Taking a look at the list of comics released each month makes a few things abundantly clear. One is that there aren't a lot of books hitting the century mark these days, and another is that Robert Kirkman writes a lot of comics. He currently writes "The Walking Dead," "Invincible," "Super Dinosaur" and co-writes "Thief of Thieves" in a TV writer's room-like situation, all for his Skybound imprint published through Image Comics. He also has a long awaited one-shot called "Hardcore" coming out from Top Cow with artist Brian Stelfreeze, a TV series based on "The Walking Dead," and a new show in the works based on "Thief of Thieves," both at AMC.

Kirkman has not just one, but two series' under his belt about to hit the 100-issue mark in 2012, with "The Walking Dead" reaching the milestone first in July and "Invincible" a few months later. The undead horror comic kicked off back in 2003 with Tony Moore drawing the first six issues and then Charlie Adlard illustrating the rest. The comic defied conventions by not only consistently gaining readers, but also doing something many readers had thought impossible: truly shocking the audience. CBR News spoke to Kirkman about the disturbing moment that still haunts his dreams, where things will go with issue #100, and why he thinks the series remains so popular.

CBR News: "The Walking Dead" is not only one of the most popular comics around and one of the best sellers in trade paperback, but it has also spawned a TV series, video games, action figures and board games at this point. What do you think makes the property so popular and versatile?

Robert Kirkman and Charlie Adlard have left a trail of bodies in their wake as they prepare for "The Walking Dead" #100

Robert Kirkman: I have no idea. I think zombies are cool, I think the characters are at least somewhat interesting, I don't know, man. If there was one little thing I could do to pinpoint exactly what was making it a success, I would definitely be replicating it as much as possible and then retiring, but I don't know. I feel extremely fortunate that people have grown to love the concept as much as they have and it baffles me that it's grown so big, I really don't know what it is. I do know zombies are awesome and it's fun to read things in that world, but I don't really know.

One of the elements that I think makes it so appealing for readers coming in is that you and Charlie Adlard have been working on this book for 93 issues and it all looks so consistent. How has your working relationship changed, do you guys work with a shorthand now?

Yeah, my scripts have gotten totally crappy, it's gotten to the point where I can just be like, "Remember that place you drew a thousand times and they're over there talking and then that guy gets his head blown off, I don't know whatever." It's become a lot easier of a working process. I know Charlie can handle pretty much anything I throw at him. When I think of everything he's accomplished month in and month out over the course of these 9 years we've been working together, it's absolutely staggering. All I can really say is that the best is yet to come and we're both really excited about where the book is going and just really having the time of our lives. Even though we've been doing it longer than we ever thought possible, I think we both feel like we're very much at the beginning of this journey.

Speaking of moving forward, and I know you don't like to give much away about upcoming issues, but can you tell us anything about what happens in "The Walking Dead" #100?

I can say that everybody knows that there's this group out there called the Saviors that are kind of intimidating everyone on the Hilltop. They've kind of gotten on Rick's radar, we [saw] their first interaction in #97. We've basically got another very violent, dangerous group out there that Rick is going to be clashing with head-on and I can say that issue #100 is going to easily be the most gruesome, most violent, disturbing issue of "The Walking Dead" yet. So, be on the lookout. Yet, when I say that, I do remember all of the gruesome, disturbing and violent things that have happened in "The Walking Dead" thus far, so I promise I mean it.

In a lot of comics, you hear that kind of tease and it feels like bluster, but considering all the insane things you've done, readers must take you seriously. Are there moments that even surprised you with how far they went?

Seeing that baby arm come out from under Lori with her staring at you with those dead eyes in that panel Charlie drew [in "The Walking Dead" #48], that panel still haunts my dreams. When I wrote that, I was really upset and like, "Ah god, we're killing this baby, but we've got to do it, it's 'The Walking Dead.'" And I never in a million years expected that panel to affect me the way it did when Charlie turned that page in, but that's a real tough one for me, but it's part of the job. You gotta do what you gotta do.

Is it difficult keeping up that kind of pace and intensity in the book both from a storytelling perspective and a mental one?

Yeah, it's somewhat taxing to write "The Walking Dead" and I think it's somewhat taxing for Charlie to draw "The Walking Dead." These are not the kind of things Charlie and I are used to dealing with in our everyday lives, so it's a little difficult, but that's why I write "Super Dinosaur." I can take a break and spend a day or two with a nine foot tall Tyrannosaurus rex shooting missiles out of robotic arms and it's all better and I don't cry anymore.

While Kirkman has taken the series in very dark directions in the past, nothing compares to what he has in store for #100

Is that how you generally work by focusing on "The Walking Dead," "Invincible" or "Super Dinosaur" for a certain number of days and then moving on to the next?

I bounce around. It's not structured at all. Sometimes I'll work on all three in a day and sometimes I'll work on one of them for a week or two. I know it does help me to move from those different stories and different kinds of genres and moods. I do exaggerate a little bit, it's not completely depressing to write "The Walking Dead," but there have been times where I've written nothing but "The Walking Dead" for a solid week and at the end of that week I'm like, "Ahh, I'm just not happy and I don't know what's going on." Then I realize like, "Oh, yeah, you've been in this world and it's affecting you."

That's one of the most impressive things about your career, how you move around from genre to genre, but still keep that Robert Kirkman feel throughout all of them.

[Laughs] I don't know what that is, but thanks. A lot of creators have that kind of book they like to do and that's the thing they do for the entirety of their career, something that's really racy or something that's really action heavy. I like all different kinds of stories and don't really like doing anything that's similar. I think "Thief of Thieves" is the closest thing I've ever done to "The Walking Dead" and it's nothing like "The Walking Dead." I like being able to flex different muscles and tell different stories. I also enjoy working on multiple projects and I don't think I could do as many projects as I do if they were similar in any way because I wouldn't be able to keep them all straight.

It's like with directors, some will stick with one genre, but then you have guys like Robert Rodriguez who will jump around and do a little of everything.

I'll take comparisons to Robert Rodriguez all day long.

Back to "The Walking Dead" #100 specifically, you've got variant covers by Todd McFarlane, Marc Silvestri, Frank Quitely, Sean Phillips, Bryan Hitch, Ryan Ottley and Adlard. Was it difficult lining all those guys up?

There were a couple people I asked that just couldn't fit it in their schedules. I really wanted to get a Fiona Staples cover, but she wasn't able to work it out. I'm happy to have her focus on "Saga," I think that's an amazing book. I know all these guys because of their relationships with Image, I asked them and they were kind enough to agree to do it. One of the things I'm trying to do with those variant covers is, everyone that's doing a variant cover for "The Walking Dead" #100 is either intimately involved with Image like Marc Silvestri and Todd McFarlane or are working on one of the big new books that are coming out from Image. There's Frank Quitely who's doing "Jupiter's Children," Bryan Hitch who's doing "America's Got Powers," Sean Phillips who's doing "Fatale." I wanted to show a spotlight on just the awesome level of talent we have doing stuff at Image, group them together under the "Walking Dead" spotlight and just turn it into a celebration of what Image does. And then I got Ryan Ottley, not because of his talent but because he's my friend.

I have to ask, why go with a chromium cover as well?

Why not a chromium cover? I've got to tell you, I've been trying to do a chromium cover for years. I wanted to do a chromium cover for "Invincible" #50, but when I did the research I found out that the company that developed the chromium cover technology went out of business. They owned the patent and kind of took the technology with them, so we found out recently that a new company bought that patent and was actually able to produce chromium covers. Once I found out about that, I was like, "Ah, this is sweet, I'm totally doing this." I do almost everything because I want it, because I'm a fan and I love "Generation X" #1 and "Prophet" Volume 2 #1. Chromium covers are totally cool and I've been dying to have one on one of my books and I figured, you know, why not? They look awesome, just wait.

I just saw online that "Hardcore," which was originally solicited as a Pilot Season one-shot, is finally coming out from Top Cow. Can you talk about why that was delayed for so long? Was it an art thing or a writing one?

I hate to point fingers, but it was a little bit of both. Brian Stelfreeze had a window to do that book and I missed it by a little bit. Because I missed that window, it took him a while to be able to get around to doing it. It was a miss on everyone's schedules. But, I will say, I'm happy the book is coming out. Looking over it, I couldn't imagine anyone else drawing it. He's done an absolutely amazing job and there's some action bits in this issue that are just amazing to look at. He really is one of the best comic book artists working today. I think it's really come together and I'm really proud of it.

News also got out that "Thief of Thieves" is being developed for AMC. I know you've said before that you don't develop a comic with another medium in mind, but considering this one has a TV-like writer's room set-up, was the idea of a TV series around earlier on in the process?

The issue features nine different covers by Image creators including Marc Silvestri, Todd McFarlane, Ryan Ottley and more

Look, it's something I pitched to AMC at the same time as developing the series, so they definitely happened concurrently, but "Thief of Thieves" is no less intended as a comic than something like "The Walking Dead" or "Invincible." I'm fortunate enough to have a relationship with AMC where they can get a look at stuff early on and I can sit in a room with them and explain what the comic series is going to be. I think anybody who thinks that anybody creates a comic as a television pitch on paper doesn't realize how simple television pitches are and doesn't realize how hard it is to make a comic book. I've seen some of those accusations thrown around and it cracks me up. "Thief of Thieves" is a book that I'm totally dedicated to. I'm actually working with the writer's room on [the] second and third story arcs right now and we're plotted all the way up to issue #25, so it's something I'm very into for the long haul. Whether the TV show actually makes it to air or not, I know there's going to be a "Thief of Thieves" comic book for a good long while. The intention was always to have it be a comic.

Will you have a similar role on the "Thief of Thieves" show that you do on "The Walking Dead?"

We're still working all that stuff out. Right now, the "Thief of Thieves" show is in the development stage which means we're developing a script for a pilot. Chic Eglee is writing it, once AMC reads that pilot they'll decide if they want to shoot it and then once they shoot the pilot they'll decide whether or not they'll turn it into a full series. We're quite a few stages away from this actually being a go and if it happens, I'm definitely open to being as involved in the show as I am in the "Walking Dead" show, but we'll figure out later how that will work out in my schedule.

Considering their episodic nature and the amount of writing that goes into both, why do you think more comic writers don't go into TV?

I think that there's a lot of comic book writers out there, and I would count myself among them, who are people who grew up wanting to write comics and are completely content writing comics. For me, I was kind of [dragged] kicking and screaming into television writing. It's been remarkable to me how similar it is and I like it, but I can say with absolute certainty that comics is my first love and if I had to chose between the two, I would definitely chose comics. It's the medium I've fallen in love with. It's great that the transition is so easy and the two mediums are so similar, but comics are totally awesome.

"The Walking Dead" #100 written by Robert Kirkman and Charlie Adlard drops with nine different covers from Image Comics on July 11th.