The Fundament is what was molded into the Material Plane. It existed before most alongside the Primordial Beings. There are still remnants of the Fundament found in the under dark.
The crustaceans humanoids from the Fundament
“My people are no more, and I grieve for it. Yes, I betrayed my king and would have seen his heirs eaten—but behold what became of them instead. Now the Osmium Court and Helium Drinkers, and every other nation of my kin, all alike are dead or worse than dead.” —Taox, Neuter Mother, Former Royal Tutor of the Osmium Court
Before they communed with the worm gods and became the Hive, the krill people were one of many species inhabiting the varied environments on a faraway gas giant remembered only as Fundament. Short-lived and fast-breeding, they believed themselves the weakest things in their world, prey to every predator and victims of their planet’s many vicissitudes. That changed when the daughters of the Osmium King returned from the deepest part of Fundament, bringing larval worms and forced conversion to their crusade of vengeance. All who refused the worm were put to death, and there is little reason to believe any of the krill people survived...
SHAPED TO SURVIVE
The krill people are humanoid bipeds with chitinous exoskeletons and somewhat crustacean physiology. They have four-digit hands, three eyes, and cranial crests that develop different shapes according to the morphology they adopt in adulthood. Their chitin may be different colors depending on dietary intake and individual variation. They exhibit flexible sexual dimorphism: one sex can undergo a naturally occurring transition to the other under certain conditions, as when a female undertakes the king morph.
Which morphological metamorphosis a krill undergoes, if any, can radically change their appearance and physiology in other ways as well. Those who assume the knight morph develop much more massive bodies with thicker chitin and greater strength. Those who take the mother morph not only gain the ability to lay eggs, but also hovering flight, as well as a much longer lifespan.
SORROWS FROM THE DEEP
The timid krill people lived among numerous species on Fundament, dwelling on floating islands of solid material that drifted upon one of the planet’s many layers of sea-like atmosphere. Their transformation into the Hive began when Sathona, one of the daughters of the Osmium King, followed the mysterious urgings of her father’s familiar, a strange dead worm that had washed up from the deep. The whispers of the worm led Sathona and her two sisters to the deepest part of Fundament, where the worm gods Yul, Ur, Eir, Xol, and Akka had been trapped for millions of years. They offered a bargain to the sisters: make their bodies symbiotic hosts to the worm gods’ larvae, and they would gain immortality and the power to avenge their usurped, assassinated father and escape Fundament, overcoming everything that had preyed upon their kind.
The sisters agreed, and accomplished all this in the first acts that transformed them and the krill people into the Hive. They brought the worms to every group of krill on Fundament, conscripting into their armies those who would accept the larvae, and slaughtering those who would not. No krill are known to have survived or escaped, with the sole exception of Taox, former adviser to the Osmium King, who orchestrated his overthrow. She fled Fundament and its moons, seeking to carry warning of the Hive to whoever might listen. In pursuit of Taox, the Hive advanced into deep space, obliterating one species after the next as their crusade of devastation grew mightier and mightier.
The Hive also chased after the Traveler, which the worm gods claimed was responsible for bringing the krill people to Fundament to suffer as miserable prey. In time, the Traveler attracted the Hive to Earth, where they have been a blight on the system and possibly the greatest threat to what remains of humanity.
THE TIMID TRUTH
Before their conversion into the Hive, the krill people accepted a precept they called the Timid Truth: that the krill were the weakest, smallest creatures that lived, and thus were naturally preyed upon by everything in the universe. They lived short, fearful lives, struggling to avoid being eaten by the predatory creatures of Fundament, as well as suffering attacks from other, stronger groups of krill. Despite this, they had science and engineering enough to understand some of the physical workings of their world, and built ships to sail the seas and even large engines to move their floating island continents.
KRILL TRAITS
Krill people of every morph share the following characteristics.
Age. Krill lifespan was about ten years. Individuals reached maturity at around two years old, and would choose which morph to assume, if any, by middle age.
Size. Typical krill were around 5–6 feet tall, though different morphs might grow larger. Your size is Medium.
Speed. Krill people’s springy limbs allow for fairly nimble movement. Your base walking speed is 30 feet.
Languages. You can speak, read, and write krill and common.
Darkvision. The krill’s three eyes were adapted for the murky conditions of living inside a gas giant, and see well in low-light conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light.
Wary Hypnogogia. Constantly threatened by predators, krill cannot afford unconscious rest. Instead, you enter a shallow trance, remaining semiconscious for 4 hours a day. While in this restful trance, you sometimes experience fleeting dreamlike episodes. Such dreams are the result of your subconscious manifesting itself, similar to the dreams a human may have. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep.
Morphology. You start as the acolyte morph. Whenever you increase in level, so long as you meet the level requirement of a different morph, you can choose to alter yourself to adopt it. This change is permanent and cannot be reversed. If you choose to do this, you lose the traits of the acolyte morph and gain the traits of the new morph you chose.
ACOLYTE MORPH
The natural form of adult krill is versatile but not particularly strong.
Ability Score Increase. One ability score of your choice increases by 1. When you adopt a new morph, this score is reduced by 1.
Instead of choosing a new morph, you can choose to make the acolyte morph your permanent form, which you can do at any time. If you make the acolyte morph permanent, you can choose one ability score to increase by 2.
Cunning Movement. Moving through an opening one size smaller than you does not count as difficult terrain for you. You can take the Disengage action as a bonus action on your turn.
Keen Eye. If you make a ranged attack roll and miss, you can choose to re-roll your attack roll once. You must use the new roll, and you must complete a short or long rest before you can use this trait again.
KNIGHT MORPH
Krill who undertake the knight morph become larger, stronger, and much better armored. They are the most formidable fighters among their kind.
Level Requirements. You can choose the knight morph beginning when you reach 2nd level.
Ability Score Increase. Choose either your Strength, Constitution, or Charisma score to increase by 2. You can increase one other ability score by 1.
Chitinous Plating. You have natural chitinous armor. You have disadvantage on Dexterity (Stealth) checks. While unarmored, your AC is equal to 14 + your Constitution modifier. Even while wearing armor, you can use this natural armor to determine your AC if the armor you are wearing would leave you with a lower AC. You are still subject to the effects of the armor you are wearing if you do this.
Fortified. If a creature scores a critical hit against you, you can cause the critical hit to become a normal hit instead. Once you use this trait, you must complete a long rest before you can use it again.
Heavyweight. You count as one size larger when determining your weight limit, as well as against effects that target Medium or smaller creatures and for determining what you can grapple, shove, or ride as a mount.
MOTHER MORPH
Krill eat a special jelly to catalyze metamorphosis into mothers. Their build becomes slender and capable of flying, making them evasive and nimble—traits useful for protecting their eggs.
Level Requirements. You can choose the mother morph beginning when you reach 4th level.
Ability Score Increase. Choose either your Dexterity, Wisdom, or Intelligence score to increase by 2. You can increase one other ability score by 1.
Evasive Flight. Your ability to move freely while airborne grants you the effects of a natural armor equal to 12 + your Dexterity modifier. You can use this in place of your normal armor while airborne, if this would grant you a higher AC. You are still subject to the effects of the armor you are wearing when you do this.
Flight. You have a flying speed of 30 feet in addition to your base walking speed, and you can hover in place while flying. You cannot begin flying if you are carrying a weight that is greater than half your weight limit, and if you are flying when you acquire this weight, you begin to fall. If you are incapacitated while airborne, you begin to fall.
Paperweight. You count as one size smaller when determining your weight limit, and for determining what you can grapple, shove, or ride as a mount.
These are humanoids spawned from creatures within the fundament. They all reflect their abilities through these fundament features and shadows.
Other humanoids that have been exposed to the fundament will take on the traits of Abyitir.
These creatures have a wide variety on physical traits that reflect abilities loosely. The abyitir also are creatures who thrive on suspicion and doubt, what creates the shadows of life. They have cool and dark skin that helps them hide in the dark waters of the fundament.
Abyitir need 12 hours for a long rest
Have a walking speed of 30 ft.
Can speak common, abyssal, and krill
Abyitir gain 3 to any one ability score
Their size trends on the larger size of medium creatures standing over most humans and elves.
Abyitir are weak to radiant damage and resistant to necrotic damage.
The Abyitir have on unique physical trait and their shadow trait
Physical Traits.
Nessie's Eyes: This trait named after a young serpent who escaped the fundament and hides in the water of the material realm grants hell-sight of 40 ft.
Scaled Feat: The fundament has harsh waters and ground to walk on. Your lineage has adapted granting you the ability to walk over all difficult terrain at no penalty and not take damage from walking over hazards.
Bird Hood of the Fundament: You have waterproofed wings that normally flush with your back. They can be sprouted once per day for 1 minute granting a flight or swimming speed of 35 ft.
Shadow Trait.
Shadow Deception: You may use a minor illusion that appears and a pitch black version of what you desire it to be. This can only be done once per day.
Darken: You may darken by one category, the area within your sight for 1 minute. This can be done twice per day.
Blades of Night: You may once per day create a weapon you are proficient in that lasts for 1 minute made of shadow.