- -Kei introducing himself to the reader
Kei Kawade was an ordinary kid living in Atlanta when the Terrigen Mists swept through his hometown, triggering his latent Inhuman genes and causing him to undergo Terrigenesis. When he emerged from his cocoon, he appeared to be unchanged, causing Kei and his parents to go back to their normal lives. Unbeknownst to them, Kei obtained the ability to summon any monster he can draw, making him a tremendously powerful individual who unintentionally started a global crisis.
- Afraid of Their Own Strength: Kei is appropriately wary of the destructive potential of his ability, but it begins to eat away at him by the time of the second series, to the point that he begins consider himself a monster due to what he's capable of.
- Alliterative Name: Kei Kawade. Also, Kid Kaiju
- Appropriated Appelation: Kei's hero name/callsign, Kid Kaiju was an on-the-spot invention by Miles Morales while the pair were fleeing from monsters.
- Art Initiates Life: In addition to summoning monsters, he is seemingly able to create his own monsters, creating Fireclaw, Mekara, Hi-Vo, Aegis, Slizzik, and Scragg to battle the Leviathon Mother. However, this is called into doubt in Monsters Unleashed II, with the monsters themselves remembering times before coming to Kei's aid, but are unsure whether or not this had to do with their creation or if they were instead summoned from somewhere else.
- Book Dumb: Shirks his study sessions with H.E.R.B.I.E. to hang out with his monsters instead, but is fairly resourceful and capable when the time calls for it.
- But Not Too Foreign: His mother, Deanna, is Caucasian. His father, Minouru, is Japanese-American.
- The Chosen One: It's later revealed that Kei is similar to an ancient Inhuman queen who shared his ability to communicate with and summon monsters, being destined to finish what she started and defeat the Leviathon Mother. According to Karnak and Medusa, sometimes when Inhuman civilizations (including those of alien races) are under threat, a special Inhuman is empowered for that threat - Kei and the Inhuman queen are of that nature.
- Civvie Spandex: He doesn't have an official hero costume, just wearing his hoodie, jeans, and sneakers while riding into battle. Justified in that he's not doing much of the fighting himself.
- Combining Mecha: His ability to combine his monsters pays mind to this trope, with Smasher heavily resembling a mecha. The allusion is complete with a "cockpit" for Kei to sit in and observe Smasher's fight while giving them new weapons and powers to use.
- Depending on the Artist: The artists can't seem to decide on an eye color, flip-flopping between brown and blue.
- Destructive Saviour: Kei and his monsters can level entire city blocks accidentally and did so while capturing Animax, leading them to get an earful from Damage Control soon afterward.
- Distressed Dude: Modok 2.0, Mr. Sinister, The Mad Thinker, and The Leader have Kei kidnapped in order to exploit his power. He's also captured by Poison Fing Fang Foom, who attempts to force Kei to summon the rest of the Poisons into the mainstream Marvel Universe.
- Evil Is Not a Toy: Not all of the monsters Kei summons are friendly and the story makes it clear that there will be very dire consequences if Kei were to ever use his power thoughtlessly, which he takes great lengths to avoid. In addition, less savory individuals would love to force Kei to use his power to wreak havoc.
- Fan Boy: Admits to being obsessed with monsters, drawing them constantly with all sorts of monster-related paraphernalia being scattered around his room. He even reads Outlandish Monsters magazine, which lets him recognize Elsa Bloodstone instantly.
- Friendless Background: Due to his fascination with monsters and drawing, Kei doesn't have a lot of friends, citing his monsters as his only real friends he can speak with freely.
- Godzilla Threshold: He is considered one by SHIELD and Damage Control, not being authorized to mobilize against anything less threatening than a swarm of giant bees, a nuclear meltdown, or an incoming of Eldritch Abominations .
- Goo Goo Godlike: His power is noted by H.E.R.B.I.E. to potentially be the most powerful force on the planet for good, with Kei's random doodles being able to preoccupy every major superhero organization on the planet simultaneously, but he's still just an eleven year old kid.
- Hero Insurance: Although he's kept under Damage Control's protection, they explicitly keep tabs on him to avert this trope, knowing that his Kaiju can cause billions in property damage a day if allowed to stop everyday crooks due to how destructive they are.
- How Do I Shot Web?: Due to getting his powers relatively recently, he hasn't exactly had time to explore the full breadth of his abilities, with many aspects of his powers taking him completely by surprise, like the time he accidentally summoned Moon Girl along with Devil Dinosaur. It's also heavily implied that his ability isn't limited to monsters, but they're simply what he draws the most since they're what he's interested in. He also says that superheroes are much harder for him to draw.
- Innocently Insensitive: The "Learning Curve" arc has Kei realizing that he hasn't taken the time to get to know his monsters aside from occasional chats, leading him to agree to work on actually being a friend rather than a Kid with the Leash.
- Intelligible Unintelligible: His ability allows him to understand anyone who he's at least partially drawn, allowing Kei to understand what Groot was actually saying while Rocket Raccoon was trying to interrogate Kei.
- In the Hood: Is rarely seen without his trademark hoodie.
- Kaiju: The namesake for his hero name, his primary power allows him to summon colossal creatures to do battle.
- Keeping Secrets Sucks: When he discovers when that he's be subconsciously drawing the Poisons into his notepad, he hides the fact from everybody out of fear of what they might do to him. This backfires spectacularly when he accidentally draws Poison Fing Fang Foom in the dirt, summoning the monster into the Savage Lands. Elsa calls Kei out on this accordingly.
- Kid Hero: He's just eleven years old and is still in elementary school.
- Kid With The Remote Control: Subverted. While Kei's own original monsters are loyal to him (though they will occasionally voice their grievances about how he's interacting with them), any monsters he summons are under no obligation to help him and can outright refuse to do anything or even attack him if he isn't careful. Even while "piloting" Smasher, the fusion of his original monsters, he doesn't actually control Smasher, simply drawing him new weapons and powers while shouting advice from the safety of Smasher's "cockpit". He sometimes manages to get around this by asking for "favors" (i.e. asking an alien conqueror to allow Elsa to borrow his atomic war hammer for a brief fight), but Kei still has to tread lightly around his power.
- Limited Wardrobe: He's rarely seen without his trademark hoodie.
- Living MacGuffin: His power's incredible capability for heroism and destruction make him a person of special interest for government agencies like SHIELD, villainous organizations like the Intelligencia or the Poisons, as well as the Inhumans due to the origin of Kei's powers. The resulting pressure makes him reluctant to trust any of those organizations, who all want to use his powers for their own goals.
- Mon: The most frequent usage of his power involves him drawing a monster to help out by fighting whatever is in front of him. These monsters can be tremendously powerful, with each one of them being able to level a city on their own if left to their own devices. This also crosses into Olympus Mons, as many of the monsters he summons, especially his own creations, are incredibly powerful with high-ratings on the official Marvel Power Grid, requiring entities as powerful as Thor or Hercules to take down. However, this is also a Deconstructed Trope, as the monsters make it clear that they only help him when it suits them (even threatening to devour him the next time they meet) and entities like Fing Fang Foom don't enjoy it at all, finding it embarrassing to be bossed around by a child. Even his own monsters voice their complaints about their treatment, staying that they sometimes feels that Kei treats them like weapons or tools rather than sentient beings, making him strive to get to know them better.
- Nice Guy: Kei is a sweet and compassionate kid who is willing to risk life and limb for others and is almost never seen raising his voice or otherwise being unpleasant.
- Performance Anxiety: Gets increasingly anxious and doubtful of his own abilities as the invasion continues, with his monsters getting beaten back faster than he can summon them. He gets over it with some encouragement from Moon Girl, Queen Medusa, Miles Morales, and some other superheroes.
- Pre-Mortem One-Liner: Right before having Smasher cut down the Leviathon Mother.Kei: Sorry, Leviathon Mother, I'm cutting your trip to Earth short!
- Realistic Diction Is Unrealistic: Averted. Kei speaks as you would expect an eleven year old to in the 21st century, with all sorts of slang, improper contractions (i.e. somebody's to combine somebody + is), Buffy Speak, and other modern syntax.
- Required Secondary Powers: His abilities wouldn't be nearly as useful if he wasn't as good at drawing as he already is. In addition, his powers don't come with skilled judgement about how and when to use his monsters, leading SHIELD to attempt to school Kei in every potentially useful subject they can, from advanced combat strategy, to xenomorphology, to terrigen chemistry, to beginning Kree.
- Ship Tease: With Moon Girl. Lunella is quite affectionate towards Kei and constantly encourages him in the worst of times. It helps that both kids are within the same age range.
- Squishy Wizard: Functionally he's this, having a monumentally powerful ability, but little to no combat potential on his own.
- Summon Magic: What his power amounts to, allowing him to summon powerful monsters to the battlefield where they'll (hopefully) help him out against whatever he's fighting.
- Summoning Ritual: In order to use his abilities, Kei needs to be able to draw on something, whether it be a notepad, a computer screen, or sand.
- Synchronization: Kei seems to have some kind of link with his original creations. If any of them get seriously injured or killed, as was the case for Fireclaw, Kei will suffer physical pain and even a nosebleed.
- Thinking Up Portals: Kei can open rifts that teleport his monsters anywhere he can draw them, serving as the basis for his power. This is also useful for getting himself out of sticky situations, since he'll be transported with them if he stays near them upon being transported.
- Unwitting Instigator of Doom: His doodles and Inhuman ability led to the start of the Leviathon invasion.
- -Elsa before slaughtering a den of vampires in Romania
Elsa Bloodstone is a world-renowned monster hunter and a leading expert in cryptozoology. She is the first to realize Kei's importance in the face of the Leviathon invasion and is later hired as his personal bodyguard and trainer in between her regular hunts for dangerous vampires, werewolves, and other deadly creatures of myth. However, even she is a little out of her depth when it comes to dealing with an eleven-year old with the power to summon monsters the size of skyscrapers with a notepad.
- Face of a Thug: They're all heroic individuals, but their massive size, inhuman appearances, and capacity for destruction don't win them many favors. Especially prominent with Scragg, Hi-Vo, and Slizzik. Scragg's Large Ham tendencies and speaking of the follies of those who need saving tend to scare more than help, while Hi-Vo and Slizzik are not humanoid at all and can't speak up for themselves (at least in any way a normal human can understand).
- Kaiju: Massive alien beings of unknown origin that boast monstrous power.
- Mysterious Past: They seem to be original creations of Kei, since they're new monster designs he's never seen before, but they have vague memories of societies they lived in before being summoned by him. Either way, they're bonded to him in ways no other monsters are.
- No Indoor Voice: Due to how large they are, their voices are booming even when they're calm. As a result, they're always rendered in all caps.
- Olympus Mons: Are treated as this, with all of them having incredibly high ratings across the official Power Grid. For reference, they were the only ones on Earth able to put up a fight against the Leviathon Mother during the invasion, after the latter literally curbstomped the Totally Awesome Hulk, and each has the power to level a city with ease if left to their own devices.
- The Smurfette Principle: Of Kei's Kaiju, only Mekara is explicitly female in design.
- Synchronization: They share some sort of link with Kei that causes him to feel pain and suffer a Psychic Nosebleed should any of them be seriously injured or even killed. In addition, their power is proportionate to Kei's own will. If he's suffering from self-doubt, self-loathing, and guilt, their power wanes considerably.
- The Voiceless: Slizzik and Hi-Vo can't speak like their compatriots, with the former roaring like a dragon and the latter making crackling and popping noises.
A boisterous mech-like being with incredible speed and a nigh-indestructible chassis, Aegis is the de-facto leader of Kei's Kaiju after Fireclaw fell in combat against the Leviathon Queen.
- Blood Knight: Loves a good fight, but Kei refuses to summon monsters just for Aegis to beat them up, afraid that they'll be cross with him in the procerss.
- Boisterous Bruiser: Loves to mock his foes and boast about his size and strength.
- Book Dumb: Scoffs at schoolwork, saying that it's more important to learn from fights than textbooks.Aegis: Feh. Books and homework and math problems and overrated anyhow. School of hard knocks. That's where you really learn something.
Mekara: What do you know about school, Aegis?
Aegis: I know if I had gone, I would have been the biggest, toughest kid in my class. Aw, come on. Where are all the big sharks?
- Humongous Mecha: His design.
- Manchild: Is the most outwardly childish of Kei's monsters, catching great white sharks with his bare hands when he's bored and using all sorts of colloquialisms.
- Mechanical Lifeforms: Is robotic on the surface, but can eat food like any other organism.
An aggressive, tiger-like humanoid, he was the first of Kei's "original creations" to appear and charge at the Leviathon Mother, serving as the leader of Kei's Kaiju. However, he is soon offed by the Leviathon Mother in frustration, throwing the rest of the group into disrepair until Kei himself took the reins.
- Boisterous Bruiser: Spends most of his screentime yelling about how he's going to beat the crap out of the Leviathon Mother.Fireclaw: Fireclaw says big monster momma is no match for us!Mekara: You guys! You guys! Do you feel it? We're real! We're real and winning/triumphing/conquering!Fireclaw: Of course, Fireclaw is winning! Fireclaw was made for this!
- Impaled with Extreme Prejudice: How he dies, being speared through the heart by one of the Leviathon Mother's claws.
- The Leader: Was the de facto commander of Kei's Kaiju until the Leviathon slayed him.
- Panthera Awesome: A tiger-like humanoid who led the charge against the Leviathon Mother, with Kei referring to him as his "best guy", having the highest strength and fighting skills out of Kei's creations according to the Power Grid.
- Red Is Heroic: Brightly red in color and brave enough to charge into battle against the Leviathon Mother.
- Third-Person Person: Only refers to himself in the third person.Fireclaw: Fireclaw wants big monster momma to leave Earth alone! Fireclaw wants to destroy her!
Aegis: Whatever you say "Tryger"!
Fireclaw: Don't call Fireclaw that! Fireclaw is Fireclaw!
- We Hardly Knew Ye: He's offed not even a full page after his introduction, revealing the risks that come with Kei's creations.
- -Hi-Vo's usual noises
An enormous electric lizard-like creature with the ability to absorb energy and emit it lightning, proving exceptionally helpful when dealing with dangerous power sources.
- Blue Is Heroic: Is good-natured and bright blue.
- Intelligible Unintelligible: Hi-Vo can only speak through buzzing, whirring, and popping noises, but the other monsters (and Kei) can get the gist of what he means. Thanks to Lunella's translator he's now able to communicate verbally, although it turns out he's something of a Motor Mouth.
- Lightning Bruiser: Although not as physically powerful as Kei's other monsters, Hi-Vo is still incredibly strong due to his sheer size. In addition, he boasts a 7 for both speed and energy projection on the official Marvel Power Grid, the highest possible ratings.
- No Conservation of Energy: Averted. Hi-Vo is explicitly able to convert one type of energy to another, being able to turn dangerous radiation into electricity for him to use harmlessly, allowing him to diffuse a nuclear power plant that was about to go critical.
- Shock and Awe: Can absorb and emit lightning from his body.
- Yellow Lightning, Blue Lightning: Hi-Vo's is blue.
- -Mekara to a bunch of smaller monsters
A mechanoid giantess, Mekara brings the heat to Kei's team, packing all sorts of lasers, missiles, and weapons while having the greatest overall physical strength.
- Humongous Mecha: Like Aegis, this was the basis for her design.
- Mechanical Lifeforms: Is robotic on the surface, but can eat food like any other organism.
- Superhero Packing Heat: Is armed to the teeth with missiles, lasers, swords, and buzzsaws, being one of the only two members of Kei's team with built-in artificial armaments.
- Women Are Wiser: While Aegis goofs off and Scragg is a Large Ham, Mekara reminds Kei that his studies are important and explicitly calls him out on him treating them like toys rather than getting to know them as friends.
- Verbal Tic: Has an unusual vocal glitch in which she sometimes spouts off synonyms with a word. For instance, if she wanted to say that she was angry, she'd probably say she was angry/furious/enraged. She is somewhat embarrassed of it, and it's due to nervousness from how disorderly the others are compared to the order she's used to.
- -Scragg's first words upon entering the fight against the Leviathon Mother
One of Kei's six "original creations", Scragg is a giant, vegetarian insectoid who would love nothing more than to settle conflicts peacefully, but he has more than enough muscle to to finish a fight if he feels that it's the only way to settle it.
- Animal Talk: Scragg can communicate with other insect-like creatures, but he's admittedly rusty due to being away from his hive for so long according to him, which leads to complications when he and Kei are sent to deal with a swarm of giant bees. Ultimately subverted by the end of that story, since they resort to using the bees' own preferred form of communication, body language and movement, to get their point across.
- Big Creepy-Crawlies: Heavily resembles a number of insects, including stinkbugs, beetles, dragonflies, and praying mantises.
- Boisterous Bruiser: Frequently refers to himself with adjectives like "Mighty" and "Terrible".
- Gentle Giant: Scragg is very warm and loving despite his frightening appearance and size.
- Insectoid Aliens: Says that he remembers being part of a hive of creatures just like him, where they lived in peace and harmony.
- Large Ham: NOTHING Scragg does is short of over the top. He's even hammy while eavesdropping on a conversation.Scragg: The awesome might of eavesdropping will peacefully reveal the dire secrets these humans hold!
- Martial Pacifist: Scragg would much rather settle a conflict through peaceful conversation than get into a fight. But he's still one of the most powerful creatures on the planet and won't hesitate to use his power if he deems it necessary.
- The Minion Master: Can quickly spawn swarms of smaller, beetle-like creatures the size of a small dog that follow his every command, being able to chew through nearly anything or quickly evacuate dozens of people at a time.
- Sesquipedalian Loquaciousness: He speaks with needlessly verbose language much of the time.
A green, fire-breathing dragon. That's all we really know about Slizzik, since he can't speak like his fellow monsters.
- Breath Weapon: Breathes fire.
- Instant Awesome: Just Add Dragons!: The only dragon-like entity of Kei's Kaiju.
- Intelligible Unintelligible: Aegis, Mekara, and Scragg are able to translate Slizzik's roars into English.
- It Can Think: While his being sentient has never been a surprise, Lunella's translator revealed he's a really casual guy who also seems to be something of a tech genius, instantly understanding the science behind her invention.
- Our Dragons Are Different: Slizzik stands on two legs and wears scale-like armor that covers his lower body. He can't speak, but he's quite intelligent, having a 5 on the Official Power Grid.
- -Fin Fang Foom making an entrance
Fing Fang Foom is a Makluan from the planet of Kakaranthara. Although his race is known for their shapeshifting abilities, Foom heavily prefers his form as an enormous, dragon-like creature. He was one of the first to be summoned by Kei during the Leviathon invasion, with his strength proving invaluable in repelling it.
- Badass Boast: Loves to make these, as shown by the quote above.
- Breath Weapon: Can breath fire.
- Call to Agriculture: While no friend of man, Foom largely just wants to be left alone and tend to his own matters, which include a farm and crops. After the defeat of his Poison counterpart, he comments he's going back to harvest his squash.
- Evil Is Not a Toy: Warns Kei to be very careful when summoning monsters, as they are likely to not be as friendly to him the next time.
- Genius Bruiser: Has a power ranking comparable to the Hulk at his peak, but he is actually fully sapient and was his crew's navigator before being sealed away.
- Kaiju: Easily Marvel's most famous example.
- Mirror Match: Is summoned into the fray once more to deal with his Poison counterpart.
- Our Dragons Are Different: Foom is an alien, not a dragon; but just so happens to look like one, having inspired the Chinese dragon legends.
- Pet the Dog: Although he makes it clear that he hates being ordered around by Kei, he is far from the murderous beast he usually is around the boy, offering him advice and valiantly battling the Leviathon Mother. When Kei's monsters are losing to Foom's Poison version, the original Foom gives him the pep talk he needs to turn things around.
- Rousing Speech: Gives one to Kei after his monsters are defeated by the Poison Fin Fang Foom, rejuvenating them and allowing them to win the fight.Foom: [telepathically] Hear me, Kid Kaiju. Open your mind to my thoughts. This creature you face... he is a pretender... but he seems to possess the same gifts I do... He has been using you. He has been influencing you from across time and space. He telepathically urged you to bring him to this world. He fed your uncertainty.. He weakened you... weakened the monsters you created.
Kei: Are... are you sure?
Foom: [telepathically] It's what I would have done. But you must be strong. You must fight that creature's influence. He knows what you fear. He knows you are terrified of becoming a monster yourself. And if you do not fight him... if you do what he demands... then that is what you will be. Your monsters were defeated because they draw strength from you. But they draw weakness from you as well. You can embolden them once more... if you throw off the yoke of his influence... if you cast away your own security. We all have the choice to be a monster or a hero. Believe me, I know this lesson well. It is an easy path to become a beast... and it only takes a few missteps... the simplest nudge to become a hero though... that takes confidence and determination... that I have witnessed from you first hand!
- Your Size May Vary: Partially justified as he is a shapeshifter, but his seemingly default dragon-like form can vary in size from being as around 10 meters to 50 meters tall. A bit more consistent in more modern comics however.
- Telepathy: Has this power, using it to give his Rousing Speech to Kei.