Galvatron: The Autobots are acting like madmen! Rodimus Prime: It's a madness plague, Galvatron. If one of those Transformers touches you, you're infected. Galvatron: You're lying! Rodimus Prime: Fine. Whatever makes you a happy Decepticon. Just watch your rear thruster.
Higurashi: When They Cry arguably deconstructs this trope since the main characters always suffer from it. Through most of the arcs, no one figures it out, and as a result, anywhere from more than half of to the entire cast winds up dead at the various ends.
Whether shown or not, every arc ends with the entire town dead as the military rolls in and kills everyone, ostensibly to stop a sudden mass outbreak of Hinamizawa Syndrome.
Kai turns it straight again when the heroes learn about the plague in question and conquer it with The Power Of Trust.
Further, one character does have it figured out in every arc (and a few more know about it but don't find out about specific instances until too late). Unfortunately, by not fighting against it aggressively enough she produces the same effect as if she hadn't known about it at all, which is to say none, and still gets to watch her friends descend into violent madness.
It's actually more of a Paranoia Plague than a Hate Plague, with a side order of hallucination, but it gets the job done.
In Read or Die The Television Series, one Villain of the Week uses two kinds of sounds to protect his base as the heroines try to infiltrate it, both of them out of the range of normal hearing: one is a subsonic hum that enhances depression and melancholy in people who are already disposed to it, and the other is a supersonic hum that makes more excitable people angrier and more irritable.
Yubel uses this in duels to great effect in Yu-Gi-Oh! GX. While she's on the field as a monster, she can force monsters to attack her; she takes no battle damage, and inflicts the same damage to her opponent in retribution. She calls this effect "Nightmare Pain." Shortly after Yubel reveals herself in Season 3, Judai's cloest friends are also infected with a Hate Plague against him, which was quite effective in bringing out his Superpowered Evil Side, especially when followed by their apparent deaths.
In the first Star Trek manga, a man and a woman who were once lovers (and who had a bit of a falling out) come on board the ship. They end up making all the men and women on board turn against each other merely from their presence.
Also Transformers-related, one issue of Marvel's Generation2 comics featured black energy goo beings that induced and lived on other creatures' aggression.
Inverted in the Hellblazer arc "The Red Right Hand", in which the plague makes its victims incredibly empathic. Unfortunately it takes hold in Glasgow and so everyone begins to share one another's guilt and misery, culminating in mass suicides.
An alternate version of the New X-Men, set in the House of M universe, dealt with Wallflower, a mutant with pheromone powers, causing Sooraya to engulf her best friend Jubilee in a sandstorm that likely would have shredded her body to its bones if given time.
In The Savage Dragon #55, a massively powerful mind-controller unintentionally sends everyone in Chicago into a murderous rage the moment he steps out of his bunker.
In a Star Trek: The Original Series comic a long time ago (it came with a vinyl record to read along with) wherein an alien Catgirl's pet, a Waul, gets loose on the Enterprise. It's agitated yowling makes everyone on the crew start sniping at each other, and the closer they got to the critter the worse it got. Once it was reunited with its mistress, it was happy and purring again.
During the Blackest Night, Psycho-Pirate used these on Smallville. Horror ensued as his mask's abilities to influence any nearby target to near-suicidal hatred, uncontrollable fear or demented avarice ensued, heightening minor feelings to killing urges.
A new (non-Hitler) Hate Monger appears in a Punisher story as the leader of a racist organization. The Punisher infiltrates the group, but discovers that his final initiation is to beat a Hispanic reporter investigating the group to death. Unfortunately, by then he's succumbed to the Hate Monger's Hate Plague and he goes through with it. Doubly unfortunately she was the girlfriend of the Punisher's current tech guy. Needless to say, there was a falling out and a rare bout of guilt for Frank Castle.
In Astérix and the Roman Agent, Tortuous Convolvulus has the ability to sow mistrust (indicated by Speech Bubbles gaining a green background) that quickly escalates into shouting and fistfights.
He complemented the power of causing mistrust and discord by his presence alone (he didn't have to say or do a thing to start a fight between Caesar's advisers) with a good amount of mundane skill in psychological warfare and sowing mistrust and fear. He also had been sentenced to death at the Colosseum, and was alive at the beginning of the book due to making the beasts attack one another.
In Judge Dredd East Meg One used a literal Rage Virus as a precursor to invading Mega City One.
And more recently the remnants of East Meg One (which was mostly wiped out after aforementioned invasion attempt) had another go with the Chaos Plague, which also caused eventual death. This one worked slightly better, relatively speaking, killing about 350 million (!) in the end.
In Archie Comics, a flower putting off purple "bad vibe lines" caused nearby people to start acting meanly and selfishly. It, naturally, got passed around town for a while during the course of the story, making as many people as possible get into shouting matches. Probably not the only time such a story happened in that series.
The eponymous Black Gas of Warren Ellis' Zombie Apocalypse -style comic operates via progressive brain damage, eating away at the parts of the brain responsible for people's inhibitions.
The Wonder Woman villainess Genocide has powerful energy blasts. Anyone lucky enough to survive the explosion gets consumed by rage and paranoia.
Ares tends to incite rage in order to start wars.
Batman: Jekyll and Hyde had a drug that was described as unifying the conflicting halves of a person's identity. Apparently everyone secretly wants to murder, torture, and/or cannibalize the nearest primate. Huh.
In Astro City, when Black Velvet is mortally wounded by Jitterjack, her body releases black energy that infects the populace and starts a riot.
In the earlier Sonic the Hedgehog comics, evil wizard Ixis Naugus can amplify peoples' emotions. This is hinted to be the driving point for the Great War between the Mobians and human-esque Overlanders, and then the Mobian/Robian civil war.
More recently, he used that same magic on the citizens of New Mobotropolis, magnifying their mistrust of NICOLE - following her stint being brainwashed by the Iron Dominion - into full-blown paranoia, so that they will view her as a threat, and him as their "savior".
The plot of Crossed is centered on a virus that causes its victims to turn into predatory psychopaths.
In Darkwing Duck, the Phantom Blot has created an inky mind-altering substance to create new rogues in St. Canard which is also used to control the populace briefly.
In the grand finale of Grant Morrison's run on JLA, this turns out to be the nature of Mageddon: a hate plague on a global scale that eventually causes all sentient life on a given planet to wipe itself out.
The Spider-Man storyline Maximum Carnage has Carnage's partner Shriek increase the hatred in everyone in New York to start mass riots throughout the city.
In the first Titans series, the Gargoyle slowly began to spread his influence on the Fab Five to the point that Nightwing sealed himself off in a cave because he was sick of being compared to Batman. After being trapped in a Lotus-Eater Machine dimension and reverted to their teenage forms, they assumed apologizing would get them out, until Roy Harper realized they were going in circles and admitted that real friendship is about being honest with your friends when they're acting like assholes and glorifying everything your friend does is not helping. Roy got the point across by punching Nightwing in the face, who seemed to be the focus point due to the Gargoyle's immense hatred of him.
The DC Comics miniseries Legends has Glorious Godrey use his powers of persuasion to manipulate the average citizens of the DC Universe to fear and hate the world's superheroes.
One of the "non-lethal" weapons employed by the good guys at the end of Mystery Men is a ray (the Blame Thrower) that can cause angry arguments amongst whomever gets hit with it. A rare case of the protagonists employing such a tactic as psychological warfare.
Serenity: The Reavers (murdering, raping madmen who terrorize the fringes of the universe small star cluster/ solar system) are revealed to be the victims of a government-sponsored lotus drug gone bad. It was meant to weed out aggression in the population. Instead it made the majority of the population so passive that they couldn't even be bothered to take basic measures to continue living, while it became a Hate Plague for a fraction of a percent of the population. They proceeded to wipe out whoever was left, and then start recruiting.
Utilized by Loki through his scepter in The Avengers to make the already volatile team turn on each other so as to distract them from his assault and unleash the Hulk upon S.H.I.E.L.D.'s helicarrier.
In Apollo 13, the astronauts getting increasingly snappish with each other is discovered to be induced from the high carbon dioxide levels in their cabin. They then have to work together to prevent the CO 2 from getting any higher. (Doesn't count as a Real Life example, because the real astronauts confirmed the arguments were made up by the film for Rule of Drama.)
The Cunning Man from I Shall Wear Midnight is an embodiment of this. He's the ghost of a witch hunter whose hatred for witches is so great, wherever he goes people become more suspicious and angry with witches.
In David Moody's Hater and its sequels, a virus causes people to murder their loved ones and anyone else in their path. The local media even calls the infected people "haters."
Played with in Star Trek: A Time to.... It sort of happens on the planet Delta Sigma IV, in A Time to Love and A Time to Hate, only with a twist. The plague isn't really causing the hate and violence- in fact, it's curing the populace of a mind-altering drug that kept them peaceful. Suddenly confronting emotions such as hate and rage for the first time, the Delta Sigma inhabitants can't cope, and old racial tensions erupt into violence. Riots soon spread across the planet.
The entity from "Day of the Dove" (as outlined in "Television" below) figures in the destruction of the Tkon Empire in The Q Continuum trilogy, mainly by inciting war between the outer planets and youths and the elders and the home planet.
In James Tiptree Jr.'s short story "The Screwfly Solution", a mysterious plague spreads outward from the equator, turning male sexual urges into murderous violence against women.
In Cell (the 2006 horror novel by Stephen King) a signal (possibly sent by terrorists) broadcast over cell phones strips away the higher functions of the brain, leaving just a state of murderous rage. The infected then progressively evolve into an organized, non-raged Hive Mind and develop psychic powers.
Another Stephen King example, 1987 novel The Tommyknockers. A crashed spaceship begins to effect the area around it, causing the inhabitants of the nearby town of Haven to start changing, mentally and physically. During the mid-point of their transformation, they begin seeking out and killing those who have done them wrong, regardless of whether that wrong was real or simply perceived. The residents of Haven then progressively evolve into an organized, non-raged Hive Mind and develop psychic powers. Hmm . . . y'know, that sounds familiar.
Stephen King also used the idea in Needful Things, where the Big Bad, Mr. Gaunt (a demon, if not the devil himself) manipulates the town into destroying itself through a series of escalating "pranks". Evidently Mr King likes this trope.
The novel One Rainy Night by Richard Laymon is about a bizarre black rain that causes Ax Craziness in everyone who gets wet.
Similarly, the Brian Keene short story "Purple Reign" features purple rain that does the same, though this Hate Plague affects animals as well as humans.
In The Long Last Call by John Skipp, the Devil goes to a strip club, where his tainted fifty dollar bills inspire murderous rage in the employees. Yes, even the girls. Especially the girls.
The One Ring in The Lord of the Rings has this effect, turning people against one another by playing on their lust to use its power, particularly on Bilbo and Boromir. This was shown well in the film adaptation in a shot which showed the arguing Council of Elrond reflected in the Ring as fire blazed within it.
Also the flashback to Deágol and Sméagol finding the Ring while fishing. Within minutes Sméagol (Gollum) has killed his relative in order to possess the Ring.
Sam proved resistant when he used it to rescue Frodo, since he had no desire for power whatsoever.
Faramir was also resistant. Well, in the original text, anyway.
Even in their cases it still took a fair bit of willpower.
Boromir was exposed to the ring far longer than his brother; Tolkien may portray one as a "better" man, but the younger brother had been exposed for only hours, not days and days.
Boromir showed hints of being tempted during the council scene, immediately upon being faced with the ring.
The Ring works on ambition as well as hate. Faramir just wanted to live his life, and if he happened to be some sort of hero it would only be because he had to. Boromir wanted to be a big famous hero, cast down Mordor, restore Gondor and Arnor to their former glory. Certainly not a bad ambition, but the Ring can latch on to that to start its Hate Plague after taking hold.
Morgoth in The Silmarillion was capable of sending these off with his will eventually, although he was just as good at using rumor and misdirection to accomplish the same end without sorcery.
Able Team #8: Army of Devils. A drug capable of creating instant rage in the user is smuggled into Los Angeles, in an attempt to create a race war in the United States.
One of the Dinotopia companion novels (The Maze) includes a heavier-than-air Hate Plague-inducing gas as one of the obstacles en route to the center of the titular maze. The raptor of the trio is driven out of the group first and decides to go up the walls, clearing his head. He then manages to take advantage of the gas' effects to dare the other two to stay together and not kill each other until they get out of the hazard zone.
In The Wheel of Time, the dagger from Shadar Logoth is so tainted with evil that his carrier becomes paranoid and hateful, and then starts to infect other people.
Padan Fain, a recurring villain partially possessed by the spirit who created Shadar Logoth, also has this effect- people who spend too much time in his company become increasingly paranoid, ill-tempered, and generally corrupt. When he gets the dagger back (another character carries it for a good chunk of the early books) his powers are increased dramatically.
Kyr Bulychev's book The Purple Sphere is about an artificial virus (stored in the titular container) which causes unnatural hatred in anyone infected. The developers got infected. They killed each other off, the rest of their planet's biosphere evolved into a Deathworld.
The Dark by the same author uses a more supernatural version of the same trope, with similar results.
The god of war Ares in Percy Jackson and the Olympians radiates an aura that makes people around him more susceptible to violent impulses. It's not quite a weapon, but it means the characters have to be more careful around him since he is always looking for an excuse to start a fight.
Brian Keene's Jack's Magic Beans takes place in the same universe as the aforementioned "Purple Reign", but this time, the Hate Plague has no detectable cause and doesn't appear to affect animals or people who take Prozac.
Milder example in Galaxy of Fear: The Planet Plague. Tash's illness makes her more irritable and impulsive, and gets her to dwell more on thoughts of Revenge - and negative emotions make it progress faster and will speed her transformation. Calming herself and focusing on positive emotions helps with the symptoms, but doesn't cure her.
"Your body has a certain temperature, and usually it creates certain kinds of chemicals in your blood, your brain, and all the different parts of your body. But when your body changes - as when you are angry, or sad, or when you are sick - your body temperature changes, and your brain sends signals to produce different chemicals. Somehow this virus affects those signals and feeds off of them."
H7D3 in the Black Tide Rising series ultimately turns the infected into feral, non-sapient cannibalistic animals who are human only in a biological sense and will attack anything that draws their attention.
The Spider-Man novels "Carnage in New York" and "Goblin's Revenge" feature Spider-Man fighting to prevent a virus that causes anyone exposed to it to fall into a murderous frenzy from being unleashed on the public, first by Carnage, and then both Carnage and a new Green Goblin who's actually the Chameleon in disguise.
A Nightmare on Elm Street: Perchance to Dream has the main character use his powers to suppress the dreams of the townspeople, in order to protect them from Freddy. Unfortunately, this has the unintended side effect of gradually causing everyone to become violently unstable, and begin lashing out at random. A few incidents mentioned by the police include a student stabbing a teacher in the eye with a pencil over a bad grade, and a man shooting his wife because she was "vacuuming in a really irritating way".
Walter Jon Williams' Implied Spaces features 'Zombie plagues', nanotechnological infections that drive victims into a murderous rage, and rewrite their brains so they can't be in any other state.
In the Beautiful Creatures, The spell Ridley casts on everyone during Savannah Snow's party amounts to basically this, and it causes everyone in the party to start screaming at each other.
In the second Uplift trilogy the Rothen tried to use a psi-emitter to stir up conflict among the six races of Jijo,
Star Trek: The Original Series, "Day of the Dove": An Energy Being that feeds on hate brings the Federation and the Klingons, who are trying to abide by the peace treaty, into conflict. It goes as far as implanting False Memories so that the manipulated will have an extra source of conflict. An interesting part of this trope in Star Trek is that those who are killed are somehow brought back to life with their fatal wounds healed to fight again. Once they all figure it out the creature is repelled from the ship by laughter. Lots and lots of laughter.
In "The Tholian Web," a Negative Space Wedgie drove the crew of one starship to kill each other, and then begins to drive the Enterprise crew to outbursts of anger.
In "This Side Of Paradise", an anger-inducing sonic broadcast is used to counteract the effects of tranquility-inducing spores.
In one episode, the closer the ship got to an undetected singularity, the more the crew started to freak out, basically giving them a nuclear version of Super OCD.
This is also one of the possible effects of Orion pheromones on other women.
Crusade, the sequel to Babylon 5, had an episode where the crew visited a planet that was boobytrapped with a means of driving visitors into murderous rages. Afterwards, they would have no memory of the event and instead remember seeing a shadowy figure performing the act, leaving the victim unaware they were the actual attacker. Of course, it wasn't really a plague but Technomage nanites.
In episode "Ice", an extraterrestrial parasite causes an Arctic research team, and later the investigating team, to turn on each other by increasing their paranoia.
In "Red Museum", where as part of a Government Conspiracy the children of a town are infected with alien DNA which causes increased violent behaviour.
Used for humorous effect in "Syzygy", in which a rare planetary alignment causes strange behavior in a small town, and even Mulder and Scully begin to snipe at each other; and in "Fight Club," in which a pair of teens cause a Hate Plague to befall anyone who comes into contact with both of them.
Angel had a variant: the touch of a particular vicious misogynist caused any man he touched to hate and attack any woman they came near.
In another episode, the bizarreness of the week causes people to bleed from their eyes and go into a murderous rage about whatever they feel.
One episode of The 4400 concerned an attack by a 4400 who was able to stimulate aggression in men, resulting in a breakdown of discipline at NTAC headquarters.
An early episode of Stargate SG-1 subjected the team to hypersonic frequencies that made some of them very irritable, resulting in a shouting match and a delightfully awkward non-apology apology afterward.
A minor one was caused by withdrawal symptoms from some creepy Goa'uld light in the episode with the same name. Similarly, Daniel's withdrawal from the sarcophagus in Need had him almost shooting Jack in one scene.
The Sarah Jane Adventures had a single-target variation, where anyone who heard or read the name "Clyde Langer" turned against Clyde.
An episode ('Sense and Antisense") of Millennium (the TV series produced by Chris Carter) has Frank Black tracking down a man supposedly infected by a hate virus. At the end we see a photograph of the man posing with military personnel marked "Kigali, Rwanda, 1994".
An episode of The Man From Uncle. ('The Suburbia Affair') centered around a plot like this— the electric lights in a suburban neighborhood vibrated on a frequency that caused the people living there, including our undercover heroes, to become irritable, suffer headaches, and fight amongst themselves. A mob scene was narrowly averted at the town meeting.
The Farscape episode "Crackers Don't Matter" has a highly amusing Hate Plague, causing several characters to become obsessed with ensuring their fair share of crackers, to the point of barricades and gun battles.
One of the Gelliant Gutfright sketches from A Bit of Fry and Laurie features the "Fighting Buttercup," a flower which causes anger and aggression for about five minutes. And then explodes.
Ultra Seven episode 8 has aliens lace cigarettes with a toxic seed that made humans violent. It was all a plan to repopulate the Earth after humans wiped each other out.
In Alphas, one of the Villains Of The Week Matthew Hurly has the ability to release pheromones that causes the people around him explode in homicidal rage.
The "Hound of Baskerville", in the Sherlock episode of that name, turns out to have been a hallucinogenic drug that also functioned as this, giving those it was forced upon images of horrible monsters... and then making them want to murder them.
In the Doctor Who episode Midnight, the Monster of the Week manipulates a group of ordinary humans into coming within a hair's breadth of killing the Doctor by amplifying their fear, suspicion and irritation with his ego into a willingness to commit murder. One of the many unanswered questions from that episode is whether the creature was telepathically manipulating them or whether it was able to do it through mundane psychological methods; it clearly has psychic powers of some kind, but at the point of its near victory it hasn't provoked any reaction from the people that couldn't be achieved simply by playing on the escalating mob mentality.
In The Twilight Zone episode "The Encounter", a racist World War II veteran and a young Japanese-American man who came over to do housework are trapped in the veteran's attic by a samurai sword that belonged to a Japanese soldier the veteran killed. The sword bears an inscription "the sword will avenge me". And it does, as it brings out the darker sides of both men, culminating in a violent struggle that ends with the veteran accidentally impaled on the sword and the younger man throwing himself out the window in a fit of suicidal guilt.
Dracorage in Forgotten Realms was murderous madness periodically magically induced in dragons world-wide. Designed by ancient elves to break dragons' control over the world, later magical device was hijacked and used by Sammaster to convince evil dragons that becoming Undead with his help is their only option to avoid insanity and then ignominious death.
Mindflayers are given magical stones that could potentially have this result in the D&D 3.5 supplement Lords of Madness.
There are two things that don't instinctively hate Prometheans — Vampires and Werewolves. Instead, they find Prometheans so unsettling that it actually becomes harder for them to resist their Unstoppable Rage — meaning that they'll quite likely end up killing the Promethean anyway, along with any other allies or innocents that are unfortunate enough to be there at the time.
One of the horrors described in the GURPS sourcebook Creatures of the Night is the Dread Blossom, a flower that makes people exposed to its scent paranoid and xenophobic.
Wraiths in Shadowrun can cause uncontrollable aggression in those near them.
Skarbrand in Warhammer and Warhammer 40,000 has a special rule which causes EVERYONE around him to reroll misses in close combat due to amplifies hate.
Some Apostates in Black Crusade can 'Inspire Wrath' in people against specific targets, with just a few words. It makes Player Characters more determined, and so more likely to, hit the subjects. NPCs are a little less predictable.
Classic Traveller Adventure 6 Leviathan. When the PC's explore the world Pa'an, the natives will use their psionic powers to inflict telepathically induced aggression toward other party members. The crew will begin by feeling antagonistic and short-tempered with each other, and within one to six hours will be actively engaged in trying to finish each other off.
Villains And Vigilantes adventure Devil's Domain. When the PC's are fighting at the Stonehenge tower, killing a demon will cause it to explode in a cloud of demon ichor, which becomes a toxic brown smoke. After the battle is over, if the PC's didn't destroy the smoke when it was created it will cause inhabitants of the nearby town to converge on Stonehenge in a killing frenzy directed at anyone who isn't infected.
In BIONICLE, the Dreaming Plague's first symptoms included irritability, which then grew to hatred and violent behaviour, finally leading to complete insanity followed by death.
This is one way Kurahk can use its power.
The entire Mega Man X series started because of Zero's body spreading a computer variant of this, causing robots to turn Maverick.
Although not necessarily a plague in it's own right, Mia Yung's blowpipe and poisoned darts can wreak havoc on unsuspecting enemies en masse in the video game Desperados- one tiny dart will send them into paranoid homicidal rage, opening fire on anything that is caught in their path, usually causing multiple deaths before the infected will either pass out or be gunned down by their former comrades.
Video game example (sort of): in Nethack, there is a "ring of conflict" that, when worn, makes every creature (including peaceful creatures and the player's own pets) start attacking the player and each other.
In Postal 2, when you complete all of your tasks on Friday, you suddenly get a newspaper highlighting how a Hate Plague has instantly affected the whole town. Now you have to make it back home amidst the chaos, which includes raining dervish cats. At least everyone's usually focused on killing each other instead of you in particular.
In Blood Omen: Legacy of Kain, the player can generate this effect with the 'Inspire Hate' spell, causing all nearby Mooks to ignore the player and attack each other. The description of the spell specifically states Kain's sadistic amusement with the effect this has on the survivors...
Kain gains the same ability in Defiance. In both cases it's related to the pillar of conflict.
This is the main goal of Dr. Regal in Mega Man Battle Network 5: Combine the Soul Net (unifying all hearts) with the power of the Dark Chip (makes people evil). We see a little bit of the effects during the cutscene before the Final Boss.
Gemini Spark's chapter's evil plan in Mega Man Star Force is to attach a virtual plus or minus to each person, invariably attaching the same sign to two friends, lovers, spouses, etc. so that they'd argue with each other. The game never explored the effect of two people with opposite signs...
It's pulled again at the end of the second game. The villain gets away with it for a while, too, and this time without the awkward positive/negative questions.
The Bonus Dungeon of the same game is a twisted Bad Future in which the villan's plan actually succeeded and humanity was completely wiped out. The result is a rather depressing dungeon where you wander around a world without life or hope, and kill insane versions of your allies from the normal time line and eventually confront a Bonus Boss who's sole intention is to escape to your world and wreak havoc on it as well.
The infectious "kombat rage" spreading from Dark Kahn'smere existence in Mortal Kombat vs. DC Universe is a straight example, though this is also subverted when Superman and Raiden eventually realize that they can focus their rage towards what they see as the invaders rather than each other. During gameplay, it also serves as a literally Unstoppable Rage.
In the video game Majesty: The Fantasy Kingdom Sim, one temple provides the spell "Rage of Krolm" which promptly fills your heroes with an unstoppable rage that gives them bonuses to fighting ability.
Used in spell form in Suikoden III, during the attack on Karaya Village, which results in Chris killing Hugo's friend Lulu, and Boris going berserk on unarmed civilians. Naturally, the bad guys did this to sour relations between the Grasslanders and the Zexens, so as to be able to conquer them both later on without any troubles.
Used in Command & Conquer 3: Kane's Wrath. The Brotherhood of Nod's Humongous Mecha the Redeemer can cause enemy units to go into a rage; attacking anything within sight (including their allies); but only after they finish off their current target first.
Black Hand Confessors in the same game can throw hallucinogenic grenades, which cause any infantry caught in their area of effect (including friendlies) to attack their own allies. Unfortunately, it doesn't affect vehicles.
Fallout 3 has Vault 108, a social experiment where the interior was pumped full of hallucinogenic gases to see how the inhabitants would react. Result: everyone had gone insane and killed each other.
Vault 92 as well. Using the internal PA system, everyone was subjected to low-frequency white noise with combat suggestions hidden in it. After a while, everyone who heard it gone berserk and brutally killed the nearest person.
Left 4 Dead doesn't actually feature the undead, but rather "infected" humans, in the vein of 28 Days Later, which the developers cite as an inspiration. Taking them further from the zombie stereotype is that they don't eat human flesh, or anything, for that matter, if a certain piece of safe room graffiti is to be believed.
Resident Evil 4 has this introduced instead of the zombie plague in all the other games in the form of Las Plagas, which (in their normal form) are only able to make their victims more aggressive, albeit controlled. Experiments show how much worse this can actually be for its victims.
In Trauma Team, almost all of the murders solved by Naomi was caused by the murderer being infected with the Rosalia virus.
Though it isn't straight up hate, but rather a result of frontal lobe tumors causing dementia. At least one murderer though she was trying to save her family from a Fate Worse than Death.
In BioShock, the Enrage plasmid causes splicers to go crazy (well, crazier than usual) and attack anyone— you, their fellow splicers, or even Big Daddies.
The sequel gives us a potential origin story for the Enrage plasmid and why the splicers in the first game are too angry to come up with any kind of plan against a juggernaut: the ADAM slugs love to eat a deep-sea plant that secretes red chemicals. This could be considered a passive-defensive mechanic, as anyone who consumes the chemicals from the flowers becomes really, really violent, and addicted to the stuff. You find one of Lamb's science staff, Gilbert Alexander, violently insane and addicted to the scent of the flowers in the area.
This happens in Pokémon Colosseum and its sequel Pokémon XD. Pokemon's hearts are closed, so that they have no sense of compassion, and only their primal bloodlust. They'll attack anything, and they sometimes go into uncontrollable rage fits.
Features in Deadly Premonition. A purple gas produced from the Red Seeds that drives people into a murderous rage was responsible for the Original Raincoat Killer incident.
And it happens again during the last mission of the game. Killing the Final Boss puts a stop to it though.
Kingdom of Loathing: Almost everything that increases monster leveling has a description to that effect. The Annoy-o-Tron, the badly tuned radio, the Canadian Mind Control Device which takes it Up to Eleven... even, as a Shout-Out to Nethack, a ring of conflict. Most infamous is the hockey stick of furious angry rage, which is imbued with everything that makes hockey hockey.
One of Omega's powers in Mega Man Zero is his ability to turn normally sane reploids into murderous psychopaths. This power combined with his bloodthirsty desire to kill is ultimately what caused the deaths of 90% of reploids and 60% of humans in the Elf Wars. Not surprising, considering it's the Maverick Virus from Mega Man X taken to its logical conclusion. Imagine a robotic Skarbrand and you have Omega in a nutshell.
The Spice from Sly 2: Band Of Thieves causes insanity and unbound hatred, the Big Bad Constaple Neyla/Clockla intends to use this worldwide hatred to fuel her immortality.
In the first Grand Theft Auto III, there's a cheat that makes all of the citizens attack each other. There's also a cheat that arms all of them. Use both cheats, find a good place to hide, and Pass the Popcorn.
In Twilight Heroes, some items that raise foe toughness have descriptions of this flavor. In some cases, your equipment makes you look like such a smug jackass that your opponents become stronger just from the desire to beat the smugness out of you.
In the latest World of Warcraft expansion, the Sha are creatures born of negative emotions that take possesion of their victims and make them living avatars of the power they represent, which include anger, doubt and hatred among others.
In Cave Story, Mimigas which eat a certain type of red flower instantly turn into gigantic, mindless killing machines. They did this in their past, on purpose, to prevent killer robots from annihilating them - and the Doctor plans to use this trait to turn them into an unstoppable army.
In Dead Space, this is the usual effect that Markers have on humans: they drive humans violently insane through hallucinations and induced paranoia. All the better to cause humans to slaughter each other and gain dead bodies which can then become Necromorphs. Certain smarter humans can resist the effects to some degree (with a very rare few completely immune to them), but the Markers can instead manipulate these individuals into performing other useful tasks for them.
The Infected of Dead Island react to the outbreak as such. Unlike the standard zombie Walkers or painfully self aware Suiciders they are locked in a permanent Berserker Rage a la 28 Days Later, intent to kill everyone and everything they possibly can.
Frenzy from The Daemonslayers. According to his Deviantartpage, the Dire Unicorn is constantly surrounded by a blood-red mist that makes any who breathe it overcome with violence and bloodlust that forces them to turn upon their fellows and tear each other apart. Those who survived and regained their senses often lost their minds anyway due to retaining the memories of what they saw and did under the effects of the rage. Despite his awful power, Frenzy is ironically one of the most peaceful of the dire unicorns and refuses to harm other mortals because he is still able to remember his name and former life as a noble unicorn, unlike his other brethren(such as Knightmare, who is currently the capricious mount to darkest Anti-Hero Blackjack) who were tortured into becoming evil perverse beings by the Demon Queen Shine. However, because Frenzy lives in a Crapsack World, he has absolutely no control over his powers and the effects of the curse that travels with him has caused him to slowly lose his mind and has now become quite insane. All this makes Frenzy (and every other decent person in the Daemonslayer universe, including even Blackjack) complete Woobies.
Played with to some extent in the "Barsoom Circus" story arc, involving elephant sophonts. Musth is rather akin to a mating period, wherein the affected species become extremely violent and territorial. The cause of this is generally unknown, though some hesitant efforts have been made to identify it. In Schlock, there are a set of elephants afflicted by something akin to it, but it's caused by nanites instead.
The "Random Access Memorabilia" storyline uses a nanite-based version of this, corrupting genetic engineering done to add variety to some members of over 950 million wormhole gate clones (It Makes Sense in Context) so that they get turned into Super Soldiers serving an underhanded faction of the UNS after being killed.
Spinnerette has something in the water at the Canadian headquarters....
On Atop the Fourth Wall, the Gunslinger trapped the cast in their apartment and set up a device that lowered their inhibitions and increased their anger; between the tension of the situation and pre-existing conflicts in the group, the situation shortly got violent.
The SCP Foundation has SCP-923, a Kill Sat which works by driving Ax-Crazy everyone at the targeted location. At it's most intense output level it permanently damages the fabric of reality, as if it were driving reality itself insane.
SCP-053 is an apparently ordinary three-year-old girl, except that anyone who is around her for more than a few minutes at a time becomes hyper-aggressive and homicidal. The one thing that didn't react at all to her was SCP-682, which is very confusing because it's otherwise an Omnicidal Maniac that tries to kill everything it sees. The Foundation tries not to think too hard about the implications...
Despite the name, it doesn't really fit. The infected often initially become violent, but will then begin to work together with other infected. In the second of the two-parter that introduced the plague, Cyclonus commands the other Decepticons to retreat after coming under fire from the Autobots, and they follow his orders unquestioningly. It's more of a "Lack of inhibitions" plague than a "hate" plague.
One example of the afflicted cooperating are the combiners. In spite of fighting amongst themselves minutes earlier, the Aerialbots re-combine into Superion. They later infect Defensor. Defensor immediately collapses into the 5 Protectobots; the five fight amongst themselves. The same happens when Galvatron raids the lab containing the plague. Menasor and Bruticus are touched immediately by afflicted Autobots and immediately collapse into 10 brawling Transformers.
The Decepticons' cooperation could be Fridge Brilliance at work, as hatred had already been a part of their driving motivation, so wouldn't necessarily alter their behavior as much as it does, the non-villainous characters'. Doubly so for Menasor and the Stunticons, whose bios indicate that they operate on a level that barely makes it up to Teeth-Clenched Teamwork.
In Justice League, supervillain Gorilla Grodd uses his mental abilities to give the team's minor issues with each other a little push, much to their embarrassment.
Both the first and secondCare Bears movies show the villains having a dark influence on surrounding people — the kids at the amusement park where Nicholas and the evil book are become rotten little monsters, and so do the kids at the camp where Dark Heart sets up shop.
One episode of the animated series featured a mysterious meteorite infecting a small town, making the surroundings dull and gray and the citizens depressed and apathetic. Then it started affecting the Care Bears and their Cousins, but fortunately they were able to Care Bear Stare the meteor into a deep hole on the outskirts of town.
The Thanksgiving episode involved an evil pie maker named Sour Sam, who bakes a bunch of "crabby apple pies," that causes anyone who eats them to act like grumpy jerks, and the only thing that snaps them all out of it is a young boy's speech about what Thanksgiving is all about.
The So Bad, It's GoodBatfink program featured main recurring villain Hugo A-Go-Go creating "hoke", a combination of hate and smoke. After it was released, the eponymous hero and his sidekick began arguing, including placing a lampshade on the overuse of the hero's "My wings of steel will protect me" catchphrase, with the henchman replying, "Yeah, yeah, why don't you get some new dialogue?"
An episode of Powerpuff Girls had Him replace everyone's love with hate, causing them to turn against the girls - even the narrator was affected.
Really hit home when the girls went to see the Professor. Imagine all the love a parent has for their children magically swapped with hate.
A more family friendly version is see in Theodore Tugboat, in the debut episode of Guysborough the Garbage barge. His grumpiness gets Theodore in a bad mood, which puts Emily & George in a bad mood and so on until the entire harbour becomes snappy with each other.
One episode of Dungeons & Dragons, featuring the usual "get to the one-chance exit back home" set-up, forced the kids to go through a maze to reach a portal. One part of the maze made all the kids become very aggressive, tetchy and downright bloodthirsty, which almost resulted in a nasty fight. Fortunately, Hank was able to snap everyone out of it.
The My Little Ponymovie had the Smooze, which, in addition to making everything putrid and covering the land in a thick layer of concrete-like substance, made characters touched by it aggressive, spiteful and pessimistic.
The little pink dog Courage once faced a literal sweeping Hate Plague called the "Cruelty Curtain". This energy barrier caused anyone it touched to become ridiculously rude to the point where benevolence was considered a crime. Courage managed to re-wire the Curtain so that it turned people nice—even its evil creator, who was later elected mayor.
The Smurfs: The Root Of Evil in the episode of the same name. The Yellow Hate Disease in "Hefty's Heart" would also count.
In SpongeBob's second christmas special, It's A SpongeBob Christmas, Plankton obtains a mineral called Jerktonium, and laced it on a loaf of fruitcake, so that whoever eats the cake become jerks. And so, everyone in Bikini Bottom (sans Squidward, he was already a jerk) eat the fruitcake and become jerks. The only exception was SpongeBob, eating the tainted cake doesn't affect him due to his tiny brain and pure heart.
In the Ninja Turtles episode "Splinter Come Home", Shredder secretly plants a device to increase a mutant's hostility to keep the Turtles from following him. When they eventually arrive where the device is planted, the Turtles' attitudes quickly degrade and they begin fighting each other until April is able to snap them back to their senses.
In an episode of the cartoon Toad Patrol, the toadlets enter a cave which is filled with red crystals and if one of the toadlets touched them, they became mean to anyone around them.
Alternate Reality Games
The Red Horse virus in the Year Zero ARG is a weaponised haemorrhagic virus that causes violent psychosis, encouraging the spread of a disease that would otherwise be self-limiting given its extreme virulence.
Mob mentality can often resemble this.
Historically, the Mob mentality revolving around Witch Trials seen in Salem, Massachusetts are said to have been amplified from ergot poisoning, caused by a bread mold found on rye bread with symptoms including mania and psychosis, making it a bit more literal.
In the right doses, the right drugs can induce a psychotic episode, which can lead to explosively violent outbursts. However, the victim is just as likely to pass out, have a heart attack, or go on a bad acid trip instead, so the effect can't be used reliably as a weapon.
Methamphetamine abuse and production. Methamphetamine abuse tends to lead to aggressiveness coupled with anger and paranoia (and in some instances can create a psychotic syndrome called amphetamine psychosis, which is almost indistinguishable from paranoid schizophrenia except that violence is far more likely in response to percieved threats, whereas most paranoid schizophrenics would want to run from or cower in fear before an imagined threat rather than fight it). When you add in the paranoia induced by the illegal status of meth use/abuse, this creates a volatile situation where people (especially users and cooks) are willing to hurt anyone who angers them/whom they see as a threat to their business or freedom. Breaking Bad is often an understatement of how horrifying "meth culture" can be.
Many illnesses, such as rabies or brain tumors, often result in mood swings and sometimes increased aggressiveness. Rabies is a real life Rage Plague, as it causes an aggressive, feral mentality in order to spread itself, through biting, and also causes the host to avoid basic survival instincts, in this case, drinking water, which leads to eventual death. Compare with the Rage Virus of 28 Days Later and the occasional side effects of G-23 Paxilon in Serenity.
Dogs (particularly English Springer and English Cocker Spaniels) can have something called "Rage Syndrome" which does resemble Hate Plague. Fortunately, it's rare and it only lasts a few minutes, and can, in most cases, be controlled with medication.
All Periods Are PMS, if a girl doesn't track her cycles and know when "that time" is about to come up again (or if she's just hitting puberty and hasn't settled into a predictable cycle yet). Of course, the culprit will become clear pretty soon, but, "My hormones make me crazy" isn't always bought as an excuse.