"The Walking Dead" creator Robert Kirkman, artist Charlie Adlard, and Skybound editorial director Sean Mackiewicz took to the stage once more at Comic-Con International in San Diego to discuss their juggernaut series, along with the two AMC television series it inspired. "The League" actor Jason Mantzoukas moderates the panel.

Kirkman said that "some characters are introduced with a very clear arc," but "other times I'm writing an issue and I just go, uh, this issue's a little boring," in which case he'll kill a character unexpectedly.

Something like The Whisperers, "that takes years" to develop. "I have notes for Negan that go back three, four years before issue #100," though sometimes details or names will change as they gestate.

"Other times I go, it would be cool if people would wear zombie skins."

A baby cried, and Kirkman brought it onstage. He and the moderator then discussed the practical aspects of wearing zombie skins. "What if you get a skin from somebody that's not bigger than you?" Mantzoukas joked, adding that probably there would grow an industry of "skin tailors." Kirkman returned the baby to its father.

After holding forth at length about Carl losing his virginity, Kirkman said that if Adlard would draw nudity, obviously all the characters would be nude all the time. "The zombies wouldn't know where to bite -- there are too many options!"

Mantzoukas noted that the Whisperers wear a layer of skin, then clothes over that, leading Kirkman to say he felt sorry for the actors who would have to portray them, while filming in Georgia. "Forget about those issues with the Whisperers, I'm taking them out."

Discussing Rick's leadership, Kirkman said that "it's important to me that Rick is never seen as an expert." He'll take Negan's advice when it's useful, if "he feels it's the best way to protect his people."

"If you didn't see Rick all the way through this journey, if you just popped into any moment in this series, you'd go, wow, this guy's a monster," Kirkman said.

Adlard noted the same was true of Negan. "If you read his whole backstory, you can sympathize," the artist said. Kirkman reminded folks that this story is told "four pages at a time" in "Image+," and "that will all be collected when it's finished."

Mantzoukas noted that "if you'd built a book around Negan and he encountered Rick Grimes, Rick could be the villain of that series."

Adlard talked about drawing new characters and thinking they were minor, throwaway characters, but some would become important and recurring. "And then I'm stuck with this face!"

Mantzoukas played a slideshow of butt cracks showing in Adlard's work. Adlard joked that this was simply reflecting reality. "Honestly, I think people who don't draw the butt cracks are doing it wrong," Adlard said.

The floor was then opened to fan questions.

Asked who Negan kills on the show, the panelists stressed that this is a panel for the comics. Kirkman said, though, "It's not Rick."

Kirkman said Negan's name was originally "Negas," because he wanted something that sounded negative. But "then I remembered that the high commander of the Ferengi in 'Deep Space 9' was the Grand Nagus, so I thought, oh, that's where I got that -- maybe his name is Negan."

Asked whether Rick's group would take up the Whispers' practice of wearing skins, Kirkman said, "you're on to something."

Kirkman said his best moments, such as the line of heads, "are the ones where I give Charlie the room to play" and "make us spend the time on those moments we don't want to spend a lot of time on."

Adlard said this was also one of the few times he had to call Kirkman in surprise, "because I didn't know that was going to happen." "I kept turning the page and was like, 'oh.' 'Oh...' Oh...!'"

But Kirkman said this may be a factor of earlier in their collaboration when he'd get Adlard excited about something that may still be two years off.

"I enjoy reading it as a fan rather than knowing months in advance what's going to happen," Adlard said.

"I forget the stories I write almost as soon as I'm done writing them," Kirkman said, "so I get the art pages back and I'm like, Oh my God!"

Though Kirkman has said that he knew how the series would end, "The end has changed," he said. "There was one version that would have had it ending as soon as everybody reached Alexandria."

Asked about characters he regrets killing, Kirkman said "I always liked writing Tyreese, I wish I still got to write him. I wish I still got to write him on the show." But he has no regrets. Mantzoukas joked that Kirkman should write in the actor/singer Tyrese, leading the conversation to devolve into a great deal of banter including mentions of Sammy Hagar showing up.

Adlard, who is not familiar with Sammy Hagar, referred to his music as "soft rock."

Kirkman said that he wrote Abraham's death as he was writing the issue. Originally, both Abraham and Eugene were going to survive, but "then I thought, that's bullshit."

Adlard said the only scene was uncomfortable with Michonne torturing the Governor. "I phoned him up and asked him, do I really have to draw this?"

"Yep," Kirkman said.