Walking Dead creator Robert Kirkman has said the decision to kill-off one of the show's most-loved characters was "essential" for the ongoing storylines.

During the opening episode of the hit series' seventh season, fans were finally shown who met their end at the hand of Jeffrey Dean Morgan's barbed wire baseball bat wielding bag guy Negan.

Spoiler alert!

Season six concluded with a huge cliffhanger; one of the main characters was beaten to death by Negan, but there was an extra twist waiting for viewers in the season seven premiere when two characters fell victim to Negan's rage; Abraham (Michael Cudlitz) and Glenn (Steven Yeun).

In the comic books, Glenn was always the victim but the TV series has made a habit of changing some events and giving different deaths to different characters. In the comics, Abraham dies by being shot with an arrow in his eye, a death that went to Denise in the last season.

Speaking about the decision to stick to the source material for Glenn's demise, Kirkman said the reasoning was that "there's a lot of material that comes from Glenn's death in the comics."

"While we do try to change things up to keep things interesting for the audience, and for me, this is one that there's so much that comes from Rick, there's so much with Negan, because that character is someone he killed, and definitely Maggie is someone that kind of gets put on the trajectory that affects a great number of stories and a great number of characters moving forward," he told Entertainment Weekly.

"So it was kind of essential that that part of the scene at least remained intact, unfortunately."