These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alas, Poor Scrappy: In-universe example: Rex Splode. Few people would have admitted to liking him when he was alive, but those who knew him were all very much hurt by his death.
Ensemble Darkhorse: The little-seen but hugely popular Allen the Alien. Kirkman has stated that, in his experience with the fandom, Allen is nearly everybody's favorite character.)
He's also Kirkman's favorite character, which is part of the reason why he hardly shows up. Kirkman's well aware that all it takes is a little overexposure to turn the Ensemble Darkhorse into The Scrappy.
Like You Would Really Do It: In issue 63 Conquest appears to have killed Eve. She involuntarily heals herself the very next issue. In issue 100, Mark himself appears to have been killed within the first two pages by Dinosaurus. The succeeding pages show that Dinosaurus killed a clone of Mark, who's completely unharmed.
What an Idiot: During his initial Face-Heel Turn, Nolan is completely shocked that Mark doesn't want to join him in conquering Earth. This after almost twenty years of raising him as nothing less than a good natured hero, making no attempt to even give his son with Blue And Orangemorality growing up. Possibly justified in that, even if he didn't realize it yet, his time on Earth had changed him for the better.
What Do You Mean, It's Not for Kids?: Usually the 'Allen the Alien' issues begin cutting away from a sex scene, with Kirkman explaining he wants to keep the comic family friendly. These issues tend to contain some of the most violent battles in the comic, the first having Allen's intestines and eye ripped out. Yeah, real family friendly Kirkman.
It's possible a Shout-Out to Moral Dissonance of the old Comics Code, which was very lenient towards violence but extremely conservative in regards to sexual content.