The latest trailer for "The Walking Dead: Dead City" reveals the new villain, The Croat, who kidnaps an older Hershel. Maggie seeks help from Negan to rescue her son, who has a mysterious connection to the new villain. The trailer suggests that The Croat knows Negan, leading to speculation about a possible connection to Negan's past before he joined the show. The show's villains are expected to be original characters, and the trailer hints at a potential Negan redemption arc. The reason behind Maggie's decision to work with Negan is explained by The Croat's connection to him, and it also explains why Hershel is kidnapped.