"I'm definitely not working on less comics now that The Walking Dead has ended," Kirkman told ComicBook.com at San Diego Comic-Con. "I will continue putting out new books."
For Liefeld, who famously co-created Deadpool and Cable for Marvel Comics, "The next thing is to do a new, brand new line of creator-owned stuff that I've been working on for years," he said.
"Three pages of this, five pages of this, six pages of this. It's time to take them out, finish them, put them together, boom. And I'm sure he's got the same thing. Actually, I've seen all the things he's got coming, holy crap!"
The characteristically tight-lipped Kirkman gave no details, but Liefeld teased the "mogul" comic book creator is developing big works.
"The reason Robert can drop Die!Die!Die! and end Walking Dead is he is the child of Image ... Robert is the son of Image Comics. He's comics' first and only mogul," Liefeld said.
"You go to his house and he's like, 'Here, let me show you 200 pages of something I can't talk about. Here's 200 pages of my next project.' No one in this business can do 200 pages in advance, much less 400 pages in advance. I'm not doing it! When you say big risk, he takes big risk to the next level, and it is a delight. If there were no Robert Kirkman comics, it would be boring."
In a multi-page letter addressed to readers in July's final issue of The Walking Dead, Kirkman admitted he had "second thoughts" over his decision to end the book — but knew it had reached its natural end after completing Rick and Carl Grimes' stories.
"I don't WANT to do it. I'd rather keep going... but the story is telling me what it wants and what it needs," Kirkman wrote. "This needs to happen. Whether I want it or not."
"He did have a little bit of the willie nillies there in the last like ten days. And then it's the hottest thing. Who knew, ending a comic, biggest thing ever?" Liefeld told Comic Book.
"Five years ago, he has always said it ends with Carl. I will verify, brother knew how it was ending all the time, didn't change it."