Question: After was an episode of The Walking Dead written by the comic book writer who also created what other series?

Context paragraphs:
Robert Kirkman: Robert Kirkman (born November 30, 1978) is an American comic book writer best known for creating "The Walking Dead" and "Invincible" for Image Comics, in addition to writing "Ultimate X-Men" and "Marvel Zombies" for Marvel Comics.  He has also collaborated with Image Comics co-founder Todd McFarlane on the series "Haunt".  He is one of the five partners of Image Comics, and the only one of the five who was not one of its co-founders.

List of The Walking Dead (TV series) characters: "The Walking Dead" is an American post-apocalyptic horror television series developed and executive produced by Frank Darabont.  It is based on the eponymous comic book series by Robert Kirkman.  The following is a list of characters from "The Walking Dead" television series.  Although some characters appear in both places, the continuity of the television series is not shared with the original comic book series.

The Walking Dead (video game): The Walking Dead (also known as The Walking Dead: The Game and The Walking Dead: Season One) is an episodic interactive drama graphic adventure survival horror video game developed and published by Telltale Games.  Based on "The Walking Dead" comic book series, the game consists of five episodes, released between April and November 2012.  It is available for Android, iOS, Kindle Fire HDX, Microsoft Windows, Mac OS X, PlayStation 3, PlayStation Vita, Xbox 360, PlayStation 4 and Xbox One.  The game is the first of "The Walking Dead" video game series published by Telltale.

After (The Walking Dead): "After" is the ninth episode and mid-season premiere of the fourth season, and 44th episode overall of the post-apocalyptic horror television series "The Walking Dead", which aired on AMC on February 9, 2014.  The episode was written by Robert Kirkman and directed by Greg Nicotero.

The Walking Dead: A New Frontier: The Walking Dead: A New Frontier (also known as The Walking Dead: Season Three) is an episodic graphic adventure game based on Robert Kirkman's "The Walking Dead" comic book series developed by Telltale Games.  It is Telltale's third season of its "The Walking Dead" series, with the first two episodes released on December 20, 2016, and a retail season pass disc edition planned for release on February 7, 2017.  The game employs the same narrative structure as the past seasons, where player choice in one episode will have a permanent impact on future story elements.  The player choices recorded in save files from the first two seasons and the additional episode "400 Days" carry over into the third season.  Clementine (voiced by Melissa Hutchison), who was the player's companion during the first season and the player-character in season two returns as a player-character along with another player-character, Javier "Javi" Garcia (voiced by Jeff Schine).

Fear the Walking Dead: Flight 462: Fear the Walking Dead: Flight 462 is a 16-part web series based on the television series "Fear the Walking Dead".  The series premiered on October 4, 2015, on AMC's official website.  It also aired as promos during "The Walking Dead" season 6.  The web series tells the story of a group of passengers aboard a commercial airplane during the earliest moments of the outbreak.  Over the course of the series, the plane and the lives of its passengers are put in jeopardy once they discover an infected traveler.  Two of its characters, Alex and Jake, are introduced in "Fear the Walking Dead" season 2, episode 3 "Ouroboros".

The Walking Dead: Season Two: The Walking Dead: Season Two is an episodic interactive drama graphic adventure game based on "The Walking Dead" comic book series developed by Telltale Games.  It is the sequel to "The Walking Dead", with the episodes released between December 2013 and August 2014, and a retail collector's disc edition planned at the conclusion of the season.  The game employs the same narrative structure as the first season, where player choice in one episode will have a permanent impact on future story elements.  The player choices recorded in save files from the first season and the additional episode "400 Days" carry over into the second season.  Clementine, who was the player's companion during the first season, is the player-character in "Season Two.

The Walking Dead: Michonne: The Walking Dead: Michonne is an episodic interactive drama graphic adventure survival horror based on Robert Kirkman's "The Walking Dead" comic book series by Telltale Games.  Taking place between issues 126 and 139 of "The Walking Dead" comic series, the game shows events of what Michonne was up to during her temporary departure from the group of survivors led by Rick Grimes in the midst of a zombie apocalypse.  Samira Wiley voiced Michonne in the game.  The three-episode series was released between February and April 2016 for personal computers, PlayStation 3 and 4 and Xbox 360 and One consoles, and on mobile devices.

The Walking Dead: Rise of the Governor: The Walking Dead: Rise of the Governor is a post-apocalyptic horror novel written by Robert Kirkman and Jay Bonansinga and released October 11, 2011.  The novel is a spin-off of "The Walking Dead" comic book series and explores the back-story of one of the series' most infamous characters, The Governor.  "Rise of the Governor" is the first in a trilogy of novels.  "The Walking Dead"'s fourth season utilizes plots from the novel, the Chalmers family in particular.

The Walking Dead: Road to Survival: The Walking Dead: Road to Survival is a role-playing game for Android and iOS, based on the comic book series "The Walking Dead" by Robert Kirkman, as well as the story of "The Walking Dead" TV series writer Jay Bonansinga.  "Road to Survival" was developed by Scopely and co-created with IUGO Mobile Entertainment.

Supporting paragraphs: After (The Walking Dead) Robert Kirkman
Answer: Invincible