The Walking Dead has one of the most passionate fanbases in comics history that prides itself in its attention to detail, but according to series creator Robert Kirkman, one obvious inside joke basically went over the entire fandom's head and drove some to madness.
The 75th issue of The Walking Dead is exactly what you would expect from the comic book. Rick is melodramatic, Michonne is the sensible voice of reason, and, you know, there are zombies about. After the letters to the editor, though, there's an extra couple of pages of a decidedly different story where Rick wakes up with a bionic hand and becomes a superhero. The story might seem out of place at first, but as you read it, it's clear that it's meant to be something of a joke — a joke that Kirkman himself openly made about The Walking Dead when it was a much newer comic.
Speaking to Entertainment Weekly, Kirkman recounted how, when issue #75 first came out, a number of The Walking Dead seemed not to have caught onto the jokey, Elsewords-esque pivot that was actually meant to be a response to the idea that The Walking Dead was never going to last.
Very early on in the series I started getting letters where people would say, "You say you're going to do this book for a really long time, but this idea doesn't seem to have any legs." My response as a joke was, "Oh, we're going to this until issue 75, and then I'm going to run out of ideas, and then I'm going to do an alien invasion and just kind of completely ruin the book. That's when we'll jump the shark and it will be terrible and everybody will hate it."
Kirkman ended up writing that story assuming that people would understand that it was entirely tongue-in-cheek, but that wasn't exactly the case. A number of fans thought that the series had legitimately run out of steam and was being rebooted as a more traditional, superhero-y comic. Kirkman said that he received a number of angry letters explaining how he was ruining his own book, but, as per usual, the writer brushed off the haters and kept doing his thing.