- who may or may not be overseeing a group of cannibals. THR exclusively reported that the Greek alum signed on to the series in November with an option to be a regular in season five and that the character would have a big presence and play an important character on the series. (And he certainly did: Gareth currently has nearly everyone trapped at Terminus in one of the show's most dramatic cliffhangers yet.)

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Gilliam, who has been recurring on MTV's Teen Wolf, is repped by Gersh and McGowan Management. His TV credits also include Oz and episodes of Homeland and The Good Wife.

The Walking Dead returns for its fifth season in October. An exact date will likely be announced in July at Comic-Con.

Email: Lesley.Goldberg@THR.com

Twitter: @Snoodit