Homunculi

The homunculi (??? ???) are a non-native collection of extraterrestrial species introduced to the One Piece world via the powers of the Planet Planet Fruit as used by the legendary Creator, Vulcan. Due to their inherent nature as aliens, a homunculus can possess any sort of natural ability or talent that is naturally found on their planet of origin; usually depending on the object or organism Vulcan designed the planet from. These alien-like beings can range from average looking humans, animals and plants to much more bizarre creatures, including sentient minerals, beings capable of natural metamorphosis, beings made of fire, creatures considered long extinct such as dinosaurs and mammoths, or even more unfathomable beasts. Vulcan has shown that he can even create massive versions of scientifically recorded life like bacteria, amoebas and viruses, or recreate creatures from legend and myth, such as dragons.

These beings normally populate Vulcan's home island in the Calm Belt, safely kept away from the public at large for their protection while also lovingly cared for by Vulcan himself as his "children." Every so often however, a customer may approach Vulcan to request a homunculus of their own, for any number of possible reasons. Likewise, some homunculi have decided to leave the island of their own free will to go and travel the world for an equal number of various reasons.

Currently, the starting slave price for any homunculus is a hefty 1,000,000, most likely due to the rarity of their species in comparison to other races and species in the One Piece world; making the homunculi a highly sought after decoration due to their bizarre or attractive appearances, or a valuable form of labor due to their unusual abilities.

Appearance
In terms of looks, the homunculi are as varied and unique as they come. Due to the near-infinite different planets Vulcan can produce alone or combined, and thanks to his full control over how evolution functions on each planet he makes, Vulcan can produce nearly any kind of homunculus when it comes to appearance. If so desired, no two homunculi can look the same, or inversely, exact copies can be spawned at will. For the most part however, many of the homunculi seem either monstrous in design or can appear as typical humans, plants and animals seen in the One Piece world. Likewise, some homunculi can mimic the appearances of giants, fishmen and merfolk, minks, bigfeet, skypieans, hellpieans, and more and more. Some can even take on the likeness of extinct species such as dinosaurs, or mythical creatures like phoenixes, dragons, ghosts and so on. Others may have more bizarre appearances, such as taking on the appearance of mountains and trees, or elemental forces of nature like fire and water.

Whether due to accidents or design, some homunculi can later have their appearances modified through technology or Devil Fruits possessed by others. Usually this will result in cyborg homunculi when technology is applied, and either more tame or far more eldritch beings when affected by Devil Fruit powers such as Zoan Devil Fruits. It should be carefully noted however that after a species of homunculi has been bred on its home planet and later summoned to this plane of reality, the homunculus' appearance can no longer be altered outside the use of physical force, cyborg attachments, and Devil Fruit alterations.

Shades
Among the homunculi sub-classes, shades tend to stick out more than others, mostly due to their ghostly or demonic appearances and their innate powers. In general, shades can be identified by their tendency to appear in darker colors such as black and gray, as well as possessing characteristics that may seem abnormal or inhuman, such as pointed ears, horns, wispy and ghost-like bodies, and other such strange features; albeit shades sporting colors such as whites, oranges and so forth is not unheard of either, and neither is it odd if a shade appears more "average" than usual. Typically, it is simply common for shades to look the part of a spirit in some way, shape or form, but certain shades may appear more mundane from time to time, depending on certain circumstances.

Ability-wise, shades all share the same underlying property within their bodies: Magnetically charged blood. Like humans and other living beings, shades have iron blood flowing through their veins which keeps their heart and muscles active, allowing shades to live. Unlike humans and others however, shades seem to have a unique characteristic within their blood that allows it to magnetize and channel electric current through the body without harming the shade in question, thus giving a shade's entire body a magnetic charge and allowing it to more easily interact with magnetic fields and electricity. While normally a passive ability from birth till death, the shades can train themselves to harness their magnetism in a similar manner to Life Return, thus letting them manipulate, control, alter and affect various metals and other magnetically sensitive items and equipment at will. Even when untrained and inexperienced, shades can still tap into their magnetic powers by way of acting like a living compass. This then makes them highly valuable shipmates while out at sea, as they can easily navigate the world's oceans, up to including the Grand Line as well. However, this also makes shades very sensitive to the various magnetic fields of the Grand Line and Red Line, meaning shades can have their behavior or moods affected by an island's magnetic field depending on the individual shade and the type of island or segment of the Red Line. This can be clearly proven by Poe's statement regarding his enjoyment of Sheol's magnetic field, or Ghashley making remarks regarding various islands and how they "feel" to her.

Aside from being relied on for navigation, a shade's magnetic abilities can be exploited even further through the usage of magnetic attraction and repulsion. A common tactic many, if not all shades use is that of levitation, mainly done by charging themselves with the same polarity as that of the surface underneath them, causing shades to be pushed upward into the air and either float, or in more extreme cases, fly. Likewise, in the same manner as that of infamous pirate, Eustass Kid, shades can pull magnetically sensitive items such as metals towards them or push them away from their being. This among other abilities can be the source as to why shades can be confused for Devil Fruit users.

Also is the fact that through further training and applied usage of their magnetic blood, a shade can summon electric energy from within their bodies, manipulate it through magnetism and release it outward however they wish. So far, Poe of G-4 has shown the most use and greatest talent for this ability, as he has created various methods of channeling electricity for offensive and pragmatic means; one such method is his "will-o-wisps," which are balls of electricity he can fling from his hands or fingers at will. He has also shown the ability to cover himself in a shroud of electricity for defensive purposes as well as firing bolts from his palms. Likewise, Poe has shown that truly disciplined shades can control magnetic fields to such an extent that one can even alter the electric signals within the brain, both for themselves and for others, thus allowing Poe and other such well trained shades to sabotage another person's senses, ability to think and reason, and even alter their perception and sense of reality, causing them to enter almost realistic hallucinations and trances. In some respect, this ability to rework the minds of others can be regarded as superior to the illusions generated by the Majin tribe, as the effects of a shade's neural manipulation works directly on the brain as opposed to the Majin's manipulation of the body's senses. Therefore, it's implied very powerful shades can cause others to enter blissful dream-like realities or even living nightmares at their whim, all the while also elevating their reputation as "real ghosts" to those less knowledgeable of their abilities and backgrounds, due to tricking others into "sensing" the shade as having spiritual physical traits or powers, such as creating a sensation of coldness in the immediate area.

In relation to other homunculi and non-homunculi races and beings, shades typically tend to run the gamut in terms of interracial relations. Where some shades may be hated, feared and rejected as monsters and freaks by the outside world, others may just as well be welcomed, loved and respected for who they are. Likewise, some shades may feel tolerant of non-shades and may even be polite and friendly to them, while other shades may come off as racist, shy, fearful, or act superior to non-shades. The vast range of their reactions towards others usually means the unique personality of a shade will determine how they get along with other people, much like it is with humans. When it comes to breeding, shades seem capable of mating with humans, hominid and shifter type homunculi, and human-like races such as the fishmen, merfolk and bigfeet; even being shown capable of conceiving and giving birth to shade crossbreeds.

However, despite being capable of breeding with others, shade blood is incompatible with non-shades, as the unique properties of a shade's bloodstream may cause unintentional side effects within others, or may even lead to death through poisoning or electrocution. Likewise, while shades are physically capable of receiving blood donations from non-shades, this will only help in diluting their magnetically charged blood with non-magnetic blood, which in turn can hamper, and in long term cases, completely shut down a shade's ability to interact with and manipulate magnetic fields and electricity. Therefore, while they can receive blood from those outside their race, it is usually best for a shade to refrain from sharing blood in the slightest with non-shades. Likewise, while shade crossbreeds can be possible, the end result may cause the hybrid child's bloodstream to be too mixed to be as effective as a pure-blood shade, which can result in weaker or totally ineffective magnetic powers from the child.

Other features of a shade's biology seem to suggest they can survive on the same diet as a human and that they may require other key necessities humans would need to survive, such as toilets, tubs and showers, medicine, shelter and proper hygiene equipment such as toothbrushes and soap.

Beliefs
As a result of being produced by Vulcan on his numerous planets, those with sentience and cultures that have developed faiths and religion have come to see Vulcan as a literal god when living on their home planet. This is because on a normal day to day basis, a staggering number of homunculi cannot see Vulcan but feel they can sense his presence in their lives; often reflecting our own real world's various faiths involving creator gods who cannot be sensed by normal means but can still be felt in a spiritual level. Therefore, homunculi and Vulcan share a very similar relationship to that of real world gods and their followers, although this can only be said of homunculi that exist on their respective planets. However, despite this worldview, not all homunculi may share such a sentiment. Indeed, some homunculi may be atheist or agnostic and question Vulcan's existence entirely.

For those who have been summoned from their planets, they may be shocked to meet their "god" face to face, should they believe in such a thing. Upon doing so, each individual's experience is up to who they are and what their species and culture dictates; with some homunculi venerating Vulcan as a literal deity, to some seeing him as genuine creator and father figure to respect, treat kindly and love, to treating him as an equal life form and choosing to live in co-existence with Vulcan, to outright denial of his creator status and choosing more skeptical, even outright rebellious attitudes. Essentially, it all comes down to the respective homunculus as to how they perceive Vulcan and respond to meeting him and entering "his" world. Vulcan himself states that when his homunculi worship him, he can feel their prayers, thoughts, sacrifices and adherence towards him as paternal love towards his "children."

Aside from that, the beliefs of a homunculus are as varied as the race itself; with some practicing barbaric rituals to others acting and thinking in a more civilized manner, as well as everything in between. In short, no one knows how a certain homunculus will behave or what they choose to believe until they're met.

Trivia

 * The homunculi received their name due to the word meaning "little human" in Latin. Both Vulcan and Wyvern 0m3g4 chose this name because of the near-atomic size the homunculi normally possess while living on their home planet; usually being too small to be seen with the naked eye.
 * Wyvern had also chosen the name to play up Vulcan's alchemist motif, as homunculi typically are associated with alchemy.