Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: World War Z
From the horrific images of armies crumbling under endless tides of graying, mindless ghouls to the insane tale of the French military's battle against the zombies in the Paris Catacombs, World War Z has no shortage of chilling apocalyptic imagery. And that's not even getting into the hair-raising, often tragic tales the various survivor interviews weave. And the bomb that tears your lungs out through your mouth. Which actually exists. And which doesn't do anything against the zombies.
North Korea. Most of the first half of the book is horrific, but North Korea in particular...it's the fact that even twenty years on, nobody knows what happened to them all. From there it has to make you wonder what would happen if they are all zombified in hiding, and what would happen if they ever got out.
This fanfic does a good job of giving you the idea of what happens to the North Koreans. The poor man left in the bunker....
It might not be too bad. 24 million NKoreans zombies at most, minus all the ones no longer viable, plus the fact that we know what to do now... There'd be a bit of initial devastation in the neighboring countries, but it's certainly containable. Probably best to start walling the place up now, though.
They already did it by themselves.
Even if the North Koreans aren't infected, it'd be pretty nightmarish. At least living on the surface they have some hope of escaping across a border or growing some food for themselves; imagine how much worse it'd be underground, where the dictator controls all the food, water and air. Especially if the stockpiles start running low before the ones in charge are ready to leave...
The story of one of the men that has to go down onto the sea floor to find any large groups of zombies that are still wandering around under the sea. He comes across a wreck from the war, goes down to check it, and falls down through the floorboards, into a room full of zombies. They all grab at him with their arms but he's saved by the fact that he's wearing one of those old-timey diving suits.
Comes with a Suspiciously Specific Denial on the interviewee's part that implies recurring nightmares. "If I ever had a recurring nightmare, and I'm not saying I do, because I don't, but if I did, I'd be right back in there, only this time I'm completely naked... I mean I would be". In-world example?
Divers working on offshore rigs were occasionally ambushed by zombies. Some were torn apart, others were killed by the bends as they tried to escape.
The story of the war against zombies in the sewers of Paris.
North Platte being invaded by a horde of zombies.
The survivors in Canada turning to cannibalism out of desperation.. The interviewee did say the soup smelled good, though... "By Christmas Day, there was plenty of food."
That entire segment counts. It's downright horrifying to see how a camp of normal people managed to devolve into desperate, paranoid psychopaths, starving and freezing to death.
Alang, India. People attempted to swim out to ships and could see as people right next to them were dragged under by submerged zombies. Many were trapped between the zombies coming from inland and the underwater ones.
The truckload of infected refugees heading to Kyrgyzstan.
The parents killing their own kids in the church in the Midwest.
The fact that the scene is described (or, more accurately, acted out) by someone with the mind of a four-year-old makes it worse. Poor Sharon...
The book before it, The Zombie Survival Guide, is even worse.
The Chapter on a total zombie apocalypse kept one up a few nights. Imagine being the last known humans in a world filled with undead. It combines two things that will freak anybody out: Complete isolation/loneliness and zombies.
The part of the guide that has recorded events of zombie contact had some pretty scary ones - the one where an entire ship and the slaves chained in lines it were zombies pretty much lampshaded it by explicitly telling you to imagine the horror of the possibility of being a slave on the far end of the ship while one on the close side was bitten, killed and reanimated to bite the slave closest to him and repeat the process, watching undeath approach you with each person...
Or the order of Samurai devoted to fighting the undead who required their new members to spend the night locked in a room full of gibbering severed heads.
In the back of "The Zombie Survival Guide" there are blank pages that are laid out like journal, with places to fill in the place, time, location, distance from the person, specifics and the action taken, so the reader can keep track of attacks near them...making it even more like a real survival guide.
Brooks has stated that one of his fears is that of a zombie, a creature that comes for you for no reason, could not be reasoned with, and unstoppable. He neatly conveys this to the reader through one of the stories, where it's described that no human country can be 100% devoted to war (due to elderly, babies and the disabled) while zombies had no such handicap.
The people receiving infected organs via transplants and transforming into zombies days, weeks, even months later.
The implication of all those women being infected after receiving donated eggs and/or sperm is even worse.
Are you thinking that those women got pregnant with zombie fetuses? Don't worry, according to the zombie survival guide, all zombies are sterile so none of those women could have gotten pregnant. But they all died or turned into zombies though.
North Korea. The entire population moves underground to escape the zombies. Either they're still alive and think everyone on the surface is dead, or they've all become zombies and are trying to dig their way back up to the surface. You choose your own nightmare.
Don't forget the description of fighting in the Catacombs under Paris. Difficult to breathe, unable to see, never knowing when a zombie will grab you and drag you to a watery grave . . .
The baby zombie, still tied up in the carrier, snapping at the woman as she passed by during the crashed pilot's story.