Monster Girl Encyclopedia

Imagine your typical RPG-style fantasy world, filled with monsters and adventure.

Now replace all of said monsters with Cute Monster Girls, and throw in huge amounts of Fan Service and outright sex. The Monster Girl Encyclopedia is a bestiary dedicated to cataloging all the different kinds of Cute Monster Girls in the world. The entries are filled with Fetish Fuel, and most are Not Safe for Work.

A compilation of translated entries for the Encyclopedia canon can be found here(needs registration in order to view the contents). New monster species are being added all the time by the original creator, and so the list linked above is not complete yet. Just go to either Danbooru or Gelbooru for the newest additions to the list ( which may not even be translated into English yet). A new -booru has opened recently thanks to the Monster Girl Unlimited staff: MonsterGirlbooru

Also see Living with Monster Girl for a Doujinshi series with similar content.
 * WARNING: The -booru sites contain NSFW material! Do not browse with touchy relatives present.
 * Kenkou Kurosu/Cross, the artist's, page can be found here.
 * Monster Girl Unlimited: The Group responsible for creating the English Translated Profiles. Also acts as a Fan Community. Requires registration to view.
 * Another much-smaller attempt at an Encyclopedia from apparently the same artist as the Living with Monster Girls series.
 * An alternate site is here: http://mjm202036.pbworks.com/Monster-Girls-Encyclopedia
 * And now, we have an actual Monster Girl Encyclopedia Wiki: http://monstergirlencyclopedia.wikia.com/wiki/Monster_Girl_Encyclopedia


 * Abuse Is Okay When It Is Female On Male: The Ogre is described as literally beating her partner into submission so she can carry him off in the first place, then beating him while having sex with him, and beating him even harder if he tries to fight back, though, as the profile describes them as pleasurable, it is uncertain whether "beating" is a metaphor for rough, passionate sex.
 * The Dark Elf, meanwhile, is clearly designed to appeal to the BDSM fetish and is noted as referring to her partners as "slaves". The setting is rather ambiguous about the details of this, though, and so there is quite a bit of debate as to what this involves (for example, is she an actual sadist?) and just how bad she is about doing what she does do.
 * A Date With Rosie Palms: The Roper, a parasite that causes its host to sprout Naughty Tentacles, lures in mates by stimulating the host's genitals, causing said host to emit noises that lure in their targets.
 * It is also said that if a colony of Devil Bugs cannot find a male victim, they'll resort to this. So far, nothing has suggested other mamono do it.
 * A Form You Are Comfortable With: Doppelgangers. They are shape-shifting spirits formed out of unrequited love, and turn into an idealized version of the woman their lonely male targets pine for. Subverted in that their true forms, short, flat girls in black dresses, are hardly maddening or awful.
 * Action Survivor: More like Sexual Survivor. The in-universe author of the encyclopedia managed to get deep into the Demon Lord's Castle and have an interview with her, and has encountered every monster present in the book. Sometimes he got attacked, but always "survived" (or at least, none have kept him as their husband) and continued working on the book. At the end of compilation book foreword, he notes that The Order is hunting him now so he's running to Zipangu. Since every entry after Lilim (the final entry in compilation book) are Youkai, it's obvious that he made it. Of course, since he's writing an encyclopedia and working to correct peoples misunderstandings toward monsters, the Demon Lord is most likely assisting him.
 * Alchemic Elementals: All four of them are featured as monster girls, though the Salamander is replaced by Ignis. It was later added to the encyclopedia as a subspecies of the Lizardman race.
 * All Chinese People Know Kung-Fu: The Hinezumi, from the Mist Continent, are said to "excel at martial arts". Likewise, the Ren Xiongmao are said to be good at using a Bo staff in martial arts.
 * All Women Are Lustful: Best case scenario. Some are not so much lustful as they are hungry.
 * Alice Allusion: For one, there's Alice-type succubi, the artwork for Wererabbit also has her carries a large pocket watch. There's even a bit of dialogue in the book about this, including a portion of the world called Wonderland.
 * In addition, the Alice emits a pheromone that makes men rape her, forcibly turning them into Lolicons. This, and her appearance as a young girl, is possibly a reference to rumors of Lewis Carroll being a Lolicon himself, to one degree or another.
 * Wererabbits can teleport their husbands to the Wonderland.
 * There are now several monsters based upon Alice in Wonderland characters, such as the Mad Hatter, March Hare, Dormouse...
 * The Alice likes to chase after and play with Wererabbits.
 * All Amazons Want Hercules:
 * Orc and Ogre are usually abusive toward their male slaves, but beat one in combat or during sex and she will become an obedient wife/slave herself. More pronounced with the Orc than with the Ogre.
 * Dragons have a tsun-attitude toward their husbands at first, treating them as precious treasures and refusing to let them out of their sight. They become full dere when they recognize the man as an "Alpha male," and become subservient to him.
 * Lizardmen, Proud Warrior Race Gals all, will propose marriage to whoever beats them in a duel. And they won't give up even if the man refuses at first, following him around and waiting for him to change his mind. Salamanders are much the same, just more Hot Blooded about it.
 * Baphomet, the most powerful demon-beasts, turn men into lolicons regardless of their strength, but will often only accept those who beat her in combat as husbands.
 * Averted by the Amazoness though. In their worldview, men are supposed to Stay In The Kitchen and only come out to be publicly raped by their horny "wives".
 * A Man Is Not A Virgin: Almost certainly not in this world. If he does subvert it, he'll have horny Unicorns trying to get him to become their husband.
 * Amazonian Beauty: The Minotauri & Jinko are ripped, but like pretty much all monsters are still attractive.
 * Ancient Egypt: Represented by Anubi, Sphinxes, Khepri, Apophis, Pharao and Mummies.
 * And I Must Scream: Some of the monsters do this:
 * Most plant type monsters will constantly keep their husband bound by vines or even turn them into part of the tree they reside in.
 * Some monsters will kidnap men and take them to Pandemonium where time is eternally still.
 * The Mimics, Jinns of the Jar and Charybdis lure men towards their hiding spot, and then suck them in an alternate dimension where they can be trapped forever.
 * Angelic Beauty: Applies to the Angel and all of her subspecies: the Valkyrie, the Houri and the Cupid.
 * Animate Inanimate Object: In a sense, both the Chochin-Obake (a lantern) and the Karakasa-Obake (an umbrella), due to being based on the tsukumogami. And also the Living Doll.
 * Anime Chinese Girl: The Hinezumi and the Ren Xiongmao. And probably all other monsters from the Mist Continent.
 * Anything That Moves: It's mentioned that zombies can't distinguish a man from a woman, and so they'll pretty much violate both indiscriminately.
 * The Archer: The Elf and Centaur are both drawn wielding a bow and arrow.
 * Art Evolution: There's quite a difference between the earliest entries and the newest, and quite a few versions have actually been redone graphically, sometimes with very visible changes (the Lizardman, for example, lost a few inches, got more detailed armor, had her hands changed into more bestial claws, and... gained quite a few inches back).
 * The Assimilator: Dryads; any man they catch will eventually fuse permanently with their tree, only able to die once the tree eventually dies.
 * Also the Matango. Their spores enter men's bodies and start changing their behavior, and once they (due to the spores) have sex with a Matango, they will turn into a Mushroom man themselves and permanently fuse with the Matango.
 * Atlantis Is Boring: Averted. Aquatic monsters are often just as lustful as those on land. And Sea Bishops can transform any man so he can live in ocean freely, though they only do this to either aquatic monster's husbands or drowning men with no other chance of survival.
 * Author Appeal: The artist seems to love Horny Devils, considering how many monsters have been corrupted by them. And let's not forget the number of monsters that convert other women into their species, or the number that can be turned into more submissive versions...
 * And the fact most of them want to rape you.
 * Pretty much all monsters without animal ears of some sort have pointy ears, presumably due to this reason.
 * Bee People: The Honeybees.
 * Better Than Sex: Fully Averted. There is nothing Monsters like more than sex.
 * Beware The Nice Ones: Jurogumo appear sweet and harmless during the day, but at night turn into a sadistic rapists which will almost invariably breaks their husbands' wills eventually.
 * Big Brother Attraction: A subversion. Though they're not related at all (usually), the lolis of the Sabbath all refer to their male partners as "Big Brother". This is probably just for cuteness value.
 * Bigfoot, Sasquatch and Yeti: The Yeti monstergirl. Here, they are very friendly creatures that love giving hugs to anybody. They save frozen travelers by heating them with their own high body temperature, and if a man were to hug them back, they would see it as the man courting them.
 * Bizarre Sexual Dimorphism: The end result of the Demon Lords plan would mean that humans and monstergirls are a single species with humans as men and monstergirls as women.
 * Blessed With Suck:
 * You're a man in a magical land full of Cute Monster Girls which, presuming they find you attractive, are all willing and eager to have sex with you? Sounds fun, except some of them can be less then attractive unless you're into the fetish they represent, many of them aren't very big on the concept of "No", and pretty much all of them are very possessive. But then again. Rape Is Ok When It Is Female On Male.
 * Plus, if you happen to have an abundance of spiritual energy, you're probably an extremely powerful person or a mighty wizard... and you're going to draw eager, hungry monsters like iron fillings to a magnet, regardless of your attraction to them or desire to attract them.
 * If you're a woman in this world, you can be turned into a Cute Monster Girl, gaining supernatural charm and beauty (along with other abilities). Unfortunately, not all of the potential transformations you can undergo are necessarily attractive to you (Roper and Dark Slime particularly), your personality changes when you are transformed (though there's a bit of a Broken Base on exactly how much is changed. See Draco In Leather Pants in the YMMV page) and, worst of all? Most of the monsters won't ask your permission first.
 * Blob Monster: The Slimes and all their variants. They're essentially living goop that takes on the proportions of an attractive woman. They tend to be not very smart, and if their mass increases too much, they'll split of part of themselves as a new Slime.
 * Blood Knight: The Salamander. She doesn't care really if a man wins or lose when he fights her. So long as he can give her the most enjoyable fight possible and prove to be her most Worthy Opponent, she'll follow him to the ends of the earth, publicly declaring her love for him, until he agrees to be her husband.
 * Blue Eyes: The Yuki-Onna has a stunning pair.
 * Blue and Orange Morality: The monstergirls have different standards than humans, but from their own perspective aren't evil at all. To them, sex is as important as feeding (which for some is the same thing), likewise to them Sex Equals Love, so they don't see anything wrong with raping a man they like. Especially since they still have the mindset of a predator, and tend to see human males as prey. Though there are a few who respect it if their husband is not in the mood. They are also hedonists who happen to be extremely depraved to the point where they don't condemn incest; so a monster child raping her father is not frowned upon, and often encouraged. Likewise, to them physical appearance doesn't matter, they only care if the man they seek is a decent person and has attractive spirit energy. However, they do (most of them at least) love their husband immensely and would never dream of leaving him and consider murder something unthinkable.
 * Bodyguard Babes: the Kunoichi are this to their husbands.
 * Body Horror: The Roper. A human woman infected with a parasite that causes her lower body to turn partly into slime and sprout long, pink tentacles.
 * Bottle Fairy: The Red Oni Red Oni lives to party and spends most of her life drunk or drinking.
 * Her cousin the Blue Oni is one too, just only when she's with a guy she likes.
 * Breast Expansion: The Holstaurs have the power to adjust the size of their chests at will.
 * From Fallen Maidens, this is usually happens when girls are converted into monsters.
 * Brought Down To Normal: If a doppelganger's husband see her true form, and love her as she is, she will lose her shapeshifting ability, since she can't be herself with it. Not that she'd need it anymore.
 * But We Used A Condom: Word Of God says that the monsters will end up poking holes in your condoms, or outright refuse to use them.
 * Came Back Wrong: Even the dead aren't safe from demonic energy. Their souls can be corrupted and become Cute Ghost Girls, while their bodies can be revived as ghouls, zombies or skeletons.
 * Career Killers: A subversion with the Mantis. They don't kill for money, but they are highly efficient hunters, nicknamed "Assassins of the Forest"
 * Cat Girl: The Werecat monster. Giving her catnip results in her raping you. Also comes in Ancient Egypt flavour with the Sphinx, Japanese flavour with the Nekomata and outright Furry with the Cait Sith.
 * Chest Monster: The Mimic and Jinn of the Jar are Cute Monster Girl embodiments of this. They pretend to be, respectively, a chest or a large pot, hiding in a pocket dimension within, but any man who messes with it is promptly "attacked". The Mimic pops out and uses magic to get the man to have sex with her, taking him back into the chest if she really likes him, while the Jinn of the Jar ucks him into the pot where her body unconsciously drive the man to have sex with her. Stick something into the Mimic's keyhole, or toss something into the Jinn's jar, and they'll leap out of their home and be helpless. Likewise, you can also just break the Jinn's jar, though this will leave them severely distressed.
 * Children Are Innocent: Subverted. Many of the monster girls are loli. The two biggest subversions would have to be the Alice and the Charybdis. The Alice subconsciously broadcasts a Charm Person spell that eventually Mind Rapes a man into raping her and becoming obsessed with following her as her lover. The Charbydis is the only monster girl to actively have gangbangs.
 * Double subverted by Alice, as her mind will remain innocent as her memory will get reset after the sexual encounter.
 * There is in fact an entire section of the Demon Lord Army filled with nothing BUT little girls, the Sabbath, who's motto is "To spread the charm and depravity of little girls!"
 * For a while, it looked like human children were off-limits at the very least. The artist never singled them out when it involved corruption, and even witches were believed to always lolified adults. This was until the Fallen Maidens book introduced a pair of corrupted orphan girls...
 * Cthulhumanoid: The Mind Flayer.
 * Clingy Jealous Girl: The Lamia and Medusa entries are noted to be quite possessive. The Lamia, in fact, hunts her husband (who may have been forced into marrying her) to the ends of the earth looking to strangle him to death if he cheats on her.
 * Charybdises don't take kindly to Scyllas scooping up men they've dragged, or are dragging, down beneath the waves, but are usually too timid to actually confront Scyllas about it.
 * The Shirohebi as well, though she has a non-violent solution to it. If she suspects her husband may be cheating on her, she'll use her magic to make sure his urges can only be satisfied by her.
 * Clone Degeneration: The Loli-Centric Sabbath created a special medicine to let Monster Girls live out gang-rape fantasies, the so-called "Doppleganger Medicine" (No relation to the MG of the same name). When given to their boyfriend, it splits said man up into numerous, sense-sharing clones based on how much is taken. However, the more clones there are, the more they all devolve into sex-crazed, bestial rapists for their girls' pleasure until the effects wear off.
 * Continuity Snarl: A lot, actually. A combination of different translators that don't always keep the correct meaning, outdated content, exxagerations, in-universe propaganda and statements of the author that don't always correspond with what's written in official materials make it difficult to determine exactly how to view the setting.
 * Corrupt The Cutie: Absolutely EVERYWHERE.
 * Chaste Hero: No matter how negative or apathetic your view on sex is, getting demonic energy forced into your body will turn you into a sex maniac monster girl/incubus. Followers of the Fallen God especially enjoy corrupting the chaste and virtuous, including Angels, while Succubi find corrupting the normally stubborn, fastidious Elves to be most entertaining.
 * Alice succubi can't remember anything about sex, so they mentally remain like innocent children. Their bodies, however, gradually become more and more responsive after each sexual encounter. And their "husbands" are often those who have had their Big Brother Instinct slowly turn in a rather different direction because of the Alice's natural charm magic.
 * Elemental monster girls are curious about sex at first, but they're relatively tame compare to most monsters. However, as they continue to have sex with their contracted elementalists, the will slowly become corrupted by demonic energy, eventually turning them into sex maniacs. Furthermore, since they're elementals, their corruption will pollute the natural elements of the nearby physical world as well, transforming it into a fragment of the Demon Realm.
 * Background story of the fairy kingdom note how fairies were just innocent children who love fun games and sweet. It went offrail when they befriend pixies and imps, as their magical energy got mixed and become succubi. Then pixies and Imps teach fairies about sex with humans, claim that it's just another fun and addictive game...And it's true, not to mention the spirit energy is the best sweet the fairies ever taste. Their mindset remain as innocent children, but the behavior change greatly.
 * The Corruption: Basically, demonic energy makes everything either monster girls, some kind of succubus, or physical embodiments of lust (elementals). Also makes everyone horny beyond measure.
 * Counting Sheep: The Weresheep has enchanted wool which makes those who come into contact with it drowsy, including the Weresheep themselves.
 * Covered In Gunge: The various slime monsters' preferred method of catching men.
 * Covert Pervert: The Sea Bishop, who doesn't even actively seek out a husband and only gets one when she has to transform him in order to save him from drowning, secretly takes notes from the couples she marries and, once she has transformed a drowning man, eagerly pounces him to try everything she's learned with him.
 * The Nightmare is a inversion of this. She appears as strong-willed and lustful woman in her victim's dreams to assault her target, but the real Nightmare is extremely timid centaur-subrace which will get paralyzed with fear simply by getting touched in the real world. But, as time passes, she'll become less and less covert.
 * Crapsaccharine World: The changes that the Demon Lord makes causes the land itself to become benevolent towards it's inhabitants instead of apathetic and the Demon Energy means that everyone is HOT. Though this may seem like a great universe to live in there are several elements of Fridge Horror to the series. Rape happens so often that it's not even considered particularly negative, some of the monster girls trap their husbands in And I Must Scream situations, Demon energy screws with peoples heads, most of the gods are jerks or outright evil and if the current Demon Lord is killed, the universe will fall back into a vicious cycle that nobody benefits from.
 * Cuddle Bug: The Yeti love giving hugs to anybody. However, they especially like it if someone hugs them back.
 * Cute Bruiser: The Goblin is a loli who happens to be several times stronger than a fully grown man. Now in Oppai Loli variety with the Hobgoblin.
 * Also Baphomet, the most powerful demon beast, and the leader of the loli-cult called the Sabbath.
 * Cute Clumsy Girl, Dojikko: Hobgoblin. To quote her entry "However, perhaps because the enlarged portion of their bodies robs them of nutrients, they're often slower in the head than normal goblins. They're simpler than goblins, and perhaps because of the weight of their huge breasts, nowhere near as agile. When the goblins who formed a gang chase the man around, they're always the ones lagging behind. They're often observed falling down during the chase too.".
 * Cute Ghost Girl: Naturally.
 * Cute Monster Girl: Goes without saying. The entire purpose of the Encyclopedia is to catalog each and every one, and considering the number of monsters in popular culture, it isn't even half done yet.
 * Cute Witch: The Witch entry, natch. And all of them are loli.
 * Dark Skinned Blond: The Amazon, Dark Elf, Jinn of the Jar, Dryad, Girtabilu, and Ghoul all have dark skin and light colored hair.
 * Death By Sex: Amazingly enough, totally averted; none of the Horny Devils will explicitly kill you.
 * Additionally translated settings information from the author's website states that monster girls never kill their mates, as they need men to reproduce and all genuinely love their husbands).
 * Deus Sex Machina: Originally, even the Demon Lord stood no chance against the Chief God. However, since the current Demon Lord is a succubus, she gained immense power by having sex with her husband, an ex-hero-turned-incubus. When the Chief God decided to deal with the Demon Lord by herself, the couple had more than enough power by that point to badly injure her.
 * Did You Just Punch Out Cthulhu: Mentioned above, the Demon Lord and her husband beat the Chief God, successor of the creator of the setting's world.
 * Difficulty Spike: Mention in the background materials. Heroines starting their quests have a much easier time of it than heroes, since most monsters in the mortal realm have no interest in women. Things change for the worse in Demon Realm, where most monsters now have a distinctly Anything That Moves attitude and Tentacle Forests will violate any human girls that wander too close. The worst part is, since female humans draw spirit energy from their environment, they will slowly absorb the demonic energy of Demon Realm instead and will become succubi should they stay in the Demon Realm for too long. Heroes will have much less steep difficulty spike: every monster will be trying to get into their pants from the start, but they will gain spirit energy by eating and resting, and so far, there is no word that tentacles necessarily have any interest in males, so there may not be any new challenges in Demon Realm as long as they can repel monsters and have supply of clean food, save that they will encounter more monsters, and more powerful types thereof.
 * Distressed Damsel, Standard Hero Reward : Subverted. Often, when there is a maiden being held captive in a dungeon, it's very likely to be Echidna in disguise, waiting for a strong man worthy to be her mate.
 * Dracolich: If a Dragon dies without taking a human mate, she will be resurrected as a "Dragon Zombie." They generally have the same disposition as humans turned into zombies, i.e. endlessly craving sex.
 * Dumb Muscle: The Wurm is said to have immense strength and durability, as well as unlimited stamina. They are even said to uproot entire forests just because they were in the way. However, they are as dumb as bricks.
 * Eldritch Abomination: A passing hint was given in background story about the sea, about Demons of Chaos, a group of demons with power beyond the gods that were sealed away at the bottom of the ocean. A dark place that isn't ruled by Poseidon and no normal monster dares go near. They too, might have been changed into women, but this remains unconfirmed.
 * Elemental Embodiment: The Gnome (Earth), Ignis (Fire), Sylph (Wind) and Undine (Water) monster-girls. Also overlaps with Horny Devils, as they're also partially embodiments of pure "demon magic"; if they have enough sex, they become "corrupted" and start broadcasting it, transforming all the men and women within miles of them into incubi and succubi.
 * The Lava Golem is a Lava Elemental, though it's not said if they also have the power to change their environment.
 * Elves Versus Dwarves: Even the ones that have been turned into succubi tend to snipe at each other and fight over men. For some reason, succubi elves and dwarves usually target same men. Fortunately, their "fighting" consist mostly of squeezing the man between themselves.
 * Embarrassing Tattoo: A subversion. Many Monster Girls have intricate, quite stylish tattoos across their bodies (often featuring the MGE's trademark heart-symbol). The MGE book revealed these to be "Pleasure Runes", a magic which ups the sensitivity of any Monster Girl to pleasure. The larger and more covering the tattoo, the more sensitive they become. Though this has the side-effect of making it... difficult to go out, when the slightest touch can bring you to your knees, quivering in pleasure. For this reason only monsters that have abandoned living regular lives like Dark Angels cover a large portion of their body in such tattoos.
 * One of the Sabbath's most impressive accomplishments was research which allowed them to engrave the tattoos on clothes, letting girls remove the sensitivity-increasing runes if they wished. It also let the Sabbath cover themselves in more than their small bodies would normally allow.
 * Empathic Shapeshifter: Doppelgangers. Affection-based. See A Form You Are Comfortable With
 * Enthralling Siren: A kind of Harpy with a beautiful singing voice. They wear clothing reminiscent of an Idol Singer and share similar traits with other harpies.
 * Erotic Eating: A subversion with the Ghoul. Her mouth has evolved to be so sensitive, that it's considered a sex organ all it's own, so anytime she puts something in her mouth is either masturbation or sex.
 * Everything's Better With Cows: Holstaur. To quote her entry "She, even as a child, develops nutritious milk. This milk increases the amount of spirit a man has, and promotes great health. This is of great demand among monsters, in order to make their husbands stronger and healthier, and sells very quickly, even among humans. She produces enough milk, that two people can live off of it alone.".
 * Everything's Better With Monkeys: Averted with the Kakuen. They're intelligent, yet selfish, Jerkassess and very lustful.
 * Everything's Squishier With Cephalopods: The Scylla, Kraken and Mind Flayer.
 * Everything's Worse With Bears: Usually averted by the sleepy, dopey Grizzly monster, as long as she hasn't been noshing on Honeybee honey.
 * Expy:
 * The way Pixies dress is very similar to the Shin Megami Tensei Pixie.
 * As a heroine, Wilmarina from Fallen Maidens looks suspiciously like Miki Sayaka.
 * Baphomet seems to based on her monstrous counterpart from Ragnarok Online.
 * Kunoichi has been compared to the Ninja from Disgaea quite often.
 * Face Full Of Alien Wing Wong: An Inverted Trope - monsters do rape people, but because its Female On Male, the action goes the other way around where monsters reproduce by impregnating themselves with human males.
 * The Fair Folk: Sort of. Fairies & Leanan Sidhe aren't malicious unless a Succubus is involved. Played straight with the Pixies, however, who are actually typed as "Demons" rather than "Fairies".
 * Fairy Sexy: All the varieties of fairy might count to one degree or another, though many are child-like. The Titania, however, certainly counts. Their beauty is even described as "breathtaking".
 * Fallen Angel: What happens when Angels get corrupted by succubi. At first, the corruption twists their minds into thinking that sex is a proper reward for good deeds done by mortals. For a time, they still believe that they're doing holy work, rewarding good-doers with pleasure using their body. Eventually however, they will realize their own desire and fully transform into dark angels.
 * Downplayed with the Houri and Cupid. As servants of Eros, they're already so much like monsters in mentality that corrupting them hardly makes any noticable difference.
 * Fallen Hero: Demon Lord's army has whole units made up entirely of examples of this trope. Just like the Fallen Angel above, these people were heroes who failed their mission to slay the Demon Lord. Men have been charmed and women made into succubi, and they have now reformed their parties under the command of the Demon Lord. Although they're probably the most powerful fighting force in Demon Lord's army, the former heroes are usually too busy screwing their heroines and only see actual combat when it represents a serious threat to the Demon Realm. Finally, the Demon Lord's husband is a mighty hero who may have slain the previous Demon Lord. But considering his motive, it's arguable if he's really fallen.
 * The primary subject matter of the latest book released by the artist of the series, titled: "Monster Girl World Guide: Fallen Maidens".
 * Fan Girl: The Shirohebi becomes this to the man she falls in love with. She'll follow him around showering him with love and affection until he caves and gets with her.
 * Also the Nureonago, but she's more devoted and docile than the Shirohebi.
 * Fantastic Arousal: Many monster-girls, naturally, have extremely bizarre turn-ons and ways of showing it.
 * Fantasy Kitchen Sink: Dragons, Mummies, Slime, Oni, Harpies, and that's just to get you started. And I do mean ALL kinds of fantasy.
 * Fantasy Pantheon: So far, we have The Chief God (who seemed to based on the Abrahamic YHVH, although background settings revealed that it's really a title and the current Chief "God" is a recently appointed goddess), Poseidon (who governs the oceans), Ares (a war goddess), Bacchus (goddess of Alcohol), and Eros (love goddess) (all goddessess), Bastet a Cat Goddess, and the Fallen God (who resides in Pandemonium).
 * Fantastic Racism: The pure elves consider humans, dwarves and any monsters to be lowly creatures and loathe to make contact with them, so they rarely get far from their Hidden Elf Village. Dwarves feel insulted by this attitude and hate them back. Meanwhile "Execute on Sight" warrants are issued, and monsters are hunted wherever The Order has strong influence, with exceptions for the Elemental family (minus Dark Matters) since they're considered "High Elementals" and not monsters.
 * Fauns and Satyrs: The Satyros; they're followers of the God of Alcohol and do pretty much nothing exept drink and brew wine, play their flute, and have sex.
 * Fiery Redhead: The Ignis is not only this, she's literally on fire.
 * The Salamander too, especially if you give her a good fight.
 * Fisher Kingdom: The Demon Realm. It's full of demonic energy, so anyone inside will become more lustful over time. And women naturally draw in energy from their surroundings when they expend it doing anything from fighting or casting magic to just breathing (as opposed to men and monsters, who only recharge from their own souls by eating and resting). When her spirit energy is completely depleted and replaced by demonic energy, she becomes a Succubus. Of course, by that point, she'll probably already be caught and transformed by a Succubus, a Vampire, a Dark Slime, a Dark Matter, or turned into a Roper after wandering into the Forest of Tentacles, or any one of a hundred other things...
 * Flower in Her Hair: Trolls, due to the fact that flowers tend to grow on their bodies. Also the Fairies.
 * Freakiness Shame: Trolls are sensitive about their oversized hands & feet, and try to cover them with flower decorations.
 * Fully-Clothed Nudity: Inverted. Many monsters are actually naked, using retractable fur or scales to preserve their modesty.
 * Gag Boobs:
 * The massively well-endowed Holstaur uses her breast size as a form of communication. If she presses her breasts against you, it means she likes you. If she presses them against you firmly it means she wants sex. Now. They can even change size. Likewise, if you rub her breasts while she does this, she'll see it as returning the affection and will be very happy.
 * The Holsty's breasts are so impressive that even the loli-fication magic of the Sabbath cannot shrink them. Any attempts at turning a Holstaur into a loli have resulted in oppai-lolis. This was performed by the Baphomet Leader herself, and she consider it a personal Epic Fail.
 * The Hobgoblins are inferior to normal Goblins in every way except strength. They're The Ditz and Dojikko, yet ordinary Goblins will follow them around because they think "bigger breasts are amazing."
 * Garden Garment: While Trolls have flowers growing on their bodies, they also decorate themselves with foreign flowers. It mostly to draw atttention away from their large hands & feet, as wel as cover up their strong body odor.
 * Gender Bender: Undead monsters are always female. No matter what gender the living body used to have. The more self-aware ones will even have warped memories: you might remember your best friend from when you were a guy as a lover.
 * The Alp is a Succubus that was once an Incubus. A Homosexual Incubus. Their desire to be with men was so great, they (sub)consciously transformed themselves into a monster-girl.
 * Can also happen with guys who are in the closet, whether they know it or not.
 * Genius Bruiser: Baphomets. They're leaders of the Sabbath cult (see Mad Scientist below), and are stated to be the most powerful demon beasts as well.
 * Getting Smilies Painted On Your Soul: Anyone twisted to suit the Demon Lord's purposes, male or female.
 * The Ghost: So far, we've yet to see any of the major characters from the background setting info, like The Demon Lord and Poseidon.
 * Ghostly Goals: Subverted. It's said that ghosts can go to heaven should their business on Earth be done. However, in this world, all ghosts share the same goal, to keep having sex with the guys they like.
 * Giant Spider: The Arachne, the Jorogumo and the Ushioni. The first is your basic "woman's upper torso where the head should be on a Giant Spider", who is something of a bondage-dominatrix due to being aroused when men struggle. The second is a more Japanese-themed version of the first, who acts as a Yamato Nadeshiko by day but at night turns into a sadist who rapes the man she has her eyes on so badly his will is broken and he is reduced to a spineless minion. The last one, having the lower torso of a giant tarantula, is the only one to have inhuman hands, is a violently lustful wandering rapist-monster-girl, has a Healing Factor, and is the only one of the "Arachne" family who can transform human women into more of her kind through a method other than sex.
 * Go Karting With Bowser: Even The Order tolerate aquatic monster girls. Since they're the only things to guarantee safe sea voyages (Poseidon won't summon storms against a ship if there is a monster's husband among the passengers) and the aquatic monsters are good guides. Likewise, Kobolds are also tolerated as they are mostly harmless pets. Mostly.
 * In fact, Posideon's entire reason for siding with the Demon Lord in the first place is that (s)he didn't like having to kill humans at sea as instructed by the Chief God.
 * Godiva Hair: The Alraune, Nereid and Kejourou. Though in the latter's case, it's Justified.
 * Golem: The ones appearing in the Encyclopedia are made as statues with the forms of attractive women, though more mundane golems are mentioned in their entry. Should a golem fall in love with a man, she will remove the control runes that dictate her behavior on her own, then rewrite them to ensure her lover becomes her new master.
 * Good Is Not Nice: Read Jerkass Gods entry below. It's hard to admit, but while the system enforced by previous chief gods is really cruel, it did keep the world in balance state for a very long time.
 * Gorgeous Gorgon: The entire Encyclopedia probably qualifies, but the Lamia, Medusa and Echidna are the most literal examples.
 * Green Thumb: Trolls can cause plants to grow in even the most hostile of environments. They even have flowers growing on their body.
 * Happiness In Slavery: Both the Chochin-Obake and the Karakasa-Obake, due to being tsukumogami, desire to be "used" by men more than anything. Though how friendly they are depends on how they were treated when they were still lifeless.
 * Hard-Drinking Party Girl: Both the Red and Blue Oni's practically live exclusively off of sake, and love to hold drinking parties. Likewise the Satyros, being followers of the God of Alcohol, pretty much spend their entire time drinking wine, making music and having sex.
 * Harem: While they themselves are always faithful to their single husband, most monsters have no problem sharing a man if they love him equally. Some, like Werewolves and Goblins naturally do this while others, like Lamia, are very opposed to it.
 * Harem Seeker: The Bicorn, as opposed to the Unicorn, actively tries to form a harem of monstergirls to satisfy their husbands.
 * The Hedonist: Pretty much all mamono are by nature only interested in pleasure of any kind. Wether or not they have standards when it comes to that or not is pretty unclear.
 * Hellhound: Yes, there is one. Said to be so ferocious not even gods can tame one, though like all monsters have a lot of affection towards their husband.
 * Hermaphrodite: The giant slug species used to be this. The roper may also be considered hermaphroditic, seeing as how they use their tentacles to reproduce.
 * Hidden Buxom: If you look closely at the newly done version of the Yuki-onna you can tell that she's just as stacked underneath that kimono as the rest of the monstergirls.
 * High School AU: There are five spin-off profiles, "Succubus Eroge Heroine", which depict archetype Eroge highschool girls of modern world turned into succubi.
 * Horny Devils: Not only is there the basic Succubus, there's also multiple different variants. The Alice is a mutant Succubus that looks and thinks like a pure and innocent young girl, but she exudes a mind-warping aura that eventually causes any man too close to lose his mind and rape her -- despite the fact she doesn't want him to or even really desire sex of her own. For added insult, after the sex, she forgets all about it even as her body is restored to its virgin state. The Amazoness is basically a Hot Amazon Succubus with an appearance that invokes Nubile Savage that lives in a society that is one part Boobs Of Steel to one part Amazon Brigade. Dark Priests are Succubi-like demons that attempt to convert men to worship of the "Fallen God" through preaching and sex, dressing up in sexy nun outfits to boot. Imps aren't Succubi, but have adopted the same approach despite their childish appearance.
 * All of the creatures in the Encyclopedia are either being influenced by Succubus magic (Elves, Angels), or were outright created by it (Dark Elves, Dark Angels).
 * On the other end, Lilim (who are the direct biological children of the Demon Lord) are basically super-succubi, able to do all of the things that other succubi can on the mere virtue of being damn sexy (no magic or effort required). However, they somehow also inherit their mother's preference of monogamy.
 * Hot Amazon: Suprisingly not the Amazoness unfortunately. However, the Jinko and Minotauress are both very muscular Amazonian Beauties.
 * Hot Blooded: The Salamander, somewhat literally as well as metaphorically, and the Ushi-Oni in a dark, twisted kind of way.
 * Human Mom Nonhuman Dad: Inverted. All of the monster races depend on human males to reproduce. The background material proclaims that this inversion is the core of the current Demon Lord's plan for peace; though she doesn't yet have enough power to make monster-girl couplings produce anything other than more monstergirls, she intends to make it so that they give birth to human sons as well. In essence, humans and monsters will become different sexes of the same race.
 * I Am Legion: Slime Queens, who need to produce slimegirl-like subunits because they're too large and slow, and will sometimes grow to resemble large villages of slimes (even trading with other villages!). Needless to say, woe to any man in their sights.
 * I Just Want to Have Friends: Wererabbits. They're described as "lonely", and if they make a friend, they will not ever want to be separated from them. It's even worse if the rumors that Wererabbits can die of loneliness are true.
 * I Love The Dead: Played with. Here,the dead love you.
 * Imprinting: What determines if a man becomes a monster's chosen husband. Any ceremonies are just for show.
 * Interspecies Romance: A rather explicit (and not necessarily consensual on the male side) version, but the basic principle behind the setting.
 * Instant Awesome Just Add Ninja: Succubi Kunoichi, who have been compared to the Disgaea Ninja many, many times, and become Ninja Maids if they "Assassinate" a high-profile target.
 * It Amused Me: The Fairy Queen does nothing to stop the corruption in her kingdom, she thinks it's much more fun this way.
 * Jekyll And Hyde: The Jurougumo. During the day? The sweetest, nicest girl you could hope to meet. At night? A sadistic, raging, rape-happy nymphomaniac.
 * Technically the Holstaur as well. Ordinarily sweet, gentle and placid, they become savage, brutal and as lusty as their Minotaurus cousins if they keep looking at the color red or go too long without sex.
 * Also the Weresheep. Normally, they're quite calm and friendly, but that's only because of the tranquilizing effect of their own magical furs. Once their fur is shaven off, they become very vicious.
 * Trolls as well. Normally they're friendly and harmless. But if they spend too much time in sunlight, the plants on their bodies cause them to become very horny and even stronger than normal.
 * Jerkass Gods: The Chief God may really love humans, but her (the current chief god is female) hatred of monsters only serves to justify the extremism of the new Demon Lord. She's apparently unwilling to accept the changes to the monsters done by the new demon lord, having created them with the intent of having a tool to keep mankind's population from growing out of control. On the other end of the spectrum, the Fallen God takes the new Demon Lord's philosophy Up To Eleven (or rather, was apparently retconned into fulfilling the Demon Lord's original role). He/she/it believes in pleasure above all other things, and forcefully converts both human women and angels into its followers the same way as a succubus, causing them to desire the ultimate "reward" of being locked in eternal coitus with their mate in Pandemonium. Lastly, the Demon Lord, who is often compared to a god in the setting material, is arrogant, vain, and certain that her solution is the only valid plan for peace, no matter how many humans have to be FORCED to agree.
 * The cyclopes were once deities, but some fellow deities cursed them into monster simply because they had only one eye.
 * Translations of the official background material have also shown that Poseidon (who is a goddess in this setting) turned against the other gods and sided with the demon lord in part at least because the other gods were forcing her to make storms to reduce human populations and make them fear the sea.
 * Also from the Official Settings Material, it turns out that the monsters are living creatures the Chief God created so that the population of humans could be easily controlled. The previous Demon Lords? They were control devices so that the gods could control the monsters. Whenever the population of humans got too high, the monsters would become incredibly vicious and begin killing large numbers of humans. Then when humans started to die out and the monsters became too numerous, the Chief God would grant humans incredible power, creating “heroes”, and send them to slay the Demon Lord. With the Demon Lord slain, the monsters would kill each other to decide the next Demon Lord, causing a rapid decrease in the monster population. This would go on until humans again became too prosperous, at which point a new Demon Lord would be born and take control of the Monsters. This process ran for several cycles until a Succubus fought her way to becoming the current Demon Lord, and started messing with the system.
 * Kimono Fanservice: The Yuki-Onna and Inari look great in their kimonos, but the Jurougumo and Youko look drop-dead sexy.
 * The Shirohebi, Ryu and Kejourou look lovely in theirs too. The Nureonago as well, in a way.
 * Knight In Shining Armor, Black Knight: Dullahans wear black armor, but morally they split the difference. To date, they're the only monsters that have been stated to fight out of loyalty to the Demon Lord rather than a chance to grab a husband and quit, demonstrating a knightly alignment. Morally... well, let's not get into that.
 * Knight Templar: The Order. In order to prevent mankind from falling to corruption, and to keep them from going extinct due to the flaws in interbreeding, they make it their business to kill monsters and launch invasions into the Demon Realm. They make no effort to spare the human "husbands" in the process, even if they were unwilling, to prevent them from spreading The Corruption, and some sects actually perpetuate the myth that monsters eat the humans that they kidnap so that people won't sympathize with them. On the other hand, it's mentioned that the clergy itself and most followers act more like a Saintly Church, and a special note is made that they aren't the great evil that monsters and monster sympathizers think they are.
 * Kuudere: Mantis. She acts like The Stoic her entire life, until she gets her first man during their Mating Season. After her first time, she'll be as dedicated to loving her husband as she is to hunting for food, though her affection outside of sex remains subtle.
 * Sahuagin counts too. She never shows any emotion and rarely speaks, but is loving and vocal during intercourse.
 * Kunoichi are as well, as a part of their Ninja-Education.
 * Little Miss Badass: Half of the Sabbath cult (the other half are their Lolicon husbands). To start, their leader is the Baphomet demon general, all girls - both monsters and humans - are converted into lolis upon joining the cult, with humans being given magic power and becoming witches. The settings information even notes that the cult is actually the magic caster unit of the Demon Lord's army.
 * Living Aphrodisiac: All Monsters are this to some degree. In fact, of the Monsters that don't attack men by themselves, you can be sure they'll manage to make you so horny you'll attack them.
 * Living Toy: The Living Doll.
 * Load Bearing Boss: The Demon Lord is one in a metaphysical sense. Should some hero manage to kill her, the old world design of the Chief God will come back in full swing. Meaning that all monsters will revert back to their former monstrous state, and start killing humans again - most likely starting with their beloved husbands. At a lesser degree, Lilims could also harbor this trope. Should any of them have enough power, she could become The Demon Lord's successor and can maintain the state of the world even if the Demon Lord were slain.
 * Love Freak: Lilim, just like their mother, want nothing more than to have humanity and monster girls coexist in harmony with love... expressed through sex. On the personal level, each Lilim is looking for one true lover to be her husband, despite having power to dominate as many men as she wants.
 * Love Is In The Air: The Alraune and many other monsters use pheromones to attract men.
 * Love Redeems, Love Makes You Evil : Demon Lord's husband is either of these, depending on who you're asking. He was made the most powerful human by the Chief God and tasked with killing the new Demon Lord, who had defied the Chief God by turning the monsters into monster girls and removing their desire to kill and eat humans. However, he sympathized with the new Demon Lord and they joined forces to make the world as it is now. They even fought the Chief God together when she (the current Chief God is female) appeared to slay them both for betraying her, won, and wounded the Chief so badly that she was forced to retreat and nurse her wounds.
 * Loveable Sex Maniac: The Merrows are the most lustful member of the Mermaid family and they never cease thinking about sex. However, when a Merrow proposes marriage to her husband-to-be, she gives him her hat. Said hat is the Merrow's Power Source and she can't even swim without it (unless she gets spirit energy from her husband). In other words, she puts her life in your hands when she asks for marriage. Furthermore, they are generally popular among other mamono, often trading away their lifespan-lengthening blood in exchange for dirty stories.
 * Another example is the March Hare. They are literally incapable of thinking about anything else than sex. No matter what men say to them, they will always interpret it as the man wanting to have sex with them.
 * Mad Hatter: There is a species mamono based on this character. And while it's not clear if she is aware of her own insanity, she is intelligent enough to appear to be sane.
 * Mad Scientist: The Sabbath didn't abandon their original purpose as magic R&D unit. Some of their inventions include a technique to engrave Pleasure Runes on clothes and yet still remain effective, a pill that turns a man into Naughty Tentacles and another pill that will multiply a man into a group of crazed rapists.
 * Magical Girl: Turns out to be a class of heroine in this world, as Fallen Maidens features a magical girl named Mimiru Miltie. Possibly a Shout Out to a certain magical girl series, her fallen state being a Witch, one that is much darker in appearence than the one present in the Witch profile.
 * Magic Is A Monster Magnet: Magic is derived from Spirit Energy -- the more spirit energy you have, the more powerful a magic-user that you are. Monster-girls essentially feed on spirit energy, and so are drawn to powerful sources of it. The consequences of this is that magic-users find themselves very desirable to monster-girls.
 * Magic Music: The Gandharva's music pacifies and arouses anyone who listens to it.
 * Mars Needs Women: Inverted. The monsters need human males to reproduce with to remain in existence.
 * Mating Dance: The Apsara's dance causes arousal into everybody who watches is. Either towards their own spouse or towards the Apsara herself.
 * Meganekko: The Blue-Oni sports a very nice pair of glasses, and they're also calmer and nicer than their red counterparts... as long as she's sober.
 * Meido: The Kikimora are this. Dressed like maids, they very dilligently do every household chore (and anything else) to make their husbands happy.
 * Mermaid Problem: Averted, for obvious reasons. If you look hard, each mermaid-type monster has lines that resemble thighs just below their waist, where the fish tail join with girl body, and, unlike many other mermaids, she is wearing something over it. The older art for mermaid doesn't address this problem though. The book's bonus art for the mermaid shows her genitals as well.
 * Among fans, the problem is alive and well with the Centaur and it's subraces. No one knows for sure which side of the body their genitals are on, they might even have two, one on their horse side and another on their human side.
 * Miko: The profession of the Shirohebi lamia-type MG. They are shrine maidens in the service of "Ryus", water-aligned dragon monsters that are treated as gods.
 * Mind Rape: Unusual for the normally "harmless" Monsters, the aptly named Mind Flayer consumes human minds and sometimes replaces a victim's mind with ones she likes more.
 * Moe Anthropomorphism: Enforced in-universe, and somewhat weaponized, by the Demon Lord’s power. Originally, most monsters were the usual gruesome run-of-the mill man-eating monstrosities you find in most RPGs. Their transformation into pretty girls was a vital part of the Demon Lord’s plan to merge monsters and humans into a single species and enforce peace.
 * Mon: The RPG is based on this concept. In other words, it's a harem building game.
 * Monster Lord: The Demon Lord.
 * Moral Myopia: Both the Demon Lord and the Order are convinced of their own righteousness and that the other side is a force of pure evil.
 * The Demon Lord's side is that the Order are a bunch of self-righteous puritans ruining her efforts to bring an end to a pointless war that the Gods created and forced upon both sides, as well as interfering with her efforts to gather enough power to improve the faults in her program, spreading blatant lies about her cause and murdering innocents who just happen to have found genuine love or simply sympathize with her cause.
 * The Order's side is that the Demon Lord has functionally destroyed two humanoid races, one of which (dwarves) was already on friendly terms with humanity (Dwarves have been almost entirely transformed into toddler-like girls, non-monster girl Elves are in great decline), is determined to rip human culture as it has always been apart, is threatening humanity with extinction due to the "monster girls only birth monster girls" fact, is cheapening love with her minions' abundance of mind-ensnaring magic and powerful natural aphrodisiacs, and her efforts to paint smilies on everyone's soul are basically an attack on free will itself even when they don't involve turning someone into a parody of their former self.
 * To some extent or other, both sides are right.
 * Mother Of A Thousand Young: Echidna are a mild case of this trope. Her first born is always another Echidna, but every child afterward is random, it could even be a whole new species.
 * Ms. Fanservice: All monsters are this to some extent or another. They prefer revealing clothes or going naked, will actively or involuntarily try to seduce and/or rape human men and some of them are fine with women as well.
 * Shameless Fanservice Girl: Monsters don't have many nudity taboos on what is considered tasteful clothing, some are aware of human taboos regarding this but aren't likely to care.
 * Innocent Fanservice Girl: Some childlike monsters like the Alice, emitting charm spells on people around them without being aware of it.
 * Mummy: Was there any doubt?
 * My Girl Is Not A Slut: Monster girls come in 4 types based on number of sexual partners: Type 1, those who surrender their virginity to their One True Pairing and remain monogamously faithful for the rest of their life; Type 2, those who have nothing but casual sex until they find their OTP and then they become just like Type 1; Type 3, those who have permanent harems of husbands, comprised of all the men they ever have sex with and they always keep on adding to it; and Type 4, those who keep wandering and have sex whenever they encounter a man. For Type 3, there are currently only Charbidis and Slime Queen, while Type 4 are mostly savage beasts with little intelligence such as Devil Bugs. Normally, Monster Girls almost NEVER engage in adultery, though some form a harem to single husband if they all love him.
 * That was in the very first edition. As of the second edition onwards, there are only Type 1 and Type 2, Type 3 has been modified such that those who prefer to be gangbanged will simply clone their husband into multiple bodies using magic instead of getting more than one husband, and Type 4 has been eliminated altogether so that ALL Monster Girls, no matter how apparently bestial or savage, will be capable of actually falling --- and staying --- in love with a man, who they will choose to be their one and only husband for the rest of their ageless existence. WordOfGod has expressly declared that the possibility of any adultery by a monstergirl with any male other than their spouse is absolutely zero, and any seemingly extra-marital sexual intercourse by the monstergirl with another female (who can only ever be a single bachelorette herself) never really counts as it is always just merely the means to the end of acquiring another sister-wife to add to the harem for the mutual satisfaction of both the monstergirl and her husband.
 * Naughty Nuns: The Dark Priestess is a Horny Devil whose whole shtick is that she preaches a "religion" proclaiming the holiness of regular sex and runs around in a fetishistic nun outfit. The Angel and Dark Angel kind of fit as well, given they are celestial beings who, particularly in the latter case, now live to have sex. There's also the Sea Bishop, a Mermaid-variant who has the fetishistic clerical uniform, but who is a loving, gentle and shy woman who performs the marriage ceremonies between humans and sea-dwelling monster-girls... which happen to involve the newlyweds having sex right there and then in front of the Sea Bishop (the act is combined with the sea bishop's magic to enable the man to live underwater), who secretly takes notes for when she finds herself a boyfriend...
 * The Roper specimen shown in the profile wears "ordinary" nun's clothing.
 * Naughty Tentacles:
 * The Scylla, being an octopus-based monster girl, has these-though they more often use their tentacles for binding their mates than for actual sex.
 * The Roper is (are?) this combined with The Virus. They bind and rape human men, use their semen to create seeds, and plant those seeds on a human female, causing her to transform into a another roper.
 * The Sabbath invented a "Tentacle Potion" which temporarily transforms men into near-mindless tentacle beasts. Often, they'll take these tentacles and use them as clothing until the effects wear off. The tentacle potion is also used to help a monster girl become pregnant faster or more easily as the tentacles produce a lot more sperm than the man normally can. Presumably this is useful because the monster girls bodies consume sperm and semen and thus getting enough inside them to actually have any left over to become pregnant with may be difficult.
 * Dark Matter does this as well, similar to the Roper.
 * The Demon Realm has a location known as the Forest of Tentacles. It is, predictably enough, a forest made out of Naughty Tentacles. Succubi and other monsters often bring their husbands to the outskirts to use them as marital aids, though they are wary of going deep into the forest where the trees are more aggressive. A human woman who wanders inside will be raped until she's either turned into a Roper by the forest or a Succubus by the Demon Realm's natural energy, and she'll probably want to come back as often as possible even after she's released.
 * And now there's a monster simply called "Tentacle" who are said to have been spawned from the aforementioned tentacle plants.
 * Some monsters can give humans this. The mates of Mindflayers and Atlach-Nachas gain the ability to transform into a squid and a giant spider respectively. The squid needs little explanation while the giant spider has a 'reproductive pouch' above their head that is a mass of wriggling tentacles.
 * Nightmare Fuel: Invoked; the Nightmare monster can invade people's dreams this way.
 * Ninja Maid: The Kunoichi are this to their husbands.
 * Not Hyperbole: Inverted, the author himself has said that, as opposed to what is written in some pages, monster girls do not desire sex 24/7 and do plenty of other things in their free time. They do, however, see sex as having an equal priority to eating.
 * Obake: Many entries, including Oni, Kappa, two kinds of fox-girls, Jorougumo and Yuki-onna. They are pretty much exclusive to a section of the world known as Zipangu.
 * One Gender Race: Every single monster race is all-female, although repeated sex with succubi family monsters (which includes vampires and dark angels) can turn a man into an incubus (which seems to just be a man with a monster-girl's lifespan and capacity for sex). In reality, all the monsters can do this, but those who feed off of spirit can do this much faster.
 * They weren't always either, but the current Demon Lord has put the world in its current state as part of her master plan.
 * One-Winged Angel: Dragons and their subspecies are so powerful that they can transform into their old monstrous form at will. Though it's said that none of them like doing it as it intimidates any present or future husband.
 * Oral Fixation Fixation: Ghouls. Full stop.
 * Our Monsters Are Different: Well, they're all female. And horny. All the time, in fact.
 * Some of the beast girl monsters have heat cycles and a few are better able to control themselves.
 * Well there's enough monsters that want to rape men to make sure men never leave the house. Unless you have a monster mate already, as it is stated most monsters will not attack a man who has been claimed by another monster (they can tell by sensing her energy and scent on the man).
 * All Trolls Are Different: They are gentle and intelligent in nature, look a lot like humans exept for the tail, pointy ears and large hands & feet as well as flowers growing on their bodies. They have a strong affinity with nature and can cause plants to grow in even hostile environments.
 * Our Angels Are Different: If an already-corrupted Angel has too much sex, she can fall and become a Dark Angel. Also found in other flavors like the Valkyrie, the Houri and the Cupid.
 * Our Centaurs Are Different: There are normal centaurs, but then there are also the Dream-Invading Nightmares, and the Virgin-Until-Marriage Unicorns. They're all incredibly lustful of course, though the vanilla-flavor ones at least try to restrain themselves unless they're drunk, and the Unicorns thrive on Virgin Power, both theirs and their husbands'.
 * Our Dwarves Are Actually Kinda Different For A Change: Dwarf females are toddler-sized little girls who're so good with their hands, the simplest touch makes men fall for them. The men are the same good ol' short, bearded, heavy drinking, jolly guys common in most RPG settings, though they're extremely rare now. When female dwarves began turning into succubi, most of them were very pleased about their brides becoming the kind of lustful woman they preferred to have while drinking after a day of work. Those who had wives that still hadn't become succubi actually wanted them to change, and sought to change their wives. Because of this the corruption spread like wildfire through the dwarven population. The male dwarves, and pure dwarves overall, are now on the precipice of extinction, with all new dwarves born female, beardless succubi.
 * Our Demons Are Different: They all want to bed you (if you're male) or convert you (if you're female). If you're lucky some may ignore you if you leave them be. Also, succubi make up the majority of the demon population now, so don't expect something like Diablo to pop up any time soon.
 * Our Dragons Are Different: Extremely intelligent creatures, but are slaves to their instincts, which have been warped. Their snobbish aloofness is an attempt to hide their forced attraction towards human men. They are now largely incapable of harming humans thanks to the influence of the Demon Lord. Like any other dragons, they love to collect troves of treasure, and once they find a man who they eventually grow to love, they treat him as the prize piece of their treasure haul. If at some point this man proves himself stronger than her (though this may simply occur in her mind as a result of her instincts recognizing him as a alpha dragon of sorts), she'll become an incredibly subservient "Lizard Woman," though only to her husband. Also, they're the only Monster Girl known to be able to resume their original, true monstrous forms, though only for a temporary period of time.
 * They also have a few subraces: the Ryu, Wyvern and Wurm. While they keep the Dragon's power, their appearance and behavior is completely different.
 * Our Elves Are Better: And this is what grants the Succubus-infected ones the Heroic Willpower to (temporarily) keep from mating with "inferior" humans. Even after becoming succubi they look down on and dislike other monster girls, paranoid that they will try to steal their men, and they still especially dislike dwarves.
 * Our Fairies Are Different: They're tiny, playful and very energetic girls that are normally born from special flowers and weren't originally monsters. Though monsterized Fairies do reproduce conventionally.
 * Also has two other subspecies: The Leanan Sidhe, who love and are fueled by great art, and the Titania, which are human sized and the queens of the numerous Fairiy Kindoms.
 * Our Ghosts Are Different: Being spirits fused with demonic energy, they are all perverts, no matter how they were in life. At first, they can't interact with the world physically and will possess humans. The victim will get his or her mind filled with obscene "Wild Ideas" from the ghost, while the ghost will get spirit energy by absorbing it from a male host until it's enough to manifest herself in physical world. By this time, a host will have been filled up with 'Wild Ideas' from the ghost, that she will get engage in sex directly immediately. In the case of a female host, she would likely be so overcome by the ghost's "Wild Ideas", that she'd become as much of a rapist as any Monster Girl, with the Ghost absorbing Spirit Energy through the possessed woman's victims until she had enough to materialize and do the deed herself.
 * Our Mermaids Are Different: Their blood can extend human lifespans, as in Japanese fables, though most apparently read lots of over-romantic stories about mermaids marrying human princes.
 * Our Orcs Are Different: They're chubby, pink-skinned women with pig ears on the top of the heads and literal pigtails (as in curly little stringy tails jutting from their rear), as well as being sadomasochists to whom, quite literally, Rape Is Love.
 * Our Vampires Are Different: Not as much as you'd think, strangely enough. The Vampires of the MGE are of the classic, regal, powerful, blood-drinking variety. They do feel pleasure from feeding, as does their prey, but they consider going as far as having sex with a human to be a disgusting act. However, the men they capture to act as servants and food sources will become Incubi if they're fed from enough, at which point the Vampire warms up to the idea of making one her husband. In some cases she may become a doting housewife around him. While there is no mention of holy symbols, they are weak against sunlight and garlic. Being exposed to sunlight makes them become weaker than the average female human, while the simple smell of garlic makes them drunk - actually eating it will make them go wild like other succubi.
 * Our Werewolves Are Different: They run around in packs and gang-rape any man they find. Unless you defeat the one trying to screw you, one way or another, at which point she'll become loyal to you.
 * Our Zombies Are Different: They feed on spirit energy - by having sex with men - instead of brains, and are all female but too dumb to distinguish between genders. Some may spend whole nights violating girls in futile attempts to get spirit energy. Those that are well-fed, however, may develop simple thought and seek out specific men.
 * Overly-Long Tongue: the Akaname. She uses it to lick dirt off of her husband.
 * Pandaing To The Audience: The Ren Xiongmao. Translated from Chinese, the name means Human Panda or Werepanda.
 * Parental Incest: Dark Elves hate humans, but still need male humans to reproduce, so when they do capture men they treat them as sex slaves to be dominated. They then teach their methods to their daughters who practice with their mother's slave... who is usually their father. The Devil Bugs, being Roachgirls, will also indiscriminately have sex with any male, including their fathers (and since they are such homebodies, this is usually what happens).
 * Person Of Mass Destruction: The Wurm, due to her near unlimited strength and stamina, can easily mow down an entire forest by herself when chasing a man.
 * Pettanko: The Harpy family (with the Gandharva being the exeption) are all very flat-chested, presumably because they're bird-girls and so need to be aerodynamic. The Cockatrice is a flightless subrace of the same family, but is a swift runner, so the same principal applies. The Werebat, Honeybee and Beelzebub, three non-Harpy fliers, are also fairly flat, while some water mamono, such as the Sahuagin, follow suit.
 * Goblin definitely counts if they aren't lolicon.
 * Petting Zoo People: As noted elsewhere, a fair number of the monsters are this.
 * Pity The Kidnapper: Whoever looks into the jar that a Jinn of the Jar's hiding in will get sucked inside and affected by charm magic. Since the very timid Jinn has no control over this ability, sometimes she will get raped by the man she pulled in.
 * Plant Person: Alraune, Liliraune, Dryad, Kesaran Pasaran, Tentacle, Matango, Barometz and Mandragora.
 * Playing With Fire: The Dragon can breathe fire, while the Ignis is a Fire Elemental. Salamanders possess flames on their tails produced by magical energy. They can be used as weapons or simply be harmless indicators of her arousal (both sexual and otherwise).
 * An interesting subversion with the Shirohebi. If her partner cheats on her, she'll actually solidify her raging jealousy into the form of burning blue flames, which she then forces into the body of her lover. Following this the man burns with sexual desire, unable to be satisfied by any other woman but her. The flames inside him never completely leave, so he has to keep returning to her. She becomes "the water he must soak in."
 * Plot With Porn: Though nothing beyond a couple of Light Novels has been produced yet, the large amount of background info given with each Compilation Book released hints at a much deeper story than just sex.
 * Pop Quiz: The Sphinx casts a curse on a man that comes across her, then asks him a question. If he answers her question wrong, the curse activates, making the man so horny he'll offer himself up to the sphinx. On the other hand if he answers correctly, the curse will be reflected back on the Sphinx... making her immediately rape him.
 * Prehensile Hair: The Kejourou; in fact, their hair is an important part in sex for them.
 * Proud Warrior Race Gal: Quite a few, most of them Amazon Brigades, including normal Centaurs, Lizardmen, Jinko, Salamanders, Hinezumi and, naturally, Amazons.
 * Pure Is Not Good: The Alice is the most innocent and naive of all the monster girls; she doesn't even understand what sex is (though if she has enough she does change to gain a partial understanding). She also broadcasts an aura that will eventually Mind Rape a man into a loli-lover, who will proceed to first rape the Alice and then become her Stalker With A Crush.
 * Questionable Consent: A big aspect of the setting:
 * The Yuki-Onna will use a blizzard to draw someone to their home. After treating him like a guest she'll proposition the man and if he refuses she'll cast a spell to chill his heart so that he longs for the warmth of human contact. If he still manages to resist and tries to leave she'll create a blizzard to try to force him back.
 * Gyoubu Tanuki will use Sexual Extortion to try to seduce someone.
 * Subtext suggests that undersea monsters have the ability to keep their mates alive while underwater for a certain amount of time. However, that also suggests that men caught by them could either submit to them or try to escape and risk drowning.
 * Rape Is Love: Several monsters, through creative use of pheromones or magic.
 * Orcs in Dere mode. In fact, they have an outright rape fetish, and are fine being the rapist (in Tsun mode) or rapee (in Dere mode).
 * Since all Monsters think Sex Equals Love no matter what, none of them would ever mind being raped by their current or future husband. But they don't seem to understand that humans don't have that same sentiment.
 * Rape Is Ok When It Is Female On Male: If you can't embrace this trope, the whole encyclopedia will be High Octane Nightmare Fuel.
 * Well aside from the few types that usually or never force themselves on men (Holstaur, Unicorn, Inari and such). The Demon Lord is also seeking to gain enough power to remove the instinct that causes so many monster girls to assault men (this presumably would not lead to an end of seducing men of course).
 * Reality Warper: Both The Demon Lord and Chief God can alter the setting of the world, although the Chief God simply struggle to keep the old setting rather than change anything.
 * Red Oni Blue Oni: One of the entries is a Red Oni, who is described as a super-strong party girl who likes to kick back, drink booze and have sex all day. The Blue-Oni is far more intellectual and composed than her Red Cousin...until she sees a guy she likes, then she drinks until she loses all her inhibitions, at which point she's just as bad, if not worse than the Red one.
 * The Red Sonja: The entire Lizard(wo)man race, along with their Salamander cousins.
 * Religion Of Evil: The Religion of the Fallen God, supported by Dark Angels, Dark Priests and Dark Valkyries. Not necessarily evil per se, but unlike most other Monster Girls that have a bit of restraint, the Fallen Lord's worshipers practice sex 100% of the time, especially in Pandemonium, the Fallen Lord's realm where Dark Angels and Priests bring their husbands. Time is frozen there, and there is nothing to do but have sex.
 * Refuge In Audacity: Although the mere premise of the Encyclopedia may be this, being raped by a sentient mushroom certainly is.
 * Rescue Romance: The Sea Bishop commonly gets a husband by saving a man on the verge of drowning. They do this by having sex with the man to infuse their bodies with magical power so they can live underwater.
 * Scary Scorpions: The Girtablilu is part of the "Arachne" family, and thus appears as the upper body of a human woman replacing the head on a giant scorpion. A skilled hunter, she's a sadist who compulsively stings a man she takes as her "husband" as a sign of affection. By sheer coincidence, this stinging comes faster and more frequent as she feels more turned on/falls deeper in love, her venom is a combination of paralyzer and aphrodisiac, and prolonged exposure to her venom eventually mutates her victim so that he actually derives as much pleasure from being stung as she derives from stinging him.
 * Serious Business: Surprisingly, despite the MGE being a sexual fantasy, a lot of people can debate quite intensely about the morality of the setting's Demon Lord and her plan.
 * Sex Equals Love: The entire essence of the Demon Lord's plan to bring world peace. Therefore it is part of the core instinct of all monsters.
 * Sex Slave: Surprisingly not very prevalent. There are, however, the Orcs, the Dark Elves and the Amazonesses. Orcs will challenge a man they like to One-On-One combat; whoever loses becomes the slave in the relationship. Dark Elves treat their husbands as slaves because of their natural pride. Amazons go out on raids to carry men off to their villages, where they will be forced to do all of the housework and mounted in public by their kidnapper whenever she feels horny.
 * The settings information does clarify though that monsters that refer to their man as a slave or as prey are essentially synomizing it with "husband" and a strong love can be seen in how they treat the man despite the term they use.
 * Sexual Extortion: The Gyoubu Tanuki uses this to get a mate.
 * Shy Blue Haired Girl: Nightmares are extremely shy, and have light blue-purple hair.
 * Shrinking Violet: The Doppelganger's true form is that of a shy and timid little girl.
 * Sinister Scythe: Both the Baphomet and the Nightmare are seen with rather elaborate scythes, while the Mantis has a scythe-Like blade attached to each of her wrists.
 * Single-Target Sexuality: No matter how lustful or promiscuous Monsters may be, once a Monster has imprinted upon a man as her husband, he becomes "the only male in the world that exists", so they'll no longer be interested in sex with anybody else.
 * Sirens Are Mermaids: Subversion. Mermaids do love to sing, and men who hear their songs will get charmed. However, there are also actual sirens, a bird-human hybrid just like in Classical Mythology, with similar magical songs. While mermaids just love singing, sirens sing with the intent to get husbands.
 * Stripperific: It's stated that most monsters prefer these kinds of clothes due to it helping to attract mates. Even when their 'clothes' are actually retractable fur or scales it still show a lot of skin and doesn't hide their figure.
 * Sleepwalking: The Dormouse are capable of walking around while fully conscious during their sleep.
 * Sleepyhead: The Dormouse are almost always sleeping, and when they don't they are always drowsy. However, they are capable of walking around and talking to people while they are asleep.
 * Snake People: The "Lamia family" of mamono.
 * Snakes Are Sexy: The premise of the Lamia, Echidna, Medusa and Shirohebi races.
 * Snow Means Love: Played Straight. There's a Yuki-Onna Monster Girl, but luckily she prefers to take in and mate with men she leads astray in snowstorms.
 * Spider People: Arachnes
 * Stalker With A Crush: The Lizardman entry says if someone defeats her she'll offer herself to be his wife and if the person refuses she'll most likely stalk him until he changes his mind. Given her appearance, this isn't necessarily a truly terrible thing...
 * Likewise the Dullahan which will out and out hunt the man she likes down to bringing him back to the demon realm... and she always finds her quarry.
 * Young Kappas will play with male children around their age, not simply because they enjoy human company, but because they're picking out husbands for the future. Yuki-onna do the same thing when they are young.
 * The lizardman's cousin race, the Salamander, does this in a more blatant way. She'll stalk the man she likes but is not quiet about it, taking every opportunity to shout to the world about how much she loves him and wants to be with him, as they tend to act without thinking things through first.
 * In fact all monster girls can become this to an extreme extent. That is once they come to recognize a man as their husband they gain the ability to sense his particular spirit energy and track him down no matter how far he may try to flee from her.
 * Stop Being Stereotypical: Due to the monster's predator instincts, most of them tend to be agressive in aquiring a mate, even if they have to drag him away kicking and screaming. This, of course, makes it very easy for the Order to potray them as evil beasts that eat their human "victims".
 * Super Drowning Skills: An interesting subversion with the Nereid. They'll drag women down under the waves and drown them...only for the victim to be reborn as a new nereid.
 * Super Not Drowning Skills: All the undersea monsters. Sea Bishop especially for being able to give husbands of such species the ability to breath underwater. The ritual, of course involves sex between the wedded couple.
 * Super Strength: Monster girls are stated to be physically stronger than average humans in general. Red & Blue Oni, Ogres, Goblins (Hobgoblins especially), Vampires, Minotauri & Wurms are all explicitly much stronger than any human.
 * Taken For Granite: Medusas use this technique to kidnap desirable men. The Cockatrice also has this power. Luckily, the effects are reversible. Also, Gargoyles turn to stone when the sun rises -- and if they're on top of a man when it happens, he does too.
 * Tanuki: The Gyoubu Danuki. Has large, bulbous pants, and is apparently a Proud Merchant Race. Described as a "Bad Girl".
 * Tenchi Solution: Monster Girls in the MGE are generally monogamous, but in some situations will form a harem for a single husband. He must be able to satisfy them all however.
 * The Slacker: Due to Monster's hedonistic nature, they tend to put hardly any effort in any job if it doesn't help them get laid, even if they are employed. Since this also applies to the soldiers in the Demon Lord's army, you have to wonder how it hasn't been defeated yet...
 * The Themepark Version: In-universe example. The Order's lore claims that "The wicked Demon Lord who emerged from the darkness is working from the shadows to destroy humanity". Fact is, the Demon Lord and the monsters were included in the design of the "World" that the Chief God created. See Jerkass Gods entry above for detail.
 * Three Way Sex: It's mostly 2 girls and a guy, though Sabbath's Doppelganger Medicine can create a girl and 2 guys scenario (although they would prefer many more guys in this case).
 * If it turns out that a Doppelganger's target's beloved woman did actually love him back, then when she sees the Doppelganger borrowing her form, they will be linked through demonic energy, causing the woman to slowly change and eventually become a monster like the Doppelganger. Then they will have sex with their beloved man together.
 * As lustful monsters, elves and dwarves often tend to take a liking to the same man, and it often leads to the usual Elves Versus Dwarves. Except that it won't develop into the kind of fight where they spill each other's blood. Instead, they both snuggle up against the same human man, pinching him between them.
 * In case of elementals, if the covenanter from when they were a pure elemental was a woman, the demonic elemental will also change her covenanter into a monster the same as herself. After the demonic elementals change them into succubi, succubi elementalists will use the elemental's power to assault human men, and they'll end up having threesomes all the time together with the elemental.
 * The Liliraune focuses exclusively on this. It's a variant of Alraune with two women inside the flower. If they find a husband, they sandwich him between them.
 * Too Dumb To Live: The Dwarves no longer exist as a full species because after liking the changes that happened to their women becoming Succubus they decided to do that to their whole species. Since Succubus can only give birth to females you can guess that it ended well.
 * Tomboy: Many Alps don't like their change and will continue to act like men. Although they won't mind having sex with men, eventually.
 * Tomboy And Girly Girl: Those who welcome their change, however, become even more feminine than actual women and get the bodies to match.
 * Trope Overdosed: As if this page wasn't obvious enough. Each monster embodies at least one trope, and there are plenty of monster girls.
 * Tsundere: Dullahans. Tsun with their head on, Dere with it off.
 * Orcs are Tsun or Dere depending on whether they or their lovers are dominant.
 * Vampires are Tsun, at least until their lovers become an incubi, whereupon they, sometimes, become Dere.
 * Dragons may also count, as all of their pride and self-dominance goes down the drain when they recognize their husband as a "stronger male", at least, when around said husband.
 * Background stories also mention that the Demon Lord is this. The fact that they're now parents to many, many daughters doesn't stop her from being often quite Tsun-ish towards her husband.
 * Thou Shalt Not Kill: A mandate imposed upon the monster races via the Demon Lord's power. Since the entire idea behind the monster girls is to achieve peaceful coexistence, no monster can willfully take a human's life. Ironically, it's the humans that have no such restrictions. Recently translated material has outright stated that monsters will still kill in self-defense and in order to protect their husbands (and presumably their children and friends).
 * There are, however, plenty of monster girl species who have been stated to violently brutalize men they catch, some with weaponry, some with their own eldritch bodies. Luckily, it's stated that, physically at least, the men are not harmed to any appreciable degree by even the more extreme behaviors. Demonic energy is stated to even automatically protect the man from the claws and horns of his mate during sex.
 * The Lamia however is pointed out as a patial exception, being jealous enough that they'll painfully squeeze him if he's been unfaithful to any degree until he confesses. No word if she does it even if he cannot help it.
 * Twin Threesome Fantasy: Doppelgangers might make it happen. Also pretty much the fetish the Liliraune caters to.
 * The Undead: The Zombie, Ghoul, Skeleton, Ghost, Will-o-the-Wisp, Wight, Doppelganger, Vampire and Mummy entries. Dragon's update profile from compilation book also mention Dragon Zombie.
 * Unicorn: They're Centaurs who stay virgins until they marry and only seek virginal husbands too. Not that this makes them less dirty-minded.
 * Unusual Euphemism: The Kunoichi's "Assassinations" consist of them sneaking into the home of their target, and seducing him with utmost ease.
 * Unwanted Harem: If a Goblin takes liking on you, the Goblins will bring you back to their village. And you will have to do it with all of them.
 * This applies to a lot of pack-oriented monsters, actually. Like the Werewolves or Orcs.
 * Valkyrie: They are warrior-angels serving the Chief God. Just like regular Angels, they have a corrupted version named "Dark Valkyrie" who, despite being followers of the Fallen God, are only loyal to their husbands.
 * Violently Protective Girlfriend: While it's said that Monsters hate killing or hurting anyone, they'll become very dangerous and ferocious if their loved ones are in danger. Especially noticable with the ferocious Hellhound, who's fury is described as "the sight of hell".
 * To give an idea, a small side story about the earlier days of the Demon Lord's rule talk about how a Succubus (implied to be the Demon Lord or one of her daughters) and her husband were attacked by dangerous tentacle plants. When the man was injured by them the Succubus vaporized all nearby plants and afterwards the army of the Demon Lord arrived and leveled almost the entire forest.
 * Virgin Power: The Unicorn toys with this. Her magical powers get weaker if she has sex, but only if her lover has had sex with monster-girls other than her.
 * There's also the even weirder/kinkier example of the Alice monster; her Virgin Power drives men to rape her. And when they're done she gets Easy Amnesia and becomes a virgin again.
 * The Virus: Many monsters, most notably the Succubus, and always targeting females. Others include the Werewolf, Matango, Roper, and Dark Slime. Possibly the Honey Bee as well, though it's not revealed what happens to the women they kidnap.
 * The Matango has a rare ability to change men; if enough of her spores get inhaled, he turns into a "mushroom person" under the hive-mind's control.
 * If a woman puts on a Mad Hatter's hat, they will become one themselves.
 * And with the introduction of the Lilim, a woman can now be transformed into almost any monster (though the some monsters need specific conditions to be met). Men also become Incubi when coupled with monsters for long enough, and though they technically aren't monsters themselves, they behave the same and can act as The Virus to human women on behalf of whatever monster species changed them.
 * Definitely the aptly named Parasite Slime. They're a unique variant of Slime that, instead of taking on human form themselves, enter the body of a human woman, fuse with her, mutate her body and change her personality. If the fusion is complete, they'll become known as a "Slime Carrier".
 * Voluntary Shapeshifting: Many monsters can disguise themselves as human women. The six Dragon variants are standouts, being the only monster girls known that can transform into their original monstrous forms. Nekomata can disguise themselves as ordinary cats. The Doppelgangers take on the form and personality of their husband's ideal woman.
 * On the men's side, Wendigo's, Mindflayers and Atlach-Nacha's give their mates the ability to turn into an ape-like creature, a squid and a giant spider respectively. Those men can voluntarily change back but their wives prefer for them to be in their transformed form. They are comfortable with having sex in public when their men are in the transformed form but not in regular form.
 * Weaksauce Weakness: Some mamono have this.
 * The Mimics and Jinns of the Jar become powerless if they are ejected from, respectively, their chests or jars. With the Mimic you just have to shove a key in the keyhole of the chest, and with the Jinn you just have to throw something in their jar or just break it.
 * The Werebat is terrified of lights, and will therefore become helpless if exposed to bright lights.
 * The Hinezumi becomes calm and timid if her flames are extinguished with water.
 * Giant Slugs become smaller and helpless if salt is poured on them.
 * If the dish on top of a Kappa's head dries up, they will lose their strength.
 * Vampire's become powerless when exposed to sunlight.
 * Well Intentioned Extremist: The current Demon Lord, a succubus, had decided to try to fix the ages-long mutually genocidal war between mankind and the monster races. Unfortunately, her method of doing so has caused the world to sink into its current state. While some welcome the change, those that don't aren't given a choice in the matter.
 * Differently so, the current chief celestial power recognizes that she (The Demon Lord) hasn't left the world in the best state. Unfortunately her method of dealing with the problem seems to involve forbidding humanity to make contact with monster kind, and resorting to genocide when necessary. The Chief God actually controlled the previous Demon Lord, using his control over the Monsters in order to prevent the overpopulation and self-destruction of humanity, and thus is the reason for man and monster's old eternal war.
 * When Trees Attack: Dryads, Alraune and Liliraune are like this... just replace Attack with Rape.
 * White Haired Pretty Girl: The Lilim, Dark Angel, Dark Priest, Dark Elf, Shirohebi, Ogre, Yuki-Onna, Yeti, Unicorn, Ghost, Zombie, Skeleton, Holstaur, Arachne, Cockatrice and Ren Xiongmao all have very light hair, varying from white to various color-shades of silver. And while we never see her, the Demon Lord is probably also an example, as Lilim apparently strongly resemble their mother.
 * World of Buxom: With the exception of child-like monsters and harpies, all monsters are well-endowed with C-cup breasts being small among them.
 * Wu Tai: The Zipangu region, which is the home of all monsters based on Japanese mythology, as well as humans who fashion themselves after Jidai Geki. The monsters are even referred to as "Youkai" there, as opposed to just "Monsters". They range from being tolerated, to welcomed, to even revered by the humans who live there - and vice versa. They seem to be the third option of the Black and Gray Morality of the setting, but sadly don't seem too interested in the struggle between the Order and the Demon Lord. Rather they have built up their own forces to keep the other powers from interfering in their part of the world. Further information has also shown that while they do not actively serve the demon lord they are not against her as it is thanks to her that they have become able to live even closer with humans than they could before.
 * Yamato Nadeshiko: Nureonago, Yuki-Onna (who even wears a kimono), Shirohebi & Kikimora.
 * You're Drinking Breast Milk: The Holstaur's breast milk is said to be "both delicious and nutritious" and apparently sells well among both humans and monsters.
 * You Gotta Have Blue Hair: Mermaid, Succubus, Sea Slime, Beelzebub, Pixie, Jinn of the Jar, Medusa, Sea Bishop and Nereid.
 * Yandere: The Will-o-the-Wisp. While some monsters involuntary trap a man (like a Jinn of the Jar), the Will-o-the-Wisp actually imprisons her husband in her cage to the point that not even their soul can escape after death. They're also very jealous and cannot stand it if another couple's happier than her.
 * Lamia count as well. If their husband is unfaithful to any degree, they'll painfully strangle him until he confesses. In the older version, it was said they actually killed him that way.
 * Youkai: The monster girls of the Zipangu region. They've peacefully coexisted with humankind since long before anyone can remember. Unlike the rest of the monsters, youkai aren't part of the Demon Lord's Army, and, since Zipangu isn't under the influence of The Order, there are no Knight Templar hunting them down (though invasions from anti-monster kingdoms have been attempted and failed, and some more ferocious youkai are sometimes hunted). In fact, powerful youkai like nine-tailed Inari are often revered as gods.