This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Resident Evil 6
The boss fight with the mutated Carla Radames. The area you fight her in is very reminiscent of a Silent Hill game! Specifically, that one hospital room in Silent Hill 4 with a very bizarre enlarged Eileen head.
Once you see what he transforms into Simmons rapidly gets creepy. His flesh segments and slides out of the way like a Transformer... BUT FLESH SHOULD NOT MOVE THAT WAY! Bonus points for his human form being so torn apart that his face is nearly unrecognizable.
Hell, the way that boss consumes zombies is the same way. The zombies don't melt or dissolve, they get dismantled like they were made out of legos. Unsettling.
There's a part of Jake's campaign where the Ustanak stalks you while you have to avoid these bugs it sends out to find you. If you don't hide fast enough you'll find yourself getting gored.
Speaking of hiding from the Ustanak: If you hide too much the same place, you're likely to die. Horribly.
Even worse if you have a little chuckle at one of the short conversations that can trigger when hiding in the bin. "Heh, Jake needs to keep his hands to him-OH DEAR GOD THE BLOOD!"
The Rasklapanje's death scene. It involves the creature pinning you down, inserting some sort of proboscis into your mouth, ripping it out, and then another Rasklapanje creature bursting out of your chest.
From a certain angle, it looks more like it bursts out of your face!
The Rasklapanje enemy is a very disturbing-looking creature that is similar to the Ooze B.O.W. from RE: Revelations. It has a disturbing cry, which is eerily similar to a baby. It reproduces by forcing itself via the host leech down your throat, implanting an embryo that subsequently bursts out of your stomach. Whenever encountered, it staggers toward you and makes a groaning noise. They can rip their arms off that can move on their own to send after you as well. Small arms fire doesn't stun it. Perhaps the most frightening aspect of the creature is that it won't stay dead. That's right, if you're not quick enough, they regenerate and pursue you once more and when you do defeat it it doesn't die it just lays there out of energy making that unsettling shriek. But then even more will appear. It also has a nasty habit of ambushing you in enclosed spaces and to really make you panic, it's only attack can instantly kill you if you're not prepared. Probably one of the most disturbing creatures in the series.
The J'avo already look suitably gruesome with their multiple eyes and scarred faces but when they mutate, this gets taken up to eleven. All of the possible mutations are both horrific and dangerous but the scary part is that they are entirely random. You never know what the mutation will be until the J'avo suddenly grow spider legs or transforms into a swarm of mutant bees.
Probably the worst of them is when it gets covered in humongous maggots and blows up when it takes enough damage.
The worst part about them is that they retain their human intelligence. Which means that they aren't compelled to kill people, Yet they still do so entirely because they enjoy it ! Dear GOD !!
The Ustanak. He chases you everywhere, cannot be killed and possesses a variety of nasty weapons which are physically attached to his arm, from a giant metal claw to a machine gun. The chase sequences, where you must escape this brute can be terrifying. Fortunately most of his boss fights are loudly announced by the appearance of several bright red exploding barrels that the game wants you to use against him.
In one encounter with Ustanak, you must use stealth to evade him and some weird insects that will alert him to your location. If he sees you, dramatic music plays then you must find a hiding spot very quickly. If you do manage to hide then there is the incredibly tense moment as Ustanak stomp around inches from your position before charging off. And if he manages to catch you he disembowels you with a collection of huge drills.
The Lepotitsa is a disgusting monster that makes some very creepy noises and looks repulsive with its multiple tumors and split-open face. It's main purpose is to spread the virus and you actually witness it grabbing innocent people and converting them into zombies. It's rather horrible to say the least...
What makes the encounter with this monster even worse is that Leon and Helena release it from underneath the Cathedral, allowing it to infect all the civilians who were hiding inside from the zombies. Nice job breaking it heroes.
Encountering it, or another one, in the cockpit of an airplane is fairly claustrophobic.
'Creepy noises' doesn't make that thing justice: when it's not shrieking like a velociraptor on meth it is Laughing Mad, a distorted, high-pitched, maniacal Laughing Mad. more fuel? When its head is not split open it has its gums and teeth exposed in a perpetual Slasher Smile, and the multiple pores on its body look horribly like big, flaccid breasts!
The Lepotitsa can also instantly kill the player, or least put them into dying status by shoving it's tongue down their throat. Although, that might be more of an example of Squick.
From Leon and Helena's campaign, there's the part when you have to swim a long distance underwater and your health meter turns into a meter of how much air you have left. There are occasional air pockets, but there's plenty of zombies underwater who want to grab you, thus combining the fears of drowing and getting eaten by zombies.
The Shrieker, a mutated zombie with an elongated neck and a giant lung/gullet/bewlap thing, it has the ability to scream to stun the player and call the zombies...most of the time however, this thing is running away from you, screaming in terror. Not scary, but quite unsettling.
If a Whopper successfully grabs you, he will pick you up and just start chomping down on your torso.
The Bloodshot, Spiritual Successor to the Crimson Head. It looks like the lovechild of a Licker and a Regenerator, it is very hard to kill(not only because it is a damage sponge, but because after damaging it enough it will kneel down, exposing its heart, and ONLY if you shoot it in the heart it will die, otherwise it will regenerate and attack again) and deals tons of damage..oh yeah, and any zombie may suddenly turn into one, to rub futher salt in the wound the transformation is more likely if you kill the zombie with a HEADSHOT.
Ubistvo, yet another chain-saw monster, but this chain-saw is organic, growing directly from Ubistvo's arm, and the in-game files explain that the chain-saw is really its heart and ribcage. Ubistvo's rage is terrifying too, being almost as much as an Implacable Man as Ustanak, chasing Ada, Jake, and Sherry all over Waiyip.
If Ada gets knocked off the bus by Ubistvo, Zombies shamble out of the alleys to devour the player as you lie helplessly in the street. In loving first-person view for maximum horror.
Your first look at the open streets of Tall Oaks. Unlike the previous situations where you arrived after the worst part had died down, this time you're thrust into it while the shit is still hitting the fan, and it's backed up by some of the most chaotically terrifying music in series to date. See it here at the 4:00 mark.
In chapter 1 of the Jake and Sherry story, you come across a darkened corridor full of female manikins and a crude mural on the wall of a fearsome face. Nothing attacks you there and no explanation is given for such a place; it's just a bit of Silent Hill-style atmospheric horror.
Leon and Helena's drive through the c-virus cloud. All around you civilians and soldiers alike are succumbing to its effects and turning into Zombies, moaning and shambling pitifully around you. Just moments earlier it seemed like everything was going to be fine for them, and in an instant an entire city died in a single attack. It's one of the most poignant, sobering moments regarding Zombies in the series.
What happens to Simmons when he gets infected with the C-Virus is one of the most disturbing examples of Body Horror the series has ever pulled off. When he first transforms, he bursts into flames and most of his clothes fall away. Lesions begin to grow on his skin, and before you know it, his face and skull start splitting open, letting the audience see into his skull and brain. His body becomes a biological rubix cube, reconfiguring itself into a number of horrifying forms. His second form takes the cake. Its a sort of centaur, but rather than the upper body of a man, most of his spine, internal organs and head sit exposed on top of a dog-like body like a snake standing on its tail. He derails a train with ease, fires shards of his own bones at you like a machine gun and does it while screaming in rage, vowing to kill you. And that's just his warm-up act. Finally, he becomes the Implacable Man for the later half of Leon and Helena's chapter.
When Simmons, in his second form, screams out "How can my Family leave me?" There's something pretty unnerving about his anguished cry while still horribly mutated.
Aside from the aforementioned form, he also transforms into a zombie-like dinosaur with a huge eye in its mouth, and then into some Kaiju-sized housefly/dragon thingamajig that regenerates by assimilating zombies. How does he do that? He jams long tentacles in them, dismantles them like they were made of Lego bricks, and absorbs them.
Long story short, he transforms into the horrific bastard child of a Transformer and an undead Gunther Von Hagens Sculpture.
If you're killed by a zombie while in dying mode, there's a chance you'll be given a very slow animation of it ripping the character's belly open, pulling their intestines out and eating them.
If you die to a dog, it'll drag your character's dead corpse off the screen. You can probably guess what'll happen next...
This is what a Neo-Umbrella employee has to say about Sherry: But it would be great to have that woman he's with brought back alive. She looks good enough to eat. I bet she'd make a great sound under the knife. I'm getting excited just thinking about it. I can't wait to slide my scalpel across her creamy, snow-white skin, cut it open and take a long look at the inside.
The concept art of what Mutant Deborah's face was going to look like originally. To put simply, her face was going to open up like one giant gaping maw. Thankfully it never made it to the final product.
There's a certain quick-time event in the Leon missions, after you finally escape the Rasklapanje bosses — one of them suddenly grabs you while you are passing through a butchering shop, and Helena is powerless to help you, triggering the quick-time event. If you fail it, Leon gets forced into a huge blender and shredded into human mince. Not helped by the fact that the monster responsible promptly topples in afterwards.
If you do beat it, however, you manage to lever the Rasklapanje so it goes into the grinding blades instead.
The cutscene after Chris and Piers fail to stop a C-Virus missile. While Chris and Leon wait for their respective calls to go through, Helena sees the missile over her head, cue Chris shouting "GET THE HELL OUT OF THERE!!!". The missile explodes and just when you think nothing could go wrong, an enormous group of zombies starts attacking the populace while the music plays to emphasize the gravity of the situation.
The Iluzja, aka "Yawn's scarier little brother". It's a giant snake, it has human-level intelligence, it can turn invisible, and the level you encounter it in revolves around you wandering through a labyrinth of dark, filthy apartments and corridors whilst this... thing... is crawling around with you, leading you on, taunting you and randomly springing attacks at you. Adding to it is the Body Horror when it opens its mouth, allowing you to shoot its one weak spot: its teeth wriggle. That is just not right!
"Wriggle" means that it has razor-sharp moving insect claws in place of teeth, something that would make an avid entomologist proud.
What makes it even scarier? Illuzija is a C-virus B.O.W. Just like any other C-Virus B.O.Ws, despite looking like a giant snake, it began as a human being...
For that matter, the same could be said for any C-Virus creation. From the Brzak◊ to the Rasklapanje to the Ogroman, they all were, at one point, human beings. Good God.
We already had 'giant' B.O.W.s like the El Gigante and the Ndesu, but this game gives us the Ogroman, that not only is even bigger that the previous ones(over 30 feet tall), but while the Ndesu and El Gigante still looked mostly human, the Ogroman is horrendously twisted with it bony protusions, twisted skeletal frame, gaping fanged maw and exposed organs sprouting from its back, to make it even worse it is totally impervious to damage aside from said exposed organs, and it's very hard to shoot them. to rub further salt in the wound, you are forced to fight TWO of them at once!
The campaign selection screen can be this. They all are spotlights giving you a glimpse of the monstrous creatures you will have to fight in each campaign ( E.G : Zombies for Leon's, J'avo and their mutations for Chris' , and the Ustanak for Jake's. ). The only exceptions are Ada's, which shows a spider for some reason, and the tutorials, which just overlooks a street with no spotlight. One may expect a Jump Scare from each and every single one of them. They don't.
Although for some, it's more of a Crowning Moment of Awesome, Piers' transformation upon injecting the C-Virus into the stump of his lost right arm. Creating essentially an arm-mounted railgun that fires from his own regenerating life force, you can see the limb pulasting and throbbing as if it was nothing but muscle and organ taking a whole new form. Even worse, as time goes along part of his body becomes shredded, the skin on the right side of his body wearing out as his internal organs are wholly visible.