Top 20 Scariest Monsters in Anime

“Gantz” (2004)

In a posthumous game of cops and robbers with bloodthirsty aliens, encountering grizzly critters is an expected work hazard. But, this one flies well above the others, and not just because of its wings. They don’t call this humanoid bird monster the boss for nothing; compared to the other Tanaka aliens, he’s bigger, he’s badder, and he’s got a killer peck to prove it. But while he’s certainly an expert at taking his enemies for a lethal flight, he’s plenty menacing even before he spreads his wings. Thanks to an enhanced intellect, this thing is at the top of the food chain in more ways than one.

“Ranking of Kings” (2021-22)

This devil behind the scenes has a positively ‘killer’ track record in the wish-granting department, and is single handedly responsible for doling out some of the strongest abilities in the kingdom. Unfortunately, he also nevers fails to collect his debt, but that hasn’t stopped the simply-named “Demon” from tempting the likes of Miranjo and Bosse. Suffice it to say, it didn’t turn out very well for them. To be fair, he looked much more innocent in his youth, since he hadn’t granted enough wishes to completely turn into his monstrous form. Nowadays, though, the glowing yellow eyes and sinister smile are a literal sign that this genie is better left in his lamp.

“To Your Eternity” (2021-)

There’s few things as threatening as an adversary with no regard for their own safety. Enter: the Nokkers. Named so because they knock on the proverbial doors of paradise, granting them entry means they fight tooth, nail, and root to stop Fushi from saving the world. To do so, they become something of a new age “Invasion of the Body Snatchers,” completely overtaking anything they come into contact with – dead or alive. If the mindless stares weren't bad enough, they also take on the appearance of their environment.

“Dororo” (2019)

Don’t let her initial appearance fool you, this seemingly innocent woman is a spider-ghoul, and not a friendly one. This monster feasts on human flesh to sustain herself, but she’s no straight vampire. Instead, her true form is a scaly, terrifying blend of humanoid features and arachnid body parts that’s enough to send even the bravest warriors running for their lives. If the horrifying appearance doesn’t stun them, her sticky, threadlike appendages certainly will. And, then, it’s dinner time. She might take momentary mercy on Yajiro, but the same can’t be said for anyone else unlucky enough to get caught in her web.

“Blood-C” (2011)

They may not come out of a top hat, but they’ve certainly got a rabbit’s appetite. These ancient creatures follow their singular instinct to feed, and predictably, humans are their favorite dessert. When Saya tries to flip the table and slice and dice them into the first course, it only succeeds in helping them multiply, allowing them get their revenge by feasting a town’s population down to zero, finding increasingly perverse methods to spice up each dish of innocent life. Even worse, each Bunny comes with built-in moldable hands that make for the perfect silverware when going on a massacre.

“Black Bullet” (2014)

Evil parasites? Check. Enemy to all of mankind? Check. Gross disfigurations? Also, check. This is all pretty standard fare for terrifying anime monsters, but their undisputed track record makes them a clear apex predator. The Gastrea are basically unanimous winners in the fight for Earth, and succeed in reducing the human population by ninety percent. It helps that humanity ends up fighting itself, since the creatures’ bodily fluid turns them into more Gastrea. After a hard day’s work conquering the planet, the monsters are content to continue slithering, crawling, or stomping around in search of the remaining pockets of civilization. It’s clear this threat won’t be squased any time soon, especially since some Gastrea come in jumbo-size.

“Kabaneri of the Iron Fortress” (2016)

More of an infection than a curse, there’s no antidote or holy water that can save anyone bitten by one of these undead beasts. Once infected, their veins glow gold, their skin gets gray, and they get oh so rabid. The only saving grace is their distinct lack of intelligence or motor skills, but they heavily compensate for that through sheer numbers and a voracious appetite. Overland travel may have evolved leaps and bounds to compensate, but that’s hardly compensation when you’re looking down an oncoming tidal wave of Kabane!

“The Island of Giant Insects” (2019)

Even the worst 3D animation in the world can’t disguise how nauseating these things are. It’s hard to call these creatures nuanced in any way - they’re just overgrown insects native to a forgotten island, with a terrible habit of killing and draining the juices out of the unfortunate gaggle of adolescents who find themselves washed up on its shores. From butterflies to wasps to larvae, every one of these oversized bugs will make your stomach flip. Mother nature clearly made a mistake here, so will someone hurry up and flamethrower the whole place down, please?

“D. Gray Man” (2006-16)

The most chilling part of these adversaries are that they’re born from the one thing humans can never escape: grief. When a mortal calls upon a loved one’s departed soul, the Earl happily fulfills their wish - and then proceeds to trap it in the summoner's body. Powered by Dark Matter and a burning hatred for humanity, the Akuma live, if you could even call it that, to serve the Earl’s will and nothing more. Growing more powerful with each new kill, these souls were better off dead.

“Death Note” (2006-07)

They may use human souls to extend their lives, but that’s not the primary reason these Grim Reapers crack open the titular Note anymore. Instead, they take lives as a simple cure for boredom. Having lived so long they’ve forgotten what they’re true purpose is, the only enjoyment the Shinigami find anymore is meddling with human affairs. Their striking designs are each uniquely disturbing, but the cavalier attitude where the real menace comes from. After all, there’s nothing stopping them from scribbling the names of everyone left on Earth should the whim strike them. The only thing more terrifying than an all-powerful demon is one in desperate need of some entertainment.

“Claymore” (2007)

Lock the doors, hide the kids, it won’t matter since this monster could just as well be sharing your bed. The grayish true forms of the ravenously hungry Yoma are certainly worthy of a few screams of terror, but what’s even worse is they don’t need it to sniff out their victims. Instead, they stalk their prey by shape-shifting into them. An epidemic of flesh-eaters is bad enough, but when the paranoia of mimicry settles in, it’s clear why these Yoma have their due pickings on any village they want. The fact that only half-Yoma hybrids called Claymores can even hope to compete with them is reason enough to stay clear.

“Neon Genesis Evangelion” (1995-96)

It’s twenty-ish cherubic beasts versus the full strength of the government and a handful of EVA Units; how bad could the odds possibly be? Turns out, the answer is pretty dang bad. As expected, these holy invaders are far from angelic, evident by their appearance alone. The disturbingly experimental visual style, near-unbreakable force fields, and unique perspective on how to best wreck humanity, makes each and every Angel an absolute horror to contend with. When you find a way to make the EVA Units seem tame by comparison, you know you’re doing something right.

“Hunter x Hunter” (2011-14)

They say you are what you eat, but the insectoid Queen of this pest army takes the idiom a bit too literally. She transfers the attributes of her last meal to the next generation of eggs, which poses a problem to humanity when her diet consists of mortals and Nen-users. It ensures each new era of Chimera Ants are specifically crafted with fresh abilities to devastate Gon and the others with. Chief among their clan is Meruem, who dethroned the Queen, took down the Hunter Association President, and singlehandedly proved that the Chimera Ants can deliver more than just a few bug bites. Yeah, this King more than earned his crown.

“Parasyte -the maxim-” (2014-15)

As soon as these slimy infestites procure a host, they develop the instinct to devour others of that species, which feels like overkill on top of an alien invasion. It’s telling that their biggest weakness is their reliance on their mortal body, which is capable of falling to normal disease and wounds - if anything can even get close enough, that is. They blend into the crowd easily enough, but also come equipped with amazing reflexes, and the ability to make their appendages as rubbery as elastic, or as hard as steel. Basically, fighting them is kind of useless. Unless some of the Parasites have a change of heart like Miji, these guys are here to stay.

“Princess Mononoke” (1997)

In just the opening moments of this legendary “Studio Ghibli” film, they ‘spirited away’ any preconceptions that this was going to be a light-hearted journey. When the boar demon attacks the village, it’s wearing a coat of cursed worms that looks right out of a children’s nightmare. The fluid animation further highlights the deeply uncomfortable, spider-like movement, a feeling that only grows as they disperse to reveal the furry monstrosity beneath. Turns out the once benevolent boar was corrupted by and succumbed to the manifestation of his hatred, and it is not a pretty sight.

“Gyo: Tokyo Fish Attack” (2012)

Just when you thought it was safe to go back in the water, these sea creatures decided to vacation on land. Thanks to cybernetic enhancements from a failed wartime experiment, these sea-creatures are able to take a bite out of more than the usual fisherman and swimmer diet. There’s just something about a shark being able to chase someone up the stairs that adds an unprecedented sense of danger to creatures that had always had an easily exploitable weakness. Which is made all the worse when they start further mutating into all kinds of hybrid abominations.

“Knights of Sidonia” (2014-15)

How do you hope to compete with an alien that has shape-shifting skin defending a near-impenetrable core? The answer is, you don’t. Completely irrational beyond their instinct to destroy, the hostile Gauna won the war, for all intents and purposes, by wholly overwhelming Earth. Competing with their destructive capabilities in the final frontier is all the more tense given the fact they’ve already decimated humanity’s home once before. Ever-evolving, incredibly powerful, and notoriously hard to kill, these aliens aren’t just terrifying to humans, but the entire universe.

“Terra Formars” (2014-16)

Much like how humans hate cockroaches, these Martians have an unfortunate disposition to humanity. While these humanoid bugs haven’t been kicking around the cosmic calendar for as long as humans, their enhanced strength gives them an immediate advantage, not to mention their apex body that doesn’t feel pain or exhaustion. And, in true roach fashion, they have devastating numbers, meaning this infestation is here for the long haul.

“Attack on Titan” (2013-)

Boasting unreal size, strength, and menace, this race of giant monsters have left the remnants of humanity cowering behind walls for survival. They eat humans, regurgitate, eat some more, and continue the process with no signs of mercy, reason, or intelligence. They’re an utterly unparalleled threat to civilization, and that’s before even mentioning the terrifying variants like the Colossal, Armored, or Beast Titan. Decades of enduring their insatiable bloodlust begs the question, what’s worse? Getting killed by a Titan, or living in a world run by them?

“Berserk” (1997-98)

Even in an anime infamous for its cruel and unforgiving characters, nothing comes anywhere close to what these demon sovereigns unleash. As the masters of the apostles, the God Hand are responsible for some of the greatest cataclysms in human history, and there’s no indication they’ll change their wicked ways any time soon. Their most recent exploits in the series include tempting Griffith, sacrificing most of the Band of the Hawk, and setting into motion Gut’s bloody crusade for revenge. Anything that can take revelry in something as twisted as the Eclipse are the very epitome of revulsion and terror.