Robert Kirkman is best known for his work at Image Comics, including co-creating the hit series Invincible and The Walking Dead. However, he worked at Marvel Comics for a time. According to Kirkman, however, the experience was not an ideal one.
In an interview with ComicTropes, Kirkman explained his departure from Marvel, saying that working for the publisher felt "restrictive." The writer went on to say, "I was very upset with Marvel Comics -- did not like them. I didn't have a good time there."
Kirkman described his struggles at the company, specifically pertaining to the promotion of his comics and cover art being altered. The tipping point came during a discussion over an Ultimate Marvel crossover he was plotting with fellow writers Brian Michael Bendis and Mark Millar. After Kirkman asked how the book would be collected, he found himself in a heated email exchange with then-Editor-in-Chief Joe Quesada. Ultimately, Kirkman said that he found Image Comics to be more creatively fulfilling, describing it as "a very free environment."
Kirkman is currently a partner at Image Comics; he is writing Oblivion Song for the company. He also returned to the world of The Walking Dead with the recent one-shot, Negan Lives.