Arachne

The Arachne (アラクネ族, Arakune-zoku) are a carnivorous, mono-gendered demi-human liminal race that have a human torso but are attached at the hips to the body of a giant spider. They are physically strong and fast.

Arachne are most noted for being able to create a silk that is five times stronger than steel and twice as elastic as nylon. They can also produce variants of the silk, ranging from sticky, to stretchy, to tough, to suit whatever situation is required. While most commonly used to catch and bind prey, Arachne can also use their silk to form a network of threads to sense vibrations.

Culture
Known for creating "community nests" within dark forests and deep caves and caverns, the Arachne are reputed for being deadly towards humans, famed for using their webs for entrapping men and women and killing them through either eating them whole or biting into their skin and sucking out their bodily juices like a spider. This reputation arose due to the Arachne's natural predatory abilities and form and due to their behaviour of, being a female-only race, luring men to their hidden dwellings and holding them for mating in order to survive as a species; using their webs to restrain the men should they resist. As stories of groups of men being captured by Arachne are rare, it is presumed that on average multiple Arachne would have to mate with a single male, although it is unknown whether they do so in groups (orgies/threesomes/etc like the Lamia) or individually (with the man being shared/passed from one Arachne to another each night)(Rachnera Arachnera's open bisexual tendencies during sexual play may allude to the former being true). Additionally it is unknown whether the Arachne that captured the male has first rights to mating with/owning them or if men are caught to be shared by the nest (like fishermen catching fish for the village to eat).

Since the Cultural Exchange Between Species Bill, government agencies have put a stop to the Arachne practice of luring and kidnapping men against their will (due to being a federal offense). While this fortunately put an end to the mass abductions (and borderline sexual assault) of human men, the results were not so positive for the Arachne, who need men to maintain their numbers and produce the next generation. Presumably, the Arachne birth rate has declined dramatically due to this. In an attempt to evolve their culture to become "more open", Arachne nests have taken to sending "expeditionary forces" via the exchange program for the purpose of ascertaining whether or not Arachne and Humans can coexist despite the Arachne's intimidating appearance and Humanity's tendency to vilify anything different from themselves.

The Arachne's traditional craft is knitting, which they have honed after repurposing their abilities from typical "web spinning".

Physiological Attributes

 * The average Arachne has six eyes but the number can vary between individuals.
 * Arachne bodies are covered by a hard, though light, exoskeleton. They possess sharp claws on the ends of their fingers which are used to cut open prey, and as such can easily cut human skin.
 * Arachne have two sets of lungs; a set of lungs in their human torso that are like a human's (inflates and deflates to draw oxygen into the blood cells, as well as separate carbon dioxide), and a set of lungs in their spider abdomen called "Book Lungs", that all arachnids have, that absorb oxygen into the body from the environment without the Arachne needing to "breath" in or out.
 * While typical spiders use their pedipalp legs (the two front-most legs) for eating like typical human hands, it is assumed that, due to their small size and position, Arachne use their pedipalp legs to hold the lower half of their prey while feeding and it is believe that they are also used to hold their mate in place during intercourse as, due to the Arachne's vagina being located between their pedipalp legs, the legs could easily assist in vaginal penetration.
 * Each Arachne is born with a unique pattern on their opisthosoma (spider abdomen).However, the patterns of Arachne, which are members of the same tribe, seem to have similar patterns, even if with some individual differences, as in the case of Rachnera's tribe.
 * Like spiders, Arachne can get drunk from ingesting caffeine.
 * While possessing a primary spinneret at the rear of their opisthosoma (spider abdomen), from which they are able to produce and emit silk like a typical spider, Arachne also possess spinnerets in their wrists which can emit silk in a similar manner. It is unknown whether the different spinnerets can emit different types of silk, at different lengths, thicknesses and strengths, or if they possess the same capabilities and the arachne simply opts to use whichever spinneret is convenient.
 * Arachne silk is a rare and valuable commodity. While it has been shown that Arachne can produce and gather enough of their silk themselves to sell, it has been demonstrated that Arachne can also have their silk "milked" directly from their spinneret by machine. The process of having their silk milked out of their spinneret is demonstrably pleasurable and arousing for the Arachne. This supports the notion that an arachne's rear spinneret is a sensitive erogenous zone that some may enjoy having fingered, touched, manipulated orally, teased and/or penetrated during intercourse.
 * All Arachne females are proficient in bondage, as it has uses in mating. It should be noted that Rachnera Arachnera is exceptional at this practice.
 * Although they typically wear a loincloth curtain to offer modesty and bikini styles do exist to offer effective "coverage", Arachne do not effectively wear underwear to cover their genitalia (although they do wear bras to secure their breasts). Whether this is a cultural aesthetic or a personal choice is unclear.
 * As their silk is mainly composed of protein, Arachne require a protein-rich diet to maintain their silk production.

Small Breeds
The Small Breeds (小型種, Kogata-shu) subspecies is smaller in size than the standard Arachne. Their legs are short, but they can move much faster than standard arachne, and they are good at jumping and full of energy.

Instead of spinning webs, these Arachne wander around on the ground in search of prey. They can produce thread, but they only use it to stop their descent when they fall from high places.

Long Leg Breeds
The Long Leg Breeds (アシダカ種, Ashidaka-shu) are a large subspecies with thinner and longer legs than standard Arachne. These large Arachne are mild-mannered. They cannot produce thread, but they move surprisingly quickly to secure their prey. Their hunting instincts are so powerful that they will sometimes abandon the prey they have captured to pursue new prey.

As they are especially uncompromising regarding the extermination of household pests, they are respectfully known among those troubled by such pests as “sergeants”.

Large Breeds
The Large Breeds (大型種, Ōgata-shu) subspecies is far larger than standard Arachne with thick legs and a covering of hair. They are very wild and aggressive. In addition to being strong, they also have venom, making them extremely dangerous to approach without caution. That being said however, said venom is not particularly strong nor harmful.

They are not well-suited to interspecies exchange programs, as when they have interacted with humans, they were arrested for assaulting them and causing other problems.

Members

 * Rachnera Arachnera

Trivia

 * The Long Legs subspecies is the only Arachne who uses katakana for their subspecies name.
 * Arachne weave a durable cloth from their own threads, the main component of which is protein. Its beauty and rarity command a high price on the open market due to its strength, but its true purpose is to merely catch and prevent anyone ensnared in it from breaking free.
 * Since spiders are related to scorpions, it can be assumed that Arachne are also related to Serkets and Scorpions.
 * Because of their superior abilities, Arachnes are one of the most powerful and dangerous extra-species in the world.
 * One of the Eight Brothers is dating an Arachne girl. She is concerned about accidentally hurting her boyfriend due to her claws and considers herself a monster that he should stay away from because of this.
 * The Long Legs subspecies' appearance and nickname of “Sergeant” is a reference to 2chan, which refer to huntsman spiders as “Sergeant Ashidaka” due to a particular thread discussing “anti-cockroach forces”.
 * It is unknown whether Arachne are protostomes or deuterostomes.
 * The appearance of the Large Breed Arachne may be based on the . Her prominent buttocks in the image may also be reference to the monkey on which the spider is named after.
 * Although the species of the Arachne debuted in Volume 3, more details about their culture were only revealed in Volume 16, including the fact that they, like the Lamia and Harpies are a purely female species.
 * With regard to the subspecies of the Large Breed Arachne, this can prove problematic as they are not well-suited to the interspecies exchange program, but require human males to maintain their species.
 * In Monster Musume I heart Monster Girls Volume 1 Rachnera makes it clear that despite their spider-like biology, Arachne don' t eat insects. However, this statement could be at least partially wrong, as Long Leg Breed Arachne are known to exterminate household pests. Possibly only standard Arachne don' t eat insects, but at least some of their subspecies do.
 * With regard to the Large Breed Arachne, due to their aggressiveness, this could mean that they also eat insect-like Liminal races such as Honey Bees, especially since they are known for attacking humans (which could possibly be one of the other problems that Large Breed Arachne caused.)