Greek and Privileged alum Andrew J. West has joined The Walking Dead as a mysterious new character The Hollywood Reporter contends will be a "big presence" in the hit drama's fourth season.

The website reports he'll play Gareth, which sources say is "a remix of sorts of an unidentified character" from the Image Comics series by Robert Kirkman and Charlie Adlard. West will be credited as a guest star this season, with the possibility of promotion to series regular with the recently announced Season 5.

West follows recent casting additions Christian Serratos, Michael Cudlitz and Josh McDermitt.

The fourth season of The Walking Dead premiered Oct. 13 to record ratings, attracting 12.4 million total viewers and 8.1 in the coveted 18-49 demographic. The series airs Sundays at 9 p.m. ET/PT on AMC.