Gimple was excited about two new additions to The Walking Dead, remarking, “We have a new character, Bob Stookey [played by Coleman's fellow The Wire alum, Lawrence Gilliard Jr.], who is coming on. Some major stuff goes down, which puts him in opposition to some major characters and gets him closer to other characters. We have a character we haven't talked much about, this character Zack played by Kyle Gallner (Veronica Mars, Smallville). He has a romantic relationship with one of the characters. That's a way very quickly that you get to know him. He's not one of our major new characters, but you get to know a lot about him real quick."
As for the new threat, Gimple could only tease its nature. “It's a force that you can't just stab in the face, you can't talk reason to."
Kirkman elaborated a little, saying, “Possibly the most deadly threat that they've faced thus far. They're still going to be dealing with the zombies, they're still very much a threat. They're still going to be dealing with humans, that's still very much a threat. But there's a new element thrown in, this new unseen force that is going to be extremely dangerous and possibly more dangerous than anything.”
“It would be an enemy in this world, but in that world, it's terrifying," said Gimple, before deadpanning, "White Walkers." Kirkman joined in with, “Dragons!”