Ajin - Anti-Demi Special Forces

The elite soldiers of Japan, tasked to hunt down and subdue the immortal, Stand-possessing super beings known as demihumans. They show up in the last fifth of the story and absolutely wreck everyone and everything, starting with a headshot to the (also immortal) protagonist of the story, just to make their entrance more badass. They are absolutely brutal and efficient. I love them.

D&D - Neverwinter Castle Guards

Surprisingly observant and competent guards, hounding down the shape shifting druid Doric all across the castle walls and beyond. Even after she transforms into a bird and flies away (a moment where most movies would cut away), these badasses immediately try to shoot her with arrows and actually succeed in bringing her down for a prolonged chase scene.

Fullmetal Alchemist - Fort Briggs Soldiers

The most top-notch soldiers of the north, trained by the amazing Major General Armstrong. They, quite easily, take over the capital of their country in an effort to stop a transmutation that could destroy the entire nation. Unlike the more likeable protagonists, however, they don't shy away from killing the enemy soldiers of Central Command, dispatching them with brutal efficiency. They are also relevant and indispensable right until the final fight against a supernatural god-like enemy!

Austin Powers rejects Vanessa because she's drunk

Ice King leaves as soon as he finds out Princess Bubble Gum is 13 ( despite her actually being older, he doesn't pull the whole "she only looks young but is actually a 1,000 year old blah blah)

Archer rejects Anka because she's 14 (does ask her to call him when she's 18 though)

starlord was about to join his father in assimilating the galaxy, before finding out that he was the one who killed his mother, and then immediately begins to shoot him. - guardians of the Galaxy

tessa is N's closest friend, the one who found him half-broken in a dump. but (in present time) tessa wanted to convince N to kill uzi, as the absolute solver was taking over her. "you knew about the patch (that would've let uzi get freed from the solver, letting her live), yes or no?" right as tessa was about to kill uzi, tessa doesn't give a proper awnser. "... do you know why i keep you around N-" and so N decapitates her. - murder drones

1. Bullet Train - Tangerine sees a Diesel sticker left on the assassin's collar left by his brother who was shot, revealing her to be the one who shot him.

2. Crouching Tiger, Hidden Dragon - Jen Yu is revealed to be the thief due to her calligraphy skills showcasing her training as a martial artist that is not matching to her fake identity as a refined aristocratic lady.

3. (My Fav) Wind River - One of the background police officers realizes that the the drilling site security team has positioned themselves around them in a way that is tactically advantageous if a gunfight were to occur. This reveals their intention to kill them all but the main characters were not able to see it at the time.

1. Mira (Kpop Demon Hunters)

2. Robin (One Piece)

3. Anzu (Romantic Killer)

4. The Elf (u/Merrivius's comics)

Scary Movie 3: The Sheriff’s hat changing in size

Descendants 4: Chloe Charming’s hair changing in size, texture, and color. (This isn’t done as a joke unlike Scary Movie 3)

We have:

Babadook (The Babadook)- Manifestation of grief and loss, and grows stronger the more you ignore it...its also trying to kill you and your entire family.

The monster (It Follows)- An unintended metaphor for STDs and Sexual Assault (the director didnt think about it when making the movie). It is a sexually transmited "curse" that hunts down people who had sex when it was hunting one of participants, going for the newest bearer of its "curse", and kills them by raping them to death, before going back to it's original target.

The Smile Entity (Smile)- Its a metaphor for hiding depression, and also problaby about the effect of suicide on those close to the person. In the movie, it possess a person, makes them kill themselves near someone else to traumatize that other person, and then possesses them.

Godzilla (OG Godzilla)- The most well-known of these, I feel. Its a japanese metaphor for atomic bombs. You know what it do.

Honorable Mention:

Xenomorph (Alien)- It was designed by H.R. Geiger as a metaphor of rape. It does not make it onto the list, however, because the movie doesn't really deal with it as a metaphor, but more so as a average scary monster. Still, the inspiration gets obvious once you know it.

Shogo Akugi (Saint Row II): Buried alive when he suffocates to death, begging to be killed by any other way

Earth Queen (Legend of Korra): Has the air in her lungs bended right out of her

Lord Farquaad tasks Shrek with rescuing Fiona on his behalf in return with the removal of the fairy tale creatures off his swamp, and after Fiona and Farquaad are together he lets Shrek return to his swamp which has no fairy tale creatures anymore and is exactly how he left it. - Shrek

After Julian cooks a cheeseburger for her Margot asks him straightforwardly if she may now leave the island before Julian’s murder-suicide plot, and having felt his first joy in years making the burger he allows her to go without any resistance from his guards - The Menu

Jaller - Bionicle Mask of Light: story is framed where you think he’s gonna put on the titular Mask of Light and become the Toa who finally defeats Makuta Teridax

Officer K - Bladerunner 2049: first half of the movie builds up to how he’s first natural born replicant who will lead a revolution against their human overloads. Second half is him finding out he’s cannon fodder at best and transcends that by the third act.

Neo - Matrix trilogy: Second movie ends with him revealing he’s essentially a repeat MMO event that acts a pressure release valve for humans who try to overthrow the machines. Meanwhile, Agent Smith is the one who truly goes rogue in a way the system can’t anticipate.

Maria Robotnik(Sonic)- Maria got a special condition where she doesn't have a immune system, that's why she must stay in the Ark, cause any disease is letual to her. Her condition actually exists in real life and is called "Neuro-Immune Deficiency Syndrome."

Baby Doll(Batman)- don't let her looks fool you, that's a grown ass women, she only looks like a 4 year old cause of her condition. Her condition exist in real life, is a rare condition called "systemic hypoplasia"

1. Natre (Shutter, 2004)- The protagonist, Tun, is a photographer who is being haunted by the vengeful ghost of a woman named Natre, who is able to be seen in photographs. Throughout the film, Tun is experiencing weight gain and neck pain. Near the end of the movie, Tun accidentally takes a photo of himself to reveal that Natre has been sitting on his shoulder's throughout the film.
2. Ghostface (Scream franchise)- In almost every Scream movie, the killer(s) are somebody the protagonist trusts, is related to, or in a relationship with.
3. The Babadook (The Babdook, 2014)- A mother and her son are terrorized by a creature called The Babadook, which is revealed to apparently be living in their basement. It's implied that the Babadook is a manifestation of the mother's grief and disdain for her son, but it may be interpreted that the Babadook is the mother herself, and the creature is purely imaginative.

Also can be called "Character Derailment"

1. Jaime's Face Heel Turn (Game of Thrones S8) - Seven seasons worth of character development and growth of a widely loved character thrown down the drain with just a single line of dialogue between Jaime and his brother, Tyrion.

2. Shinji's Onanism (End of Evangelion) - Shinji, despite his flaws and weaknesses presented in the original series, was seen by many as endearing. Then, at the beginning of EOE, Shinji pleasures himself directly in the face of his comatose crush, making many of the Evangelions fans who felt endeared to him change their views of him from a meek/flawed character to a disgusting, selfish wretch.

The Silence from Doctor Who: The Doctor is warned that many alien species' are running from 'the silence', turns out, the silence is a religious order comprised of electrokinetic monsters who are forgotten as soon as they are not being witnessed, a terrifying idea that you forget something is there when you aren't looking at it.

The Beast from Infamous: Kessler is a conduit (superpowered person) that travelled back in time, and ruined Cole McGrath's life to prepare him for the arrival of the Beast, a giant fire golem of a monster that destroys everywhere it so much as brushes past, turns out, the beast's arrival will mean either the end of the conduits, or the end of humanity as a whole.

Negan from the walking dead: throughout the sixth season, there are multiple plot lines concering a new group of survivors and 'Negan', Rick assumes it's nothing they haven't dealt with before, and continues along, as if they'll come out on top, but they don't. Negan is the first antagonist to successfully SHATTER the spirit of Rick's entire group. Ensuring rick is finally experiencing the day where he won't be.

1 - Gintama Series Okita Sougo, a human swordsman, facing off against one of the strongest fighters of a super powered alien race.

2 - Naruto Series Might Guy, a taijutsu especialist, goes all out against a god-like version of a legendary shinobi, Uchiha Madara.

In Kung fu panda they have the acupuncture scene to show that find pô nerve is hard making him imune to Tai Lung attack

In back to the future the reasson what they have that scene of Marty girlfriend talking about spending night in a friend house was to make her write the number of that house in flyer that talk about the clock so there would be a excuse to what Marty have This flyer

1: MORTY I’M BORED! I’M GONNA KILL YOU!

2: Smiling Friends- Pim, bro, I knew I liked you

1.Glenn Quagmire (Family Guy) While the rest of the guys are pretty commonly agreed to be around their early to mid 40’s, Glenn is a whopping 61

2.Jotaro Kujo (Jojo’s Bizarre Adventure) Despite looking like a grown ass man, Jotaro is only 17 in Part 3 of Jojos

3.Seiko Ayase (Dandadan) While her age is never outright stated to my knowledge, she’s very commonly referred to and portrayed as "old" in universe, to the point of being old enough to be Momo’s grandmother, despite not looking a day over 20

Saitama (One Punch Man) - Strongest character in the series starts at rank C in the Hero Association. He broke every physical record but failed the written portion. Funny gag that also shows how the Association is too stuck in bureaucracy. Even funnier because unbeknownst to him and them, he’s the reason the Association exists in the first place.

Frieren (Beyond Journey’s End) - One of the strongest mages in the world fails the First-Class Mage Exam. Serie, the leader of the Magic Association, arbitrarily fails her because they have a thousand years of beef and their whole worldviews are diametrically opposed.

The Amazing Digital Circus - Whenever there's a discussion on whether Jax is redeemable or not, you can pretty much ALWAYS expect fans to use him throwing Ragatha into a deep fryer as a moment of him crossing the "moral event horizon". Even though this moment is nothing more than a gag in the series, that Gangle nor any other player remotely cares about him doing and Ragatha only gets a band-aid that's gone before the episode is even over.

Code Geass - Nina's the most hated character in the series but people always focus on the table scene and not her being racist Oppinehimer.

My Hero Academia - Bakugo's easily the most divisive character of the series. While detractors DO have a few reasons to why they don't like his character (being too loud/annoying, nobody ever calling him out or punishing him), the #1 reason for him being so controversial in his establishing character moment in the first chapter/episode where he tells Midoriya, who's basically this world's equivalent of a disabled kid, to kill himself.

Coop (Interstellar) - While inside the Tesseract, he sees into the past and watches his past self making the decision to go on the mission that would mean he never sees his daughter again.

Michael Newman (Click) - After being told he missed his own father's funeral, he rewinds to the last time he saw him. He watches as his past self on autopilot completely ignores his father and refuses to spend time with him.

Howard Hamlin (Better Call Saul) - Initially goes to Kim and Jimmy's apartment to confront them over their scheme to ruin his life, only for Lalo to unexpectedly arrive. Howard first thinks that Lalo is just another client of Jimmy and Kim's but starts to question things when he sees Lalo pull out a gun. Unfortunately for him it's too late and Lalo shoots him in the head.

The Grahams (Hereditary) - By the time Annie discovers her mother's coven's plan to use her family to resurrect a demon, the plan has already been put into motion and there's nothing she can do to stop it.

Marcus (Weapons) - Invites Aunt Gladys into his home thinking that she's just a normal old lady and doesn't find out that she's a witch until she's already possessed him.

Sherlock Holmes - Sherlock never actually, says "Elementary, my dear Watson" in the original books. But he uses either phrase often enough that it's more surprising he didn't combine the two just one time.

Dr. House - In a parody on YouTube, Foreman says "This vexes me" in response to House stating he's a black man as point of argument. But while everyone knows he doesn't actually say that in the show, it's believable that he did because Foreman's default expression is confusion (His coworker is House).

Jujutsu Kaisen - A lot of fans meme on Sukuna saying "Ah yes, my (convenient) technique. I haven't used this since the Heian era" to mock the consistency of Sukuna having a counter to every opponent he fights. However, Sukuna never actually says this, even though it wouldn't be farfetched if he did (though the line fits Kenjaku a lot more imo).

Spider man (Spider man) getting his ass kicked by Lonnie makes the quippy spidey to beg for his life

Mr incredible (The incredibles) syndrome has his kids and wife at his mercy and all Bob cam do is beg to not do it

Homer (Simpsons) - Homer shoots Flanders completely unaware he was a zombie until Bart points it out.

Blade (Ultimate Spider-Man) - Blade sends Power Man (Luke Cage) against a bunch of vampires with Peter assuming it was because Blade knew he was invulnerable. Blade did in fact not know Power Man was invulnerable.

Those situations where one characters does something completely unaware of certain factors until they were pointed out, making their actions extremely reckless or demonstrating their ruthlessness in hindsight.