Main Characters | Hero Association (S-Class Heroes) | Villains and Monsters (Monster Association) | Others
Voiced by: Daisuke Namikawa (Japanese), Ray Chase (English), Christian Strempler (Latin American Spanish)
Debut: Chapter 7 (Webcomic & Manga), Episode 2 (Anime)
The founder of the House of Evolution who wanted to evolve humanity past its limits through forceful methods.
- Bait-and-Switch: His introduction almost set him up to be the Big Bad with a god complex and couldn't be reasoned with. However Saitama beating Carnage Kabuto abruptly shocked him into a HeelFace Turn and he abandoned all his thoughts of villainy.
- Break the Haughty: Saitama inadvertently does this by entering his "House of Evolution" and casually destroying Carnage Kabuto, whom he considers the proof of his belief in artificial evolution.
- Comical Overreacting: When he talks to Zombieman about Saitama, he says that the latter had paid a terrible price for his strength... he went bald. After a moment, he also adds in the part where Saitama is feeling complete disassociation from humanity and is progressively being distanced from his own, but the baldness came first.
- Cut Lex Luthor a Check: Sort of. After he's defeated, he devotes his genius to running a takoyaki stand using his genetically-engineered generating octopi. It's perhaps not the most practical thing he could do with his genius, but he seems to be happy.
- Evil Genius: It's even in the name itself.
- Evil Old Folks: He is over 70-years-old, but doesn't looks it thanks to having used a youth serum.
- Evilutionary Biologist: The entire gimmick of the House of Evolution.
- Expendable Clone: Played straight as well as inverted. He even considers himself expendable.
- Four Eyes, Zero Soul: Glasses? Check. Evil? More or less, though he more doesn't exactly like people.
- HeelFace Turn: Sort of. Having been psychologically beaten, he decides he's done with evolution and decides to open a takoyaki stand.
- Karma Houdini: Despite having unleashed Mosquito Girl (who killed a lot of people), sending his minions to attack Saitama, and creating Carnage Kabuto (who is implied to have killed plenty of people), he gets off scot-free short of the injuries he sustained at the hands of Carnage Kabuto. It helps that he decided to put being a supervillain behind him.
- Know When to Fold 'Em: After being defeated, he decides to devote his life to running an otherwise entirely-normal takoyaki stand, using regenerating octopi for meat.
- Identical Twin ID Tag: Unlike his lookalike clones, he parts his hair on the opposite side.
- Lack of Empathy: He has difficulty empathizing with people, paired with his drive to improve the human form through artificial evolution, he feels that the rest of humanity are practically lowly animals.
- Mad Scientist: Of course!
- Meaningful Name: Genus looks like "genius". It is also a biological term, suggesting his mad science specialty.
- Me's a Crowd: He created countless copies of himself. They are actually his employees and he doesn't seem to care much about them.
- Mistaken for Gay: A throwaway joke used when Saitama was told that the scientist had "a great interest" in his body... Of course, he is only interested in Saitama's strength.
- Nice Job Fixing It, Villain!: Created Zombieman who became one of the toughest superheroes around. He actually seems impressed and vaguely proud that Zombieman chose the hero life when they meet again. He still slightly annoyed that Zombieman wrecked his experiments when he escaped though despite having given up that life.
- Older Than They Look: That's not a young man in his late twenties you're looking at — it's a man who reached his seventies, upon which he discovered the secret to regaining his youth, and revitalized himself. As for his clones, it's the other way around, having been around for only a short amount of time but the same biologically as him in his youth.
- Omnidisciplinary Scientist: His backstory implies that he was an expert in several fields, though genetics became his specialty.
- Sherlock Scan: After seeing Saitama beat his ultimate monster, he correctly deduces that the man isn't just powerful, but that his power is without limits. This is proven true in Saitama's fight with Garou. Like Garou, Saitama gained more and more power each time he was heavily injured as Lord Gyoro-Gyoro's experiments proved. However, Garou and Lord Orochi eventually hit a limit they couldn't break while Saitama scattered that upper limit perhaps due to having an Enlightenment Superpower of a sorts.
- Social Darwinist: He believes humanity should use its expertise to accelerate their evolution to become stronger and smarter. When his ideas didn't get support, he resolved to build a utopia shaped by and for himself.
- Sole Survivor: After Saitama and Genos destroyed the House of Evolution and killed all of the members... Apart from some small fries. A picture in the artbook implies that Mosquito Girl may have survived as well (showing her fixed up with artificial limbs and working at his takoyaki stand), although whether it's canonical or not is unclear.
- They Called Me Mad!: In his youth, he called for humanity to find new ways to evolve. He didn't receive any mainstream support, and decided to go about it by himself.
- World's Smartest Man: Doctor Genus is implied to be this. His intellect was so advanced that he soon became disillusioned with the rest of humanity and could find no one else able to keep up with his level of thinking. He soon came to believe humanity was too far behind him and sought to help the human race evolve so that he would no longer be alone.
- You Are Number 6: While he wears dark clothing, his clones wear white jumpsuits and are differentiated by the number on their shirts.
Paradise GroupA terrorist group led by Hammerhead and consisting of unemployed young men, striving to create a utopia in which work is voluntary, and the unemployed receive full financial support.
- Bald of Evil: A defining trait of the Group is that every member has a clean shaved head. Saitama wasn't pleased when he heard about it.
- Curbstomp Battle: The whole Group was effortlessly slaughtered by Sonic and, while Hammerhead himself survived and even managed to put up a decent fight, he was still easily defeated.
- Empowered Badass Normal: They have no powers or abilities beyond that of a normal human, it all comes from their combat suits.
- Helmets Are Hardly Heroic: Admittedly, neither are they, but wearing helmets might have lead to less of them being decapitated by Sonic.
- Not-So-Well-Intentioned Extremist: Hammerhead and the rest of the group claim to be going about their destruction because they're rebelling against the corrupt elites of society, but in reality most of them (especially Hammerhead) simply don't want to have to work to get ahead in society.
- Off with His Head!: All of Hammerhead's henchmen by Sonic.
- Powered Armor: They use advanced combat suits to make up for their lack of powers.
Voiced by: Wataru Takagi (Japanese), Edward Bosco (English), Arturo Mercado Jr. (Latin American Spanish)
- Bald of Evil: He's not the nicest fellow around, and there's not a single hair on his head (nor on his whole body, as seen when Saitama destroys his armor, leaving him butt-naked).
- Born Lucky: He is born with a very, very thick skull, which saved his life when Sonic threw a kunai to the back of his head, and later when two agents of the Organization tried to kill him for stealing the battle suits in the first place.
- Brilliant, but Lazy: He managed to create a whole gang of devoted followers and outfit them with combat suits stolen from The Organization. His motivation for doing it? He just wants to remain unemployed and get paid for slacking off.
- Good Scars, Evil Scars: He has a large, horizontal scar across his nose.
- HeelFace Turn: After the events of Chapter 12/Episode 4, he gave up on terrorism and is actively looking for an honest job. Also, in Episode 11 is seen watching the events of the alien invasion on TV with his family, while filling in a job application.
- His Name Really Is "Barkeep": Hammerhead is indeed his actual name as it's what he uses to sign legal documents.
- Ineffectual Sympathetic Villain: Even Saitama seems to have a soft spot for him, and simply destroyed his armor and told him to run instead of gibbing him like most of the villains he usually deals with.
- In the Style of...: He looks like an Akira Toriyama character.
- Large and in Charge: He's over 7 feet tall, clearly towering over the rest of his henchmen.
- Large Ham: He's better at talking the talk than he is at walking the walk, that's for sure. It doesn't make him less of a threat, though.
- Not So Different: Saitama notes that like him, Hammerhead is a slacker by nature and wonders if he would have gone down a similar route.
- Powered Armor: Just like the rest of his Group, he wears an advanced battle suit to boost his physical strength to superhuman levels. The specific one he's wearing is an even more powerful variant, distinguished by unique flame decals emblazoned across its torso and thighs.
- Strawman Has a Point: Yes, having an job might not be as fun or exciting as it sounds. Yes, there are people starving out there because they're unemployed. But given the nature of the manga, this guy is preaching in an city where everyone is happy with their vocation and nobody is homeless.
- Strong Family Resemblance: He really wasn't kidding when he thanked his mother for his hard head: both his mother and grandmother share his unique skull-shape.
- The Big Guy: See Large and in Charge above.
- Unwitting Pawn: To the Organization, which let him steal their battle suits so he could test them in the field.
- Utopia Justifies the Means: Even if his "utopia" is just an excuse for lazy people like him to keep slacking off all day and still get paid for it.
- Well-Intentioned Extremist: Parodied. Hammerhead tries to invoke this trope, but it's hard to imagine a dumber, less practical goal.
"Hero Hunter" Garou
Voiced by: Hikaru Midorikawa (Japanese)
Debut: Chapter 45 (Webcomic), Chapter 39 (Manga)
"Hero Hunter" Garou; is a human, yet chose to side with the Monsters and actively seeks Heroes to fight and kill, or so he claims. Garou was formerly "Silverfang" Bang's pupil and his talent as a martial artist is tremendous, making him all the more dangerous as he doesn't rely on brute strength, but his fighting skill.
- Adaptational Attractiveness: his webcomic incarnation looks more like a thug; Murata drew him as an athletic handsome dude wearing tight-fitting clothing.
- Anti-Hero: Crosses the line between this and Anti-Villain, as it turns out he never really killed any heroes and doesn't even target civilians. Hell, he actually killed quite a few members of the Monster Association. He just wanted heroes to act more like the Ideal Heroes they should be.
- Arrogant Kung-Fu Guy: Used to be Bang's top student, before Bang found out Garou wanted to be a Monster. Garou is still quite confident of his skills, and pushes his limits daily. This backfires because Bang gets worried Garou might become an unstoppable monster, so he calls his brother, Bomb, for backup and they kick Garou's ass straight to the monster hospital. Yes, the monsters have a infirmary for monsters that get beat up by heroes and survive.
- As Long as There is Evil: Played with — Ultimately, Garou wants to be the "world destroying evil" simply because at least against him humanity would stand a chance, because they could stand up against him as many times as it took to beat him. And by focusing on him, humanity would never have to worry about its greatest enemy: Itself.
- Awesomeness by Analysis: Garou is not only very skilled at fighting, he's also able to figure out the weaknesses of his opponent's fighting style through simple observation alone. Opponents may get some hits in at first, but once Garou figures out the technique, he will be able to counter anything that the opponent uses. He also does research on his targets to be able to better prepare himself for their inevitable meeting.
- Berserk Button: Absolutely DO NOT be a condescending jerk about Justice and Heroism in Garou's presence unless you want the most humiliating beatdown of your life, which Sweet Mask learned the hard way when he tried to give a lecture on how pathetic the S-Ranks were being mid-battle. Garou responds by literally punching his face in, mid-rant.
- Big Eater: In Chapter 134, Garou ordered all the meats and salads on the menu at a restaurant and was able to eat the entire serving before attempting a dine and dash. Granted, before that the guy was unable to get a decent meal for at least over a day.
- Big Bad: The first true over-arching villain the series has ever had, and genuinely retained this for a time.
- Big Red Devil: His unusual being appearance plays with it. His horns used to be his hair before he gained the desire to become a real monster for heroes to fight. This does two things: it changed his physical appearance to one similar to a demon, and all his hair turns into his two "horns", leaving him bald.
- Butt-Monkey: When Garou starts his crusade against heroes in the manga, he's just as likely to get his ass kicked as he is to kick ass. Against Watchdog Man for instance, he gets utterly outclassed and has to retreat, only escaping worse punishment because Watchdog Man doesn't venture outside his own territory. And every time Garou runs into Saitama, he gets knocked out instantly, with Saitama never even realizing who he punched out. One time Saitama even wonders right afterwards about that Hero Killer he had heard about and whether he'd possibly be a challenge seconds after punching Garou through a wall. Overall, Garou has been knocked out thrice by Saitama before their ultimate confrontation.
- Card-Carrying Villain: He has "Hero Killer" as a title. He introduces himself by walking into a meeting at the Hero Association, which is full of various rogues and evil doers. (in-context: The association was putting the word out about the world-ending prediction, hoping the Underworld might decide the world ending is against their own self-interests), and loudly proclaiming they are all weaklings and that he, the Human Monster, could defeat all of them right here to prove it... and then he actually does it. He then goes for a casual stroll while making a threat to the Hero Association head. He also doesn't pay for his meals.
- Came Back Strong: One of his abilities seems to imply "What doesn't kill me, only makes me stronger". And he's become very, very strong indeed.
- Chekhov's Gunman: He is mentioned in passing as the student who Bang beat up and expelled due to going wild and beating up all of the other students in Bang's dojo. He shows up several chapters later as a villain.
- Clipped-Wing Angel: When all of his areas of expertise are trumped by just how horribly unfair Saitama's strength is, Garou gradually becomes more and more of a literal monster. However, all this does is make him bulkier and easier to hit, though this makes him durable enough tank Saitamas normal punches.
- Curb-Stomp Battle: Both played seriously and played for laughs — played seriously in that Garou is really brutal in beating up heroes, then played for laughs when Saitama lightly taps him for Dine-and-Dashing, which results in a OHKO. Ditto when Saitama mistakes him for a mugger while he's out wig shopping.
- His ultimate fight with Saitama is inevitably this. Even after evolving over 4 times into his "unfair evil" ultimate mode, he's unable to hurt Saitama. Despite this, it is one of the few fights that subverts the titular One-Hit KO rule, even getting Saitama to pull out his "Serious Series" moves to incapacitate him.
- Deliberate Injury Gambit: Several times Garou takes advantage of his Healing Factor to tank an attack in such a way it allows him to get in close and punish his opponent several times over what he got, such as when he impales his hand on Spring Mustachio's Finishing Move in order to take him out with one good strike.
- Deconstructed Character Archetype: Of Balance Between Good and Evil and As Long as There is Evil. Garou represents the idea that as long as good and evil both exist in the world, there needs to be a "balance" between them. As long as evil exists in the world, there needs to be good as well, and the only way that an absolute good can exist is for an absolute evil to simultaneously exist. Garou (and most people) assume this means that the "good" have to be good, kind people and that the "evil" have to be evil, despicable people. The deconstruction comes into play when it's revealed that Garou isn't really evil. He has a body count of zero, causes no civilian fatalities and actively avoids harming innocent people, such as when he relented from his assault on Metal Bat at Zenko's request. Garou doesn't even want to be evil, but he feels he has to in order to create an absolute good to beat him and protect the world. Saitama slowly challenges his worldview by bringing up the fact that he's a good person who basically went with a half-hearted monster hobby because he lacked the conviction to follow the hero hobby he really wanted, and in the end defeats him by asking him if he's okay with being a villain- Garou's facial expression very clearly says he isn't.
- Determinator: Even beaten, tired, wounded and poisoned, he never gives up and stops fighting.
- It's also deconstructed because he isn't enough of a determinator. Despite never stopping in fighting, he became a monster as a compromise. His real goal was to be a hero, but he lacked the conviction to follow through and according to Saitama, it's because he lacks confidence.
- Even Evil Has Standards:
- Isn't interested in killing civilians like "some sort of crazed mass murderer" — He's only a Monster to fight Heroes — and still takes time to help some fat kid with his bully problems who is later kidnapped to lure out said Heroes by the monsters, repeatedly, but the latter times were mostly to save the kid's life from Garou's monster allies who would have killed the child. Then Garou kidnaps the child back from the other monsters, just so a hero is guaranteed to come after him.
- He seems to subvert this when, after beating every S-Class hero who came to stop him, he threatened to kill the child, but this turned out to be a bluff, as Saitama pointed out he was walking away from him.
- Evil Is Easy: According to Saitama, this is why he actually became a Noble Demon. To Garou, it was alot easier trying to bring world peace by being an all-powerful evil monster, because all he had to do was beat heroes. As Saitama observed, Garou chose this route because he did not have the confidence in himself to actually be a hero. It's also deconstructed, since he deep down doesn't wanna be a monster and so no matter how strong he gets, his half-hearted conviction means he will never win and he's miserable throughout it all. Evil may be easy, but that doesn't mean you'll end up achieving what you really want.
- Expository Hairstyle Change: The aftermath of his battle against Saitama left him with shorter hair, as if to symbolize his previous horns-like hairstyle, which morphed into actual horns, was a reminder of his desire for enacting evil to maintain balance with good; his later appearances shows Garou kept his short hairstyle.
- The Faceless: As Demi Garou — although you see a few features, eventually he gets so strong due to Saitama getting serious on him, almost everything about him is blacked out and featureless - you can't even tell WHAT he looks like anymore. And then Saitama literally punches his face and scalp off revealing his human eyes.
- Flash Step: Most notably when giving his "Reason You Suck" Speech to the contingent of S-Class heroes, he frequently starts a sentence in front of one hero, and finishes it in front of another, with the heroes still looking at his old location, the implication being that he flash-stepped so fast that nobody could follow him. He also manages to close the distance between himself and many of the heroes, hit them, and then move back fast enough that it appears that the hero was hit by thin air. Happens to Sweet Mask, Child Emperor and Zombieman. He also flash-steps multiple times during his other fights.
- Foil: To Saitama. Both of them have a strong sense of morality and justice, albeit manifested in different ways. While Saitama wanted to be like a hero from his childhood who fought villains, Garou wants to be a monster who defeats heroes. While Garou is a genius fighter and a prodigious martial artist, Saitama is an ordinary person with no fighting technique. Furthermore, Garou can enjoy the feeling of losing in order to improve himself to become stronger in most of his fights, while Saitama desires to have a worthy opponent to find the rush of excitement he once had while he was training.
- From Nobody to Nightmare: Began as a somewhat eccentric kid who thought Evil Is Cool. Became one of the strongest villains in the world, and proud of it.Except maybe not so proud about it.
- Good All Along: Saitama certainly thinks so. Judging by Garou's expression when Saitama explains it, he's right. He (and the other Monsters) also note that Garou went out of his way to avoid actually killing any humans during his so-called Hero Hunt. He also reveals that Garou's threat to kill the child he spent his entire story arc protecting was a bluff by pointing that Garou was walking in the wrong direction. Saitama quickly grows bored of their fight for this very reason: Saitama became a Hero because he wanted to fight villains. Garou isn't a true villain — he's just a guy making a ruckus in Saitama's neighborhood.
- Good Thing You Can Heal: Another of his abilities: the ability to adapt his body and slowly heal himself. His body is physically battered by the end of his arc, but the man has sustained such a massive beating that it's a wonder he's even standing.
- After a few more evolutions later on, he could even regrow limbs in seconds.
- Healing Factor: Gets his ribcage broken in his fight with Super Alloy Darkshine. It heals in minutes.
- Hero Killer: Oh come on, it's in his villain nickname. Near the end of his arc, he beats nearly every single hero that was S-Class, including a partially weakened Tornado, and even the A-Class number 1 without any effort. Though Saitama notes that Garou didn't actually kill any of them.
- Horned Hairdo: His hair is styled in Mishima-style horns. And as he gets stronger and stronger it gets wilder and pointier.
- I'm a Humanitarian: Chows down on the meat of some monsters he slaughters at one point, stating that "food's food" and he needs to restore energy. Note that many monsters were originally human.
- Hyperactive Metabolism: In chapter 134 he recovers from a beating by going to a diner and ordering all of their meat dishes (for protein and calories) and salads (for the vitamins) and washes it down with plenty of water. Right after he finishes his meal, his injuries immediately start to vanish as his Healing Factor kicks in.
- Irony: Yells at Saitama not to underestimate him. Proceeds to underestimate Saitama. He gets reduced to a Butt-Monkey.
- Knight of Cerebus: Ultimately, this is the sort of Monster Garou wants to become — the type of monster that, once it appears, changes the atmosphere of a battle completely. He becomes capable of defeating almost all the S-Rank heroes and he actually makes Saitama fight seriously-ish, but in the end he never manages to get Saitama to consider him a monster.
- Large Ham: He's loud and bombastic, like the cartoonishly hammy supervillains he worships.
- Lightning Bruiser: Second only to Saitama in terms of strength, speed and durability. Word of God implies he's approximately as powerful as Boros.
- Mad Eye: As he takes more and more damage and evolves further, his right eye begins to change a darker color.
- Meaningful Name: Of the ironic type. The dreaded Hero Killer is named after a wolf, the lowest threat level classification for a monster, which only signifies a potential threat to a group of people. Turns out more accurate than not by the end of Saitama's fight with him though.
- Meaningless Villain Victory: Played with. In the case of the Hero Association officer Muffintop, Garou likened the sense of clobbering him to stepping in crap knowing full well said pencil pushing reprobate was lying douche bag looking to cop a feel off of those girls.
- Mook Horror Show: Probably the best example, since he managed to last an entire fight against Saitama. Not only he is a category above the entire S-Class heroes, but his abilities went to the point that he could block literal light-speed punches, and cuts that could split atoms, by evolving god-like abilities in martial arts. Then Saitama, an amateur with "normal punches", crushed him over and over again, to the point that he crossed all the possible ways to defeat him. Due to this, Garou labels him the representation of the unfairness of justice. Even becoming the unfairness of evil left him only as a punching bag for a couple of minutes.
- Mr. Fanservice: Garou has many shirtless scenes, showing off his muscular torso, shoulders, and chiselled abs. Word of God claims that Garou's back is a reference to Bruce Lee's muscular back.
- Nightmare Fetishist: Ever since he was a kid, he would always play the role of the monster that the heroes fight. Always. Of course he respected the monsters due to their more often than not superior effort. Unfortunately, certain kids took advantage of this to have an excuse to beat him up. This just made him more determined to become the sort of monster that can beat self-centered, self proclaimed "heroes" like them. Ironically, if it was the other way around, he would've been a lot like Genos. And it later turns out he never really went evil, either.
- Noble Demon: He definitely shows a degree of martial honor and is upset by crueler tactics or sleazy individuals, though he claims otherwise. Saitama realizes, if anything, the Demon part is the one that's suspect. A certain manipulative Skirt Chasing HA administrator who milks the company budget to pick up chicks found this out the hard way.
- Nonchalant Dodge: It's repeatedly noted in his manga incarnation that he dodges attacks and projectiles with a minimum amount of movement. Yet, the trope is subverted because Garou does take the dodging seriously as his human body is still vulnerable to blows and projectiles. It's just that for a martial artist of his level, it's the most efficient way of evading damage.
- Oh, Crap!: Breaks instantly out in cold sweat in the manga when he first meets Saitama who no sells Garou's sneak attack with the highly sophisticated method of not reacting to it at all. Garou forgot about this encounter afterwards.
- Has a series of this during his fateful confrontation with Saitama. Whenever Garou thinks he has cornered Saitama, he is proven wrong. Becomes the cause of his Villainous Breakdown.
- Older Hero vs. Younger Villain: He is the "younger villain" being 18-years-old, while Saitama is the "older hero" being 25-years-old.
- One-Winged Angel: Played straight when he becomes a bald, horned figure to mirror Saitama's own generally basic appearance. Then inverted when he starts trying to milk it further.
- Pet the Dog: When Metal Bat's little sister throws herself in between the two of them, Garou actually follows her request to stand down, claiming he's too busy to keep wasting time on Metal Bat. And when a Monster Association goon considers grabbing Zenko as a hostage, Garou kills him, supposedly because he didn't like being watched.
- Poke the Poodle: He doesn't pay for his meals. And ultimately, his entire "villainous" career-compared to monsters in general, the property damage he does (accidentally) and repeated nonlethal humiliation of heroes is barely worth mentioning.
- Power Makes Your Hair Grow: His hair grows outwards wildly, and becomes more horn-ish as he fights and becomes stronger until he transforms into a mysterious being and his hair becomes real horns. He goes bald in exchange, though.
- Pummel Duel: Manages to endure Saitama's two-handed Consecutive Punch Combo for awhile. The is quite an achievement, considering what normally happens when Saitama uses the one-handed version.
- Rapid-Fire Fisticuffs: One of his moves.
- "Reason You Suck" Speech: Ends up getting a form of one from Saitama once Garou learns of Saitama's reasons for heroism. It sums his true colors and Garou's faults:Saitama: Really, Garou. So you did have an "image of an ideal hero" in you all along. I see now. I now understand what you wanted to do. Even though you said you wanted to be a "Monster of Absolute Evil"... What you really wanted to be was a hero. You compromised and decided to be a monster. To bring about world peace, you took the easy route, thinking a monster's job was quicker and easier's than a hero's. A monster's role is simple after all, all you had to do was defeat heroes. It's perfect for someone with no confidence like you. But you can never defeat me. Peace made by ruling the world with fear can't succeed as long as you can't defeat me. It will never work. It's absolutely impossible for you. Your compromised monster hobby! Versus my serious hero hobby! Even if that's all I had, I still wouldn't lose! It was a mistake to lower the hurdle right before the goal. A half-assed objective can't succeed.
- Reused Character Design: Give him a few guns and make him wear football gear, he'll look like Yoichi Hiruma from Murata's previous work Eyeshield21.
- Scarf Of Asskicking: As he progressively gets stronger, he eventually gets an ominous scarf.
- Shadow Archetype: To Saitama, but not for the reasons you might think. While Saitama grew up wanting to be a hero and Garou grew wanting to be a villain Garou made a mistake. Garou always liked villain designs in his cartoon show as a kid, but he didn't empathize with the villains because they were evil. He adored their personalities and designs over the show's Boring Invincible Hero. He convinced himself that he rather be a monster and that he hated heroes, but what he hated was heroes that weren't ideal or who were just plain bland. When it came to Tarou, he just couldn't stand seeing the kid get hurt like he was as a kid and defended him with his life. With the heroes, he just wanted to upstage them and knock them down a peg, not kill them. He didn't have the same qualms about killing monsters especially when they tried to hurt innocent people, especially kids. In the end, while he gained power in the same way Orochi and Saitama did, he couldn't break the final limiter because he wasn't enlightened like Saitama is.
- Super Speed: Fast enough to outspeed Lightspeed Flash.
- Super Toughness: Durable enough to survive several punches coming from Saitama and able to walk away from it relatively unharmed.
- Taking a Level in Badass: During the entire Monster Association Arc we see Garou taking several levels. From a guy that had difficulty in defeating an A-Class hero, to one that can defeat several. At the last part of the arc, he curbstomps several S-Class heroes and gives Saitama a slightly tough fight.
- Talking the Monster to Death: It's very gradual, but Garou's worldview is very slowly deconstructed. Saitama breaks it by asking simple questions during the fight (it didn't hurt that Garou's previous responses stopped working), and even after he's beaten ("Are you Okay with that?") Garou seemingly decides to stop being a villain after seeing the kid that constantly got kidnapped throughout the arc stick up for him, simply because Garou saved his life every time, and retreats.
- Teens Are Monsters: He is an 18-year-old teenager who sometimes refers to himself as the "human monster".
- A Twinkle in the Sky: Eventually Saitama uppercuts him so hard he flies into orbit... AND THAT STILL DOESN'T KILL HIM. This just makes him disappointed that Saitama's strength is unfair, so he just resolves to become a "unfair Evil" in order to stand against him and he returns in a bigger form.
- Villainous Breakdown: He starts losing it the longer he fights with Saitama and seeing how outclassed he is.
- Walking Spoiler: His true motivations and the truth about his actions are major spoilers.
- Weak, but Skilled: For extremely relative values of "weak", but Garou is noted as posing a particular threat because, while previous monsters relied on brute strength to overwhelm heroes, Garou fights with actual martial arts and specializes in redirecting his opponents' attacks instead of just countering them. Basically, his fighting style is geared specifically towards defeating heroes. Once he goes One-Winged Angel, he becomes this especially in comparison to Saitama, as while he's still much weaker (something he himself admits), he completely surpasses him in terms of martial arts and even manages to force him to fight "Semi-Seriously".
- Well-Intentioned Extremist: For all of his posturing, this is what he really is-by forcing the world to unite against his "evil", he's unifying it. That, and he really isn't a cruel person at all.
- What Measure Is a Non-Human?: Played with — Garou has a interesting mindset on what a monster should and shouldn't do, and other monsters question if he's either too human or an outright scary, wild force of nature.
- Wild Card: Garou doesn't have any qualms about massacring weak "villains" or monsters that disappoint him. He also has a weird habit of letting the Heroes he savagely beats up live, simply so they can get stronger for the eventual rematch.
- The Worf Barrage: In the end, his self-evolution-adaptability powers. Each hit of Saitama literally made him stronger and stronger until he became a demonic god-like being... and then it simply couldn't go higher, and ended up regressing him with each subsequent punch ultimately reverting him to his human form. Saitama literally killed his ultimate villain concept of Came Back Strong, one attack at the time It's implied it's because deep down, he actually doesn't want to be a monster.
- Would Hurt a Child: Garou has no hang-ups about punching Child Emperor hard enough to send him flying through the air. He also taunts the defeated S-Class heroes by threatening to kill the boy who has been used as a hostage throughout the story arc. Saitama calls his bluff, pointing out that Garou was walking away from the boy instead of towards him (Saitama was the only person whose night vision was good enough to see this).
- You Are What You Hate: After finishing his desperate Motive Rant, he becomes outraged that Saitama isn't acting as a proper hero... which means that for all his hatred of heroes, he did have a concept of an ideal hero after all, and his actions, at their core, were born from a desire to make the world a better place, as described below.
- Younger Than They Look: Garou looks like he is in his mid-20s, however Chapter 134 reveals that he is only 18-years-old.
- Zero-Approval Gambit: Revealed to be his true modus operandi: he believes that only a grand, unifying evil can force heroes to truly act like ideal heroes, and force everyone else to set aside their own differences. Saitama calls him out on this as since not even Garou seems to really approve for it; his gambit was the result of compromise and thus lacks full conviction.
Mysterious BeingsMysterious Beings are monsters that attack and terrorize cities and the main antagonists of the series. The series' setting has a lot of monsters, mostly due to a currently unknown factor (although some beings have an explained background). Normally these monsters would be quite dangerous, but in One Punch Man these creatures usually exist simply to be reduced to a fine red mist in a single panel the moment our hero, Saitama, shows up. There are some subversions to this, like monsters that are fought by other heroes being shown to be quite strong, and the monsters are slowly getting tougher. It is later revealed that they even have their own secret society, so expect longer articles the further into the series we go.
Voiced by: Yasutoshi Tokumoto (Japanese), Tom Fahn (English), Alan Prieto (Latin American Spanish)
Debut: Chapter 2 (Webcomic and Manga), Episode 1 (Anime)
Disaster Level: Tiger
The very first monster that ever appeared in series. He was Saitama's first kill.
- Alien Blood: His blood seems to be yellow along with the rest of his organs as shown when Saitama rips his eye out. Ironically though, crab blood is translucent blue in real life.
- Attack Its Weak Point: The carapace may be tough, but those eyes on stalks are convenient weak spots.
- Disproportionate Retribution: The big-chinned child drew nipples on his shell with a magic marker. His reaction is trying to hunt down and kill the kid. The same thing happens to anyone who even off-handedly comments on his appearance.
- Evil Is Petty: Primarily attacks people who make fun of his appearance or otherwise inconvenience him, no matter how slightly.
- Eye Scream: Saitama tears off his eyestalk... and the entirety of his insides with it.
- Giant Enemy Crab: A gigantic humanoid crustacean and Saitama's first real foe.
- Ludicrous Gibs: After Saitama tears off his eye, all the crab meat inside starts rocketing out like a firehose, covering the area.
- Signature Laugh: "Buuu-ku-ku-ku-ku!"
- Starter Villain: The very first monster Saitama fights, in-universe, before his training — and the one who causes him to start training in the first place.
- Stock Underwear: Sports a pair of tighty-whiteys on his human lower half, making him look quite silly.
- Super Hero Origin: Parodied, Crablante turned into what he is simply by eating too much crab food.
- Super Strength: He is powerful enough to shatter the earth with his claws.
- Tattoo Sharpie: Crablante had nipples drawn on him by a kid using a permanent marker. Crablante notes that the marker could be scrubbed off, but as he has two giant crab pincers for arms, he can't possibly clean it off himself.
Voiced by: Ryusei Nakao (Japanese), Christopher Sabat (English), Marcos Patiño (Latin American Spanish)
Debut: Chapter 1 (Webcomic and Manga), Episode 1 (Anime)
Disaster Level: Dragon
A being formed from mankind's pollution which seeks to wipe out humanity for the sake of Mother Nature.
- Alien Blood: His blood is dark green
- Barbie Doll Anatomy: Completely naked but possesses no attributes.
- Captain Ersatz:
- Gaia's Vengeance: He considers himself to be an incarnation of nature's wrath, sent to wipe out humanity, which he thinks is an infection, as well as a vaccine to protect Earth against future infections. This is parodied overall; many old-school Japanese hero shows have similar villains, almost all of which are designed to teach the viewers and/or the characters a Green Aesop. However, Vaccine Man is immediately OHKO-ed by Saitama upon his introduction, and nobody learns anything from him.
- Having a Blast: His power is to create energy balls that can explode entire city blocks.
- Kill All Humans: His solution to save the planet.
- Killed Mid-Sentence: Twenty words isn't nearly enough to tell a non-half-assed backstory adequately before Saitama gets bored.
- Large Ham: Before he's killed by Saitama, he makes a big entrance and declares his Evil Plan in a grand and showy manner.
- Ludicrous Gibs: His final fate is having his guts splattered all over the city he just destroyed.
- One-Winged Angel: He starts bulking up to a monstrous degree in order to fight Saitama. Not that it helps.
- Person of Mass Destruction: Destroys a city in his first appearance.
- Size Shifter: Is able to increase the size of his body.
- Starter Villain: He's the first monster shown to be fought by Saitama and simply exists to show how overpowered he is. Unusually for the trope, he is one of the more powerful villains of the series.
- We Hardly Knew Ye: Dies within a few panels of being introduced in order to show the premise of the series.
- Would Hurt a Child: He was about to kill a young girl before Saitama got to him.
- You Have Got to Be Kidding Me!: Doubles as Lampshade Hanging.Vaccine Man: You're a fast one. Who are you?
Saitama: Just a guy who's a hero for fun.
Vaccine Man: FOR FUN?! You're kidding. What kind of half-assed backstory is that?! Mine is far superior!
Oldface & Beefcake
Voiced by: Takuma Suzuki (Oldface) and Shinya Hamzoe (Beefcake) (Japanese), Kirk Thornton (Oldface) and Bryce Papenbrook (Beefcake)(English), Miguel Angel Leal (Oldface) and Adrián Fogarty (Beefcake) (Latin American Spanish)
Debut: Chapter 1 (Webcomic and Manga), Episode 1 (Anime)
Disaster Level: Dragon
A scientist and his brother, who mutated into an absolutely colossal giant.
- Astonishingly Appropriate Appearance: Coupled with Meaningful Name: Oldface has a prematurely wrinkled face, and Beefcake is a musclehead.
- Attack of the 50-Foot Whatever: Beefcake gains a truly terrifying size. Skyscrapers only go up to his ankle.
- Barbie Doll Anatomy: Averted. Saitama demands Beefcake put on some pants, though nothing is shown to the audience thanks to literal clouds being used as Censor Steam.
- Big Guy, Little Guy: Before and especially after Beefcake's transformation.
- Big Little Brother: Beefcake was already the bigger of the two pre-transformation. Needless to say he is afterwards.
- Black Comedy: Oldface tells his brother to kill the guy on his shoulder. Beefcake does as he is told... but goes for the wrong shoulder, the one his brother is on, causing his brother to get reduced to bloody mush to the despair of Beefcake.
- Brains and Brawn: Literally the name of their team.
- Captain Ersatz: Beefcake is one to the Colossal Titan. The English dub even has him voiced by Eren Jaeger's voice actor.
- Drunk with Power: Both Oldface and Beefcake relish in the destruction they are now capable of. Oldface cackles psychotically at the thought of thousands dying at Beefcake's hand, while Beefcake is overjoyed at finally achieving his dream of being the strongest in the world, or so he thought.
- Dumb Muscle: Beefcake accidentally kills his own brother just because he tried to smash Saitama... who was on his other shoulder.
- Exact Words: Oldface, while on Beefcake's right shoulder, commands Beefcake to kill Saitama who is on his left shoulder. However Oldface ordered him to "kill the man on your shoulder!" So Beefcake kills him by accidentally slapping the wrong shoulder.
- Little Big Brother: Beefcake was the larger of the two before he even drank the serum. And after his transformation... well it goes without saying.
- Mad Scientist: Oldface makes a Super Serum that turned his brother into a stupid and super strong giant, so they cause destruction.
- Magic Pants: Averted. Beefcake's transformation destroyed all his clothes, pants included, Instead Censor Steam is used to cover his private parts.
- Not So Different: Saitama understood exactly how Beefcake felt, being the strongest in the world feels utterly meaningless.
- Person of Mass Destruction: Beefcake. He can sweep multiple city blocks clean with a literal wave of his hand.
- Roaring Rampage of Revenge: Beefcake goes on one after accidentally killing Oldface and blaming it on Saitama.
- Sibling Team: The Brain and Brawn brothers.
- Super Serum: Oldface makes one that turns Beefcake into an immensely giant man.
- Sympathy for the Devil: When Beefcake accidentally kills his brother and sees his strength as a curse, Saitama says he knows how he felt... before killing Beefcake with one punch.
- Unskilled, but Strong: Beefcake relies solely on his brute strength and has no technique to his fighting, much like Saitama.
Voiced by: Christopher Corey Smith (English)
Debut: Chapter 33 (Webcomic), Chapter 30 (Manga), Episode 10 (Anime)
Disaster Level: Unknown
The ruler of the skies, seeking to take over the world with his minions, the Skyfolk.
- Bird People: His race are winged humanoids with bird-like traits.
- Breath Weapon: He and his Skyfolk can fire energy blasts from their mouths.
- Tengu: The Sky King and his minions resemble Tengu.
- Underestimating Badassery: He believed that he can take down the Hero Association's main headquarters. However, he did not even get the chance to be proven wrong...
- We Hardly Knew Ye: Him and the Skyfolk are unceremoniously killed by Melzargard just as their invasion began.
Voiced by: Ariumi Naito (Japanese), Tara Sands (English), Marisol Romero (Latin American Spanish)
Debut: Chapter 20 (Manga), Episode 6 (Anime)
Disaster Level: Tiger
A seaweed monster roaming about Z-City.
- Ambiguous Gender: On The Other Wiki, they aren't referred as a he or a she and have a very androgynous appearance and voice, assuming gender can be applied to them at all.
- Affably Evil: Is rather chirpy and bordering on Friendly Enemy-levels of attitude, even in combat. They even regard Spring Moustache as a Worthy Opponent.
- Alas, Poor Villain: In the manga at least, we get a shot of them weeping woefully on the ground after Saitama ripped off all of their kombu and used it for soup stock. Though considering what Saitama does to most monsters that incur his wrath, they got off pretty easy.
- Killer Rabbit: You wouldn't expect a seaweed-hair monster to be a threat capable of hospitalizing two high-ranking A-Class heroes without difficulty, but it is and it does.
- Irony: He came to Saitama's neighborhood looking for a legendary monster rumored to live there. No guesses needed to figure out who the "monster" is.
- Not Quite Dead: The manga reveals that Saitama tore off their kombu without actually killing them.
- Offscreen Moment of Awesome: We don't get to see how Saitama deals with it. But it involved breaking a building in two.
- Prehensile Hair: Well, technically it's not hair but it sure fills this role.
- Worthy Opponent: Considering that they are in awe after Spring Moustache defends against their attacks with little difficulty, it's easy to tell they view him as this.
Deep Sea King
Voiced by: Rikiya Koyama (Japanese), Keith Silverstein (English), Carlos del Campo (Latin American Spanish)
Debut: Chapter 24 (Webcomic), Chapter 23 (Manga), Episode 7 (Anime)
Disaster Level: Demon
The first regular monster to have his own arc. His impressive abilities matches even S-Class heroes.
- Acid Attack: He can spit globs of powerful acid.
- Alien Blood: He bleeds blue.
- Authority Equals Asskicking: He's the leader of the Sea Folk, and is by far their strongest member.
- Battle in the Rain: For once, it serves a purpose other than just being dramatic: the rain actually increases the Sea King's power significantly.
- Cool Crown: Goes with being King.
- Combat Pragmatist: Outmatched? Target an Innocent Bystander, a little girl no less, instead of the hero and force them to take the acid glob.
- Elemental Absorption: Water. While he can survive out of water for extended periods of time, he shrivels into a smaller, albeit still formidable, form. Being exposed to water allows him to hulk out into his true form, which is enormous and far more powerful.
- Healing Factor: While shown to be highly resistant to attacks, the Sea King is capable of recovering from his injuries at an extreme rate, as seen when an injury he received from Genos, an S-Class hero, healed while they were still fighting.
- I Am Not Left-Handed: After curb-stomping Pri-Pri Prisoner in a fight, he reveals that he had been fighting in a weakened dehydrated form the entire time.
- Knight of Cerebus: Deep Sea King's episode is consistently darker than anything before or since in an otherwise lighthearted series, personally managing to defeat every single hero that has enough confidence to face him, in which 2 of them are low-ranked S-Class heroes. and instilling a greater sense of dread within the narrative. That is until Saitama finally decides to face him...
- Lightning Bruiser: Strong enough to curb-stomp Puri-Puri-Prisoner and fast enough to keep with Sonic's speed.
- Macho Camp: ...Maybe. Has a style of speech that is unmistakably stereotypical camp. It's also why his 'dehydrated' form has hearts for nipples. Also a weird example of Adaptational Sexuality, as because it's only hinted at through his style of speech and not any kind of content or actions, this aspect of him is difficult to translate (eg: fan translations). Thus, while their fight is obviously an Expy Mirror Match in Japanese, and gives slightly more weight to Puri-Puri-Prisoner's having taken his advice, this aspect is completely lost on foreign audiences.note
- No Celebrities Were Harmed: Keith Silverstein does a pretty good Tim Curry impression for the English version.
- One-Winged Angel: His more humanoid form is the result of him spending an extended period of time out of the water and dehydrating. The rain (and the water in general) allows him to return to his much stronger original form.
- Overly Long Tongue: ...with mouth. He describes it as a moray eel, and given that he can still talk after Sonic slams his mouth shut and cuts most of it off, it might not be his actual tongue.
- Rapid-Fire Fisticuffs: He seems to have a preference for combo attacks, attacking his opponents mostly with a barrage of punches.
- Requisite Royal Regalia: Wears a regal crown and an ermine cape, but strangely very little else.
- Slasher Smile: Not helped by his very sharp teeth.
- Small Name, Big Ego: While he's not a small name and is actually quite powerful, he thinks that he's the World's Strongest Man by virtue of being the king of the seas since all life originated from the sea, never mind that there are many more heroes and monsters out there that outclass him. Saitama quickly proves him wrong.
- Sorting Algorithm of Evil: Subverted. Despite being introduced later in the series and lasting longer, he's actually much weaker than previous monsters like Vaccine Man, Beefcake, and Carnage Kabuto. He only gets more screen time because he faced off against weaker heroes while Saitama was busy getting lost.
- Super Spit: He can shoot dangerous spit from his mouth that is extremely acidic, as it melted Genos' metallic body almost completely.
- Super Speed: He boasts an exceptional amount of raw speed, seen when he was able to sneak up on Lightning Max (whom had been observing him from a distance) instantaneously, catching the A-Class hero well off guard. Under the rain, he can even keep up with Sonic's speed.
- Super Strength: Comparable to an S-Class hero from the get-go, and it increases even further when in contact with water.
- This Cannot Be!: After getting a hole punched through him by Saitama, his final expression screams this before he keels over.
- Averted in the anime; one of his eyes is dangling out of its socket, and his face resembles a dead fish, implying he was killed instantly.
- To Serve Man: He wants to turn humanity into food supplies for the Sea Folk.
- Underwear of Power: His attire oddly consists of only a crown, a cape, and underwear.
- Wake-Up Call Boss: In the anime, he's the first villain to last more than one episode. He also defeats several other heroes including two S-Class ones, albeit the lowest-ranked ones.
- Weak to Fire: Downplayed, but Genos' flame-based weaponry seems particularly effective against him, even forcing him to resort to dirty tactics because he was losing the fight. While it's never said that he is weak to fire and you could make the argument that Genos' power simply overwhelms him, the Sea King relies on hydration to reach his strongest form, excessive heat may dehydrate him, thus sapping his strength.
- Would Hurt a Child: Oh yes he would.
Disaster Level: UnknownA mysterious and powerful being, it's the one who gave Homeless Emperor his powers.
- Absolute Xenophobe: It hates humans with a passion and wants them all dead, which is why it gave Homeless Emperor his powers.
- Expy: Of the Anti-Spiral of Tengen Toppa Gurren Lagann. Both hate humans with a passion for some reason, they both live in alternate dimensions and they even have a somewhat similar design and are both shown to be super powerful in comparison to everyone else except the main character.
- Greater-Scope Villain: It is possibly a God-level threat and probably the one behind all the events related to the Monsters, as it's implied to be the "God" of all Mysterious Beings.
- Humanoid Abomination: Appears as a giant humanoid with Creepily Long Arms, covered in scar tissue from head to toe and with no face.
- Only Known by Their Nickname: It is called "God" by Homeless Emperor, but we don't know how it calls itself.
- Super Empowering: Gave Homeless Emperor his powers, and took them from him as well. It may also be the source of Garou's powers.
- Walking Spoiler: This thing spells major villain in the future, is super important to the plot and so far only appeared in a few panels in the webcomic.
- You Have Failed Me: The reason it kills Homeless Emperor.
Groups and Organizations
SubterraneansA group of underground monsters bent on taking over the surface world. They are at odds with the Deep Sea Kingdom and the Sky King. The relationship between these groups are not explored as none survive the series long enough to become important.
- Back from the Dead: Resurrected by Phoenix Man in his battle with Child Emperor.
- Brick Joke: A couple of the resurrected creatures appears to be as big as the ones that Saitama dreamed about. Perhaps he just wiped them out too quickly.
- Dreaming of Things to Come: Not them, but Saitama has a dream about them taking over the surface world the night before they reveal themselves.
- Killed Offscreen: Apparently didn't submit to or were declared too weak to join the Monster Organization. (While Genus could have done it, he would know about the Monsters Organization's lair, which he doesn't, given where their corpses were found). Oddly, they were dumped into a deep pit of water instead of being fed to Orochi.
- Small Name, Big Ego: At least their king was. He thought he could take over the surface world, but given how small he was and how doofy he and his minions looked compared to their dream counterparts, they were definitely not strong enough to beat the heroes.
- Worthy Opponent: What Saitama declares them to be in his dream and the feeling was mutual. In reality, they are a case of Small Name, Big Ego.
- What Happened to the Mouse?: They lived underground and popped up in Z City where Saitama lives and where the Monster Organization eventually set themselves up. It was possible they could have moved and they don't come up later on in the Webcomic, but the manga shows their dead, rotting bodies in the flooded area of the monster's base. Phoenix Man's thoughts imply the Monster Organization had them killed.
House of EvolutionAn organization founded by Doctor Genus to pursue the goal of human perfection though artificial evolution. First antagonist fought by Saitama and Genos and easily annihilated by the master and his disciple. After being defeated by Saitama, House of Evolution becomes a takoyaki stand.
Voiced by: Miyuki Sawashiro (Japanese), Cristina Valenzuela (English), Adriana Nuñez (Latin American Spanish)
Debut: Chapter 5 (Webcomic & Manga), Episode 2 (Anime)
Disaster Level: Demon
A prototype mutant human-mosquito hybrid created by Dr Genus.
- Adaptational Attractiveness: Mosquito Girl in ONE's style is essentially a woman's head and upper chest stuck onto a mosquito body, with her arms and legs being far more shriveled and insectile. Murata designs her more as an attractive woman with mosquito features, with a defined lower body and even hips.
- Axe-Crazy: She's definitely quite gleeful about draining people dry to boost her strength, and when she fights, she really gets into it.
- Barbie Doll Anatomy: Her crotch isn't drawn at all, and her nipples only appear as subtle small bumps on her chest.
- Bishōnen Line: She looks less insectoid after her transformation. She was still cute before, though.
- Blood Lust: Well she is a mosquito, kinda a given and it's what powers her up.
- The Beastmaster: She can control a huge swarm of mosquitoes.
- Cute Monster Girl: Given her Adaptational Attractiveness thanks to Murata style.
- Drunk with Power: Somewhat. She seems suave, but after absorbing all that blood she becomes much more unhinged, complete with Slasher Smile and shrunken eyes. Either that or she was always that crazy to begin with and just attempted to hide it.
- Flies Equals Evil: There are more than enough mosquitoes at her disposal to drain her victims of literally all their blood.
- Full-Frontal Assault: She is stark naked, as you can see in the manga when her belly button is clearly visible, and she doesn't seem to wear anything other than having body-paint or body coloration.
- Glass Cannon: Very, very fast and powerful, shredding Genos easily — but he didn't seem to have much trouble with ripping her lower legs clean off.
- Karmic Death: Mosquito Girl gets swatted by Saitama, leaving a bloody stain on the wall (although the "death" part is debatable; see A Twinkle in the Sky below).
- Ms. Fanservice: As stated above, she is an attractive woman with mosquito features in the manga. In the anime she also gets various shots of her body and has a sensual voice.
- Nightmare Face: The flash of her face as she started transforming in the anime was of her making a giddy Evil Laugh with glowing red eyes while drawn in shaking pencil lines.
- One-Winged Angel: After injecting herself with blood, she become much faster and powerful.
- Paint the Town Red: In the manga, she's just swatted through a building. In the anime, her blood-engorged abdomen messily explodes, leaving a large smear on the side of the building. The DVD version (which is also the Adult Swim one) had her both splatter her abdomen on the building and getting swatted through the building.
- Shameless Fanservice Girl: She doesn't seem to mind that Genos sees her nude, or if anyone else would be around the city as she raids it. But then again, being part insect provides some degree of exoskeletal modesty.
- She's Got Legs: And Genos takes care of them. She gets better, after absorbing blood.
- Super Mode: After absorbing enough blood, she Turns Red, regenerates her legs and becomes so fast that not even Genos, who fought her on even footing before, could keep up with her.
- Super Prototype: Said to be just a prototype, despite being the second strongest monster of the House of Evolution after the transformation.
- The Swarm: A large mosquito swarm, which she uses to drain animals and people and absorb their blood.
- A Twinkle in the Sky: It's blink-and-you-miss-it, but a humanoid form can be seen right after Saitama's swat sends her hitting a building in all three media forms. Some fans base themselves on this to argue that she may have survived after all.
- Vampiric Draining: The blood that her mosquitoes suck is used to increase her own power, given that she herself is a mosquito person.
Voiced by: Unshou Ishizuka (Japanese), Mike McFarland (English), Miguel Angel Ghigliazza (Latin American Spanish)
Debut: Chapter 9 (Webcomic & Manga), Episode 3 (Anime)
Disaster Level: Dragon
The pinnacle of Dr Genus' efforts in creating a perfect human but was deemed too insane. He is the strongest being in the House of Evolution.
- Alien Blood: His blood is phosphorous green.
- Aura Vision: He is capable of visualizing Saitama's power as an overwhelming aura.
- Ax-Crazy: Extremely unstable. He is very intelligent, but has an insatiable blood lust and thus had to be locked up because he kept killing anything that got near him.
- Dub Name Change: The official translation refers to him as Carnage Kabuto, and he enters "Carnage" mode instead of "Asura" mode. Happens again in the Latin American dub, where he is called Asura Kabuto and the name of his second form is restored to "Asura mode".
- Elite Mook: He is an artificial mutant created by Dr. Genus of the House of Evolution and is by far their strongest creation.
- Freak Out: Has a minor one when he realizes Saitama is much, much stronger than he thought.
- Genius Bruiser: Despite his arrogance and violent temperament, he's actually very intelligent and observant. He immediately realizes how strong Saitama is when he attempts to attack him.
- Gone Horribly Right: The pinnacle of the House of Evolution's experiments, but has to be chained in the basement because of his madness.
- Hoist by His Own Petard: By accident. His Carnage Mode lasts for a week... but he mentions that it'll last "until next Saturday". Saitama realizes that means today is Saturday, which means he's missing bargain day at the local supermarket, motivation enough to reduce Carnage Kabuto to a smear.
- Lightning Bruiser: Enough to beat Genos to a pulp.
- Nonindicative Name: Aside from the horn, his body doesn't really based on rhinoceros. Rather, it's more like a rhinoceros beetle (''kabutomushi" in Japanese). The official translation even calls him "Carnage Kabuto" instead.
- Overly Long Tongue: In the anime. And he likes to remind the audience of it.
- Shout-Out: The green Tron Lines that it gains in the anime, along with its horn and purple skin during Asura Mode, make it look like EVA-01.
- Spider-Sense: He could sense just how dangerous Saitama is.
- Super Breath: Capable of reflecting Genos' incinerator back at him.
- Super Mode: Asura Mode. Of course against Saitama it doesn't help much, and he gets killed in one hit.
- Super Strength: He boasts a great amount of strength seen as how he was able to badly damage Genos with minimal effort in his base form.
- Super Speed: Despite his enormous size he boasts an exceptional amount of speed that he uses to attack his enemies before they can even react.
- Super Toughness: Completely unfazed from Geno's blasts or punches.
- Ultimate Lifeform: He was created to be this and certainly quite the Genius Bruiser. Also utterly insane and thus deemed a failure.
- Underestimating Badassery: Double Subverted. He freaks out upon realizing Saitama's stronger than he expected, but upon hearing about how Saitama got so strong, his disbelief and anger causes him to discard his assessment and use Asura Mode to attack. He should have stuck with it.
- Unstoppable Rage: The effect of his Asura Mode, declared to last an entire week. Leads to his undoing in a roundabout fashion.
Voiced by: Jiro Saito (Japanese), Paul St. Peter (English), Dan Osorio (Latin American Spanish)
Debut: Chapter 8 (Webcomic & Manga), Episode 2 (Anime)
Disaster Level: Demon
The second most powerful creation of the House of Evolution.
- Absurdly Sharp Claws: Sharp enough to slice entire buildings to pieces.
- Affably Evil: He politely waits when Saitama needed to shake dirt out of his pants.
- Bad Boss: Doesn't hesitate to slice weaker allies to pieces if they are in his way."Such is the law of the jungle!"
- Calling Your Attacks: "LION SLASH!" "METEOR POWER SHOWER!!"
- Expy: Of Leomon from Digimon who was also a bipedal lion with a similar color scheme. In fact Leomon was also known as "The Beast King", which comes from his "Fist of the Beast King" attack Beast King's "Lion Slash" seems to be referencing visually. It doubles up in the English version, where his voice actor did voice Leomon too.
- Eye Scream: Threatened to claw Saitama's eyes out. In the end, Saitama ended up waving his dismembered eyeball as a trophy.
- King of Beasts: A human-lion hybrid, although he is only the second most powerful member of the House of Evolution, not the most powerful. But, even though he is not more powerful than Carnage Kabuto, Beast King's status as the second most powerful member of the House of Evolution and Carnage Kabuto's status as a failure, this would mean he is the most successful experiment produced by the organization.
- Ludicrous Gibs: What Saitama's Consecutive Normal Punches reduce him to.
- No Kill Like Overkill: Beast King is the second strongest fighter of the House of Evolution. He got killed when Saitama used Consecutive Normal Punches. Saitama took out the strongest fighter, Carnage Kabuto, with just one normal punch.
- Smug Super: Somewhat understandably self-confident, due to his high power level.
Voiced by: Shota Yamamoto (Japanese), Kaiji Tang (English), David Camarillo (Latin American Spanish)
Debut: Chapter 7 (Webcomic), Chapter 8 (Manga), Episode 2 (Anime)
Disaster Level: Demon
A cyborg gorilla created by Dr Genus.
- Adaptation Expansion: Is spared by Saitama, but never shows up again. In the anime, it is revealed he works with Genus in his takoyaki stand. He reappears in the manga when Zombieman finds him and Genus.
- Bad "Bad Acting": Being legitimately threatened with death while mostly dismembered and shown the eyeball of the monster one rank above him in strength in his organization caused him to instantly drop his unflinching robotic persona and go into a state of panic. And then he got yelled at by Saitama for dipping back into the performance while providing an overly-long Info Dump on the House of Evolution and its creator.
- Curb-Stomp Battle:
- Gets quickly beaten by Genos in one of the battles where he doesn't lose a limb.
- In manga Chapter 78 though, he pulls this on Marshall Gorilla, an up-and-coming Tiger-class Monster that wanted to be promoted to Demon, beating him in one punch while out for groceries and having no understanding of what was going on or why, not unlike Saitama.
- Cyborg: He's the only combat cyborg in the House of Evolution.
- Exactly What It Says on the Tin: Well most monsters in the House of Evolution are like this, but he is well, essentially a gorilla in an armor.
- HeelFace Turn: Reappears alongside Genus in episode 11 of the anime, with the two of them cooking takoyaki and watching the events of the Alien Invasion on TV.
- Killer Gorilla: A cyborg gorilla that starts off as a villain.
- Know When To Fold Them: After Saitama shows him the lone remain of Beast King, he quickly gives up and begs to be spared.
- Robo Speak: He's just faking it because he thinks it sounds cool.
- Sole Survivor: He's the only monster of the House of Evolution to actually survive, surrendering to Saitama after seeing him hold Beast King's eyeball.Armored Gorilla: "Umm...I'm sorry, I'll answer all your questions, so please spare my life."
Voiced by: Yoshiaki Hasegawa (JP), Kyle Hebert (EN)
Debut: Chapter 7 (Webcomic & Manga), Episode 2 (Anime)
Disaster Level: Tiger
- Alien Blood: He bleed green
- Curb-Stomp Battle: His "fight" against Saitama is over as fast as it started.
- Brain Monster: His brain is visible, as it's in a glass dome on his head.
- Evil Laugh: Has a brief laugh after breaking into Saitama's apartment.Kamakyuri : Heh heh heh heh !
- Informed Ability: According to Frog-Man, he's one of the strongest monsters of the House of Evolution. However, due to the brevity of his appearance, we don't get to see any evidence of this claim.
- Killed Mid-Sentence: He crashes through the roof of Saitama's apartment, tries to says his name, and Saitama kills him before he could finish that sentence.
- Off with His Head!: Saitama tears off his head from his body with a punch.
- Slaying Mantis: Looks like a humanoid mantis and is (supposedly) a dangerous monster.
- Spikes of Villainy: He has small spikes on his shoulders.
- There Was a Door: He enters Saitama's apartment by making a hole in the roof. Saitama doesn't take it very well...
- We Hardly Knew Ye: Gets killed in his third panel and he didn't get the chance to introduce himself.
Voiced by: Shinya Hamazoe (JP), Ben Diskin (EN)
Debut: Chapter 8 (Webcomic & Manga), Episode 2 (Anime)
Disaster Level: Tiger
- Famous Last Words:
- Inferred Survival: Since he became A Twinkle in the Sky instead of the usual splatter. However, the computer screen listed him as deceased so it's less likely.
- Mole Man: He's a talking humanoid mole (although he's more mole than man, and mostly looks like a giant mole).
- Oh, Crap!: Twice; first when Saitama lays eyes on him as the sole surviving monster among the group he was dealing with, leading to:
- Screw This, I'm Outta Here!: Made his exit by tunneling like a madman through the underground... but Saitama dove into the dirt and FOUND HIM...
- Tattooed Crook: He has kanji tattooed on his body.
- Tunnel King: As a mole, this is naturally his primary ability. He's not good enough to escape from Saitama, though.
- You Have Got to Be Kidding Me!: Has this reaction when he sees that Saitama managed to find him underground.
Voiced by: Hiroki Gotou (JP), Kirk Thornton (EN)
Debut: Chapter 7 (Webcomic), Chapter 7 (Manga), Episode 2 (Anime)
Disaster Level: Tiger
- Curb-Stomp Battle: Gets defeated along with Slugrus by Saitama so quickly, Genos didn't even notice at first.
- Oh, Crap!: Looks rather distraught when he realizes Kamakyuri has been killed.
- Ludicrous Gibs: Surprisingly, it's not Saitama but Beast King who ends up killing both him and Slugrus in this way.
- Something Person: His name is "Frog-Man".
- Tattooed Crook: Has a tattoo on his shoulder.
- Those Two Bad Guys: He seems to form a villainous duo with Slugrus.
- We Hardly Knew Ye: Appears only in a few panels before dying.
- Yank the Dog's Chain: Somehow, he and Slugrus managed to survive an attack from Saitama himself... only to be accidently killed by Beast King a few moments later.
Voiced by: Kenta Sasa (JP), Chris Cason (EN)
Debut: Chapter 7 (Webcomic), Chapter 7 (Manga), Episode 2 (Anime)
Disaster Level: Tiger
- Curb-Stomp Battle: Gets defeated along with Frog-Man by Saitama so quickly, Genos didn't even notice at first.
- Eye on a Stalk: Being some sort of humanoid slug, he has a pair of long eyestalks.
- Ludicrous Gibs: Surprisingly, it's not Saitama but Beast King who ends up killing both him and Frog-Man in this way.
- Oh, Crap!: Looks rather distraught when he realizes Kamakyuri has been killed.
- Telepathy: Has some telepathic powers, allowing him to sense Kamakyuri's death.
- Those Two Bad Guys: He seems to form a villainous duo with Frog-Man.
- We Hardly Knew Ye: Appears only in a few panels before dying.
- Yank the Dog's Chain: Somehow, he and Frog-Man managed to survive an attack from Saitama himself... only to be accidently killed by Beast King a few moments later.
Dark Matter Thieves
A group of intergalactic invaders filled with some of the strongest species in the Universe, led by an alien called Boros. Having already conquered several worlds in the universe, Earth is their most recent planet to plunder.
Voiced by: Toshiyuki Morikawa (Japanese), Chris Jai Alex (English), Dafnis Fernández (Latin American Spanish)
Debut: Chapter 36 (Webcomic), Chapter 32 (Manga), Episode 10 (Anime)
Disaster Level: Dragon
A galactic ruler, who, just like Saitama, is extremely powerful and can defeat any opponent, but soon grew bored when he believed there was no one left worth fighting. When a seer informs him that someone could pose as a challenge to him on Earth, he travels there to battle this warrior.
- Aliens are Bastards: He orders his ship to level A-City completely. Why? Because it was there, and he had nothing better to do.
- Affectionate Parody: His character is almost entirely shout-outs to various Dragon Ball characters like Goku and Piccolo, so he's an Affectionate Parody of the series as a whole.
- Alas, Poor Villain: His death in the Anime is portrayed like this.
- Anime Hair: To go with the DBZ parody, he has spiky hair with bangs that frame his face.
- Aura Vision: He can literally see Saitama's power via an aura.
- Authority Equals Asskicking: He's the leader of the alien invaders and is naturally the strongest member.
- Battle Aura: Have you guessed he's the DBZ parody yet? It's so powerful that it destroys the area around him whenever he moves.
- Be Careful What You Wish For: He really wanted a exhilaratingly powerful opponent to fight, and he got one.
- Blood Knight: He really, really wants a good fight.
- Curbstomp Battle: Clearly capable of delivering these, as his character somewhat mimics a darker version of Saitama. Lampshaded by Boros himself in a melancholy sort of way while dying after a vicious one-sided battle against Saitama.
- Cyclops: Only has one eye — on his face at least, see Eyes Do Not Belong There below.
- Dangerous Forbidden Technique: Meteoric Burst, a Super Mode that amps ups his already impressive strength and speed but at the cost of putting tremendous stress on his body similar to anaerobic exercise. He usually only uses it to finish fights quickly.
- Disc-One Final Boss: He's the last major enemy faced in the first season of the anime. And after his death in the manga and webcomic, no enemy except Awakened Garou gives the same level of performance.
- Evil Counterpart: To Saitama as he is basically "a villain for fun". Both of them are incredibly overpowered to the point where they lose interest in their later battles, and search for a Worthy Opponent. Saitama does that by being a hero for hobby. As for Boros, Saitama put it best upon hearing his reason for attacking Earth...and punching him for it.Saitama: Are you stupid? You can't just go attacking other planets just to liven up your boring life. Even telemarketers wouldn't think of that.
- Explaining Your Power to the Enemy: Boros does this in a short break between his fight with Saitama, namely how he has the best Healing Factor out of all the species in his planet. He demonstrates this by regrowing the arm that Saitama managed to tear off.
- Expy: He's a mish-mash of various Dragon Ball characters. Mainly, he's got bits of Frieza (Evil Overlord, big battleship, Quirky Mini Boss Squad, restrictive forms, The Prophecy) combined with bits of Goku (Anime Hair, questing for a stronger opponent, a glowy Super Mode that makes his hair grow bigger and gets compared to anaerobic exercise) and Piccolo (big pointy ears and regenerating limbs). In the anime version his cape, baggy pants, and regenerating From a Single Cell are also reminiscent of Majin Buu's. Interestingly, he has also some traits in common with later Dragon Ball villain Beerus, notably the prophecy which brought him to Earth to find a suitable opponent, destroying worlds for a hobby, and of course his similar name.
- Eye Beams: Shoots his energy blasts out of the eye on his chest.
- Eyes Do Not Belong There: A big eye on his chest.
- Face Death with Dignity: Accepts his loss against Saitama with dignity, having a civilized talk with the man about everything before dying, and acknowledging he never really had a chance against Saitama.
- Galactic Conqueror: He claims to be the ruler of many planets.
- Good Thing You Can Heal: Thanks to his regenerative powers, he survives multiple punches from Saitama.
- A Good Way to Die: How he feels about his loss against Saitama, since it was what he always wanted: a battle against a worthy opponent.
- Healing Factor: Apparently has the best of his entire species. Because of it, he's the first villain to take multiple punches to kill, capped off with a Serious Series punch, and even then he lingers long enough to deliver a final speech before kicking it. He even manages to almost instantly pull himself together from a barrage that reduces everything but his eye to a thin red paste.
- Humanoid Abomination: At first, Boros looked more human and had a steel-plated looking armor with a skull-looking ornament. His design was later changed by Yusuke Murata in order to look more alien.
- Invincible Villain: Not so much in the series itself, but he was alluded to being the final boss of ONE's earlier work "Sun Man" where he was far too powerful for the hero to defeat. Also deconstructed, as a lifetime of easy victories prior to meeting Saitama made him numb to any sense of accomplishment.
- Ironic Echo: At the height of his battle with Saitama, you can hear his heart beat in a way that mirrors Saitama's mole-people fantasy from the first episode.
- Kamehame Hadoken: His Planet Buster Roar Cannon, which fits in his being an Expy of Dragon Ball characters. He also has a weaker variant that vaporize whole cities.
- Knight of Cerebus: His entrance into the story shifts the light-hearted nature of the manga a little. Just a little, though. Oh, and he's the first villain to survive a normal punch from Saitama. Subverted when, as he lays dying, he accuses Saitama of not fighting seriously the whole time, although his arc still changes the mood of the story for the darker due to the sheer devastation it causes.
- Lightning Bruiser: The strongest opponent Saitama had faced at that point, strong enough to kick Saitama to the Moon and fast enough that the shockwaves from moving around were wrecking his ship, and durable enough to survive an extended fight with Saitama's Normal Series.
- Mr. Fanservice: He very muscular, attractive despite being a Humanoid Alien and gets a lot of lower back shots due to fighting in the buff.
- Not So Different: He's a powerful being who, after becoming the strongest being in his home planet, fell into a depression because there was no one left worth fighting.
- Omnicidal Maniac: He destroyed most things in the galaxy all because he was bored of not having a Worthy Opponent and attempted to destroy the Earth all so he could beat Saitama.
- Person of Mass Destruction: He does more unintentional damage to his own city-sized spaceship while fighting Saitama than everything the S-Class heroes hurl at it deliberately. He also claims his ultimate attack could wipe out all life on the Earth's surface.
- Power Makes Your Hair Grow: In Meteoric Burst, making him look like a Super Saiyan 3.
- Powered Armor: His armor channels the powers he was born with, and also acts as a Power Limiter. Destroying it—which Saitama does with his first blow — just makes his power go out of control, energy wise.
- The Prophecy: The entire reason he came to Earth? Some alien prophet predicted there'd be a worthy equal to be his opponent for him there. He finds his opponent alright, but Saitama is in his own league. But Boros doesn't mind, because he got the duel he dreamed of.
- Pulling Themselves Together: He gets punched into an eye and a smear of blood, thanks to Saitama's Consecutive Punch Combo, and manages to pull off this trope by sheer strength of will.
- Rubber-Forehead Aliens: Ironically the only non-human things about his looks are his blue skin, pointy ears, sharp teeth, and single cyclops-like eye.
- Super Mode: His "Meteoric Burst" form. It is Boros' trump card which he resorts to when he wishes to settle a fight quickly. He uses his latent energy to boost his body to speed and power beyond its limit, at the cost of putting immense burden on his body and even shortening his lifespan. This also completely changes his appearance.
- Super Speed: Boros has immeasurable speed and agility, as he was able to keep up with a casual Saitama. He uses the latent energy shunted from his body as a means of propulsion, making him so fast to the point that his path of movement often zig-zags, and anything he touches while moving at this speed instantly evaporates.
- Super Strength: Boros displays extreme amounts of strength during his fight against Saitama. He was also able to knock Saitama through several pillars with only one punch, the alien's various strikes easily damaging the place.
- Super Toughness: Boros is shown to be amazingly resilient, to the point of being the first opponent of Saitama to survive, after being hit directly by his punch, despite having his full powers sealed by his armor.
- Superpower Lottery: Boros was gifted with superpowers since the beginning and vastly increased his powers with time and experience. He claims that he in particular, possesses regeneration, physical ability and latent energy that far surpasses others, including members of his race.
- Volcanic Veins: Appears on him when his power-limiting armor is broken, letting his immense energy run loose. He then gets what amounts to a "color-inverted" version when he uses Meteoric Burst, along with a Power-up Full Color Change — that is, the parts of his body that used to be dark and non-glowing are now glowing a bright white, while the formerly glowing veins now seem to be glaringly dark in comparison. Here's how the end result of Meteoric Burst looks.
- Victory Is Boring: The entire reason he became a galactic conqueror was in the hopes that one day, he'd find an enemy worth fighting.
- Villain Respect: Boros is so far, the only villain who actually took Saitama very seriously, knowing just how strong he was with a single glance. He is also the only villain who gives massive respect to Saitama, viewing him as a Worthy Opponent. Even when he loses, Boros doesn't mind because Saitama gave him the exciting fight he always wanted.
- Villainous Valor: During the later part of his fight against Saitama even when it becomes clear that all of his attacks up until this point have done no damage, he continues to use Meteoric Burst despite the massive strain it puts on his body, and even after he gets pulverized completely he pulls himself back together with visible effort and defiantly declares that he will defeat Saitama while preparing his ultimate attack for one last stand despite all the damage he's taken so far.
- Wave Motion Gun: His Planet Buster Roar Cannon, which channels all his energy into a planet-killing beam.
- World's Strongest Man: One of the two strongest non-Saitama character in the series, with strength, speed, durability, and energy projection several orders of magnitude above the strongest S-Class heroes and Dragon-class monsters; with the other being Awakened Garou
- The Worf Barrage:
- He immediately proves how he's on a completely different level compared to the previous antagonists in the series when he gets back up after getting punched by Saitama. It's a downplayed example though since he still took quite a bit of damage from it.
- He's later on the giving end of a Worf Barrage when his ultimate attack, Planet Buster Roar Cannon, is blown away by Saitama's Serious Series: Serious Strike.
- Worthy Opponent: To Saitama, for being the first person to ever last long enough to legitimately exchange blows with above his bare minimum strength with later examples being of Garou and Tatsumaki, both of whom are humans that he went to great lengths to fight with non-lethal force and attempt to talk down from continued combat. He is the first opponent to survive a single punch of Saitama and leaves such a strong impression that Saitama tries to comfort him as he dies, mourns over his last breath, and in the anime expresses disgust when he fights a Dragon level threat the next day that can't also No-Sell his typical One-Hit Kill. Saitama purposely gave Boros an exciting fight, because he sympathized with him and knew exactly what it felt like to be so powerful that nothing is exciting anymore.
Voiced by: Kouki Uchiyama (Japanese), Vic Mignogna (English), Jorge Ornelas (Latin American Spanish)
Debut: Chapter 34 (Webcomic), Chapter 31 (Manga), Episode 10 (Anime)
Disaster Level: Dragon
One of Boros' 3 generals. A powerful shapeshifting and regenerating alien with 5 split personalities.
- Achilles' Heel: Each head has a small marble-like brain which allows them to regenerate endlessly. If a marble is destroyed, the associated head melts instantly, and Melzargard dies once they're all destroyed. This is mitigated somewhat by the fact that he has multiple heads and can freely move his brains within his body. However, his regeneration always begins with his heads, meaning that the brain can be easily found if his body is completely destroyed and forced to regenerate from scratch.
- Catchphrase: "That is good!".
- From a Single Cell: He can be reduced to a pile of chunks, but as long as his brains survive he can rebuild himself in seconds.
- Hypocrite: He constantly insults the Heroes for being fragile targets, ignoring the fact he would have been killed instantly by an A-Rank Hero if not for his regenerating abilities.
- Lovecraftian Superpower: He can freely control the shape of his body, from separating into one body for each head, merging all of his heads and bodies into a single form, and shapeshifting his limbs into any weapon he needs.
- Multiple Head Case: Each head possesses a different personality and speech pattern. One speaks in broken, simplistic language; another is analytic of things happening around Melzargard; another one is violent and suggests killing everything; one only praises the other heads by saying their ideas are good; and the final one seems to be in charge, taking action based on what the others say. It should be noted that the fewer heads Melzargard has, the more developed its speech patterns are.
- Nightmare Face: With all five heads combined, it has stacked pairs of eyes and multiple layers of teeth.
- Oh, Crap!: Gets an amazing one when Metal Bat grabs one of his brains.
- Shapeshifter Weapon: He can form all kinds of weapons, including axes, hammers, spikes or just a mass of tendrils.
- Smug Snake: Repeatedly taunts the S-Class heroes on how their attacks are useless due to his regeneration, only to slowly lose control of the fight once they figure out his weakness. He later claims that the S-Class heroes would die instantly if he focused solely on attacking them, only to be shocked to find that Bang wasn't hurt from his attack. It's also noticeable that he only lands two hits on his whole fight (one on Ia-Ian and one on Silverfang), and the latter doesn't even do any actual damage: despite his claims about his strength, he's only able to get beaten over and over again by the heroes until they find a way to kill him.
- Unskilled, but Strong: What's mainly dangerous about him is his incredible attack power and how his regeneration allows him to shrug off most attacks.
- Villainous Breakdown: With each head he lost, he lost his head some more, going from a Creepy Monotone to a rambling and cackling lunatic.
Voiced by: Shinya Hamazoe (Japanese), Bill Rogers (English)
Debut: Chapter 36 (Webcomic), Chapter 32 (Manga), Episode 10 (Anime)
Disaster Level: Dragon
- Acid Attack: He has acidic breath, although he does not get a chance to demonstrate this before Saitama literally knocks his block off.
- Elite Mook: According to Geryuganshoop, he was the top fighter in Boros' army. However, given that he was unlucky enough to run into Saitama, we don't know what he really is capable of.
- Eyeless Face: It's just one big mouth.
- Hollywood Acid: His breath which he claims can melt anything.
- Killed Mid-Sentence: Has his head punched off by Saitama while he was in the middle of bragging about his acid breath.
- Smug Snake: He gets pulverized by Saitama just as he was bragging about how powerful he is.
- We Hardly Knew Ye: When you run into Saitama it tends to happen.
- Xenomorph Xerox: He's an alien with an Eyeless Face, More Teeth than the Osmond Family and additional mouths who can emit acid, all of which are very reminiscent of the Xenomorph.
Voiced by: Hiroki Gotou (Japanese), Brian Beacock (English), Emmanuel Bernal (Latin American Spanish)
Debut: Chapter 36 (Webcomic), Chapter 32 (Manga), Episode 11 (Anime)
Disaster Level: Dragon
One of Boros' 3 generals. He is a telepathic and telekinetic alien in charge of the ship's controls.
- Bad Boss: Saitama is not affected by his gravity warping in any way, but we do see a couple of unfortunate mooks that happened to be within range get squished like pancakes, showing that Shoop is not all talk. And that he doesn't particularly care about his allies.
- Boom, Headshot!: How he dies. Saitama flicks a rock through his head.
- Death by Irony: He attacks Saitama by telekinetically hurling lots and lots of rocks at him, to no effect. Saitama kills him by tossing just one rock at him.
- Everything's Squishier with Cephalopods: Just a head with a bunch of tentacles.
- Gravity Master: Using his telekinesis, he can increase the force of gravity. This would have been impressive if his opponent were anyone but Saitama, who isn't even affected by it.
- Mission Control: Seems to be his role on the alien ship.
- Mind over Matter: Claims to be the most powerful telekinetic in the universe.
- Oh, Crap!: Continually as every attempt to stop Saitama fails. Has a more comical one when Saitama trolls him by saying he's lost and then going in the opposite directions Geryuganshoop gives him.
- Squishy Wizard: He is very good at annihilating most opponents before they can get into melee range, but a simple pebble splits his head in twain. It should be noted that the pebble was thrown by Saitama, but it still gives off this impression.
- Smug Snake: Calls himself the greatest telekinetic in the universe. Saitama is unimpressed, though, and his shown feats are not even on level with those displayed by Tornado of Terror (admittedly, he may be holding back to avoid at least obliterating his own ship if not his allies).
Monster AssociationA group of monsters led by Orochi and Gyoro-Gyoro that aim to destroy both the Hero Association and humanity to make a world where monsters reign supreme. They are the main antagonists of the Human Monster Saga (Monster Raid, Super Fight, and Monster Association arcs specifically). See their page.
The OrganizationA mysterious technological faction seemingly made up of robots. Their only known members so far are two unnamed robots who attempted to kill Hammerhead for stealing battle suits from them, Machine God G4, which was sent to fight King, and G5, which was sent to join the Monster Association as their representative.
- Bond Villain Stupidity: They don't bother to check if Hammerhead is really dead, which allowed him to survive.
- Brain Monster: One of them has his brain stored in a glass dome on his head.
- Cyber Cyclops: One of them is a robot that seems to only have one red eye.
- Killer Robot: What they seem to be. They fail to kill Hammerhead though, but they don't know that.
- Out-Gambitted: As it turns out, Hammerhead stealing and using their combat suits was part of their plans all along. In reality, they deliberately allowed him to do so because they wanted to collect real battle data.
- No Name Given: For now at least, we were not given any names for them.
- Those Two Bad Guys: A pair of villainous robots that appears to work as a duo.
- You Have Outlived Your Usefulness: They only let Hammerhead alive after he stole their combat suits so he can test those for them. After his defeat and the destruction of the suits, they come to kill him since he's no longer useful to them. Unbeknown to them, he actually survives their attack.
Debut: Chapter 42 (Webcomic), Chapter 37 (Manga)
Disaster Level: Demon
A self-proclaimed "Machine God" sent by the Organization to test King's combat ability.
- Beam Spam: G4's true form does this to Genos in their fight.
- BFS: Wields a massive sword that can be retracted from its giant chakra wheel on its back.
- Cyber Cyclops: Its Mecha form has a single eye.
- Mecha: It turns out to be a small robot piloting a large mecha.
- Requisite Royal Regalia: It wears a fur cape, has a giant crown and is decorated with shiny ornaments.
- Sadistic Choice: It gives King an ultimatum; if he does not fight, it will kill 10 civilians each minute.