Invincible is a monthly comic book published by Image Comics. Invincible was created by Robert Kirkman and Cory Walker. Before coming over to Image comics Robert Kirkman had self published a book called Battle Pope (currently being printed at Image) with an artist by the name of Tony Moore. While working on Battle Pope Robert had worked with Cory. They pitched Invincible when they were asked to create a book for image's new superhero line. They both got their start at Image Comics when they were trying to pitch a book called Science Dog (which still hasn't seen print). Cory had done a pinup of SuperPatriot which the top brass at Image liked. They asked Robert and Cory to do a new Super Patriot miniseries. During which time Robert also did a book called Tech Jacket.

Around issue 7 Cory was having some scheduling problems which were keeping him from staying on a monthly schedule. Invincible's release was sketchy at best (only 6 issues were released its first year after a January start date). It looked like the book might be canceled. Luckily, Robert came across another artist on PencilJack.com. Ryan Ottley had been doing a strip call Ted Noodleman Bicycle Delivery Boy (Available in TPB through Alias Comics) and various other projects for Digital Webbing. Robert liked his stuff and asked him to come over. Ryan took over with Cory's blessing and has been the artist on Invincible ever since. Cory is still very much a part of Invincible contributing ideas, character designs, and the occasional cover.