Robert Kirkman, No. 1 on The Hollywood Reporter's most powerful comics writers list, has one major regret about AMC's adaptation of his long-running The Walking Dead — and it's a big one.

"If I had to do it again, I wouldn't have done the CDC episode [at the end of season one]," Kirkman told THR of the episode in which CDC doc Edwin Jenner (Noah Emmerich) reveals to Rick (Andrew Lincoln) that everyone is already infected.

The reveal came at an early stage for the zombie drama — which had yet to break out to become the ratings juggernaut it has become in season five, where it continues to rank as TV's No. 1 show among the all-important adults 18-49 demographic.

"It possibly gave away too much information and was such a big change very early on in the series," Kirkman said.

See more 'Walking Dead' Comes to Life: From Comics to the Small Screen

In the comics, Rick and company learn that everyone is infected after Tyreese's daughter, Julie, is killed in what was supposed to be a joint suicide pact with boyfriend Chris. When she reanimates without a zombie bite, Rick and the gang put the pieces together.

"I feel like there might have been a better way to wrap up the first season," Kirkman says of AMC's season-one finale. "It ended up being a fun episode. I love the character of Dr. Jenner and thought Noah did an amazing job. But there were things in that episode that I think seem very much not of The Walking Dead world."

Among the issues Kirkman has with the episode were Jenner's reveal that despite his research, he hasn't been able to find a cure — but that the French may be on to something as their scientists were the only ones who remained in their labs during the outbreak.

"I probably would have changed that stuff," he says. "I've been careful in the comic series to not say what's happening in other parts of the world. It's something that's going to be fun to explore in the spinoff series. But the fact that France is mentioned in that episode and other things like that, I probably would have steered away from that stuff if I had to do it all over again."

See more 'The Walking Dead's' Most Shocking Deaths

As for AMC's Walking Dead companion series, little is known about the project other than that it is likely a prequel and it takes place during the early days of the outbreak in other parts of the world. Casting is underway for the pilot, which AMC hopes to have on the air in 2015 as the cable network puts a renewed focus on scripted fare.

Meanwhile, producers behind The Walking Dead have taken a remix approach to adapting Kirkman's comics under showrunner Scott M. Gimple. While some elements from the comics seep into the series directly, other events may happen to different characters — with a handful of original characters folded into the TV series. Among them: Fan favorite Norman Reedus' Daryl Dixon, who was not in the comics at all.

Kirkman believes Daryl stands out as one of the best changes to The Walking Dead mythology. In terms of differences to the existing characters, Kirkman was quick to praise Melissa McBride for bringing Carol to a whole new level than her comic counterpart.

See more 'Walking Dead' Season 5 Premiere: From the Woods to the Red Carpet

"Carol was extremely different in the comic and I was attempting to tell a completely different story with that character than what we ended up doing on the show," he says. "Carol in the comic and Carol on the show couldn't be more different. I'm really proud of the evolution that that character has gone through. It's one of the best parts of the show. Melissa McBride's performance is absolutely amazing. More than any other character, Carol has evolved in leaps and bounds. You go back to the first season and it's almost like a different actress is playing that character because she's so different. It's been a really remarkable transformation in a show about transformation. That's been a great and welcome change."

The Walking Dead's midseason finale airs Sunday at 9 p.m. on AMC. Click here to check out THR's annual Power Authors rankings and here for the most powerful comics writers, where Kirkman leads the pack.

Email: Lesley.Goldberg@THR.com

Twitter: @Snoodit