Osmosians are an alien species that dwell on the distant planet Osmos (Aggregor once referred to it as Osmos 5). The name "Osmosian" is a play on the word "osmosis", the name of the physical process by which a solvent (i.e. water) diffuses from an area of a high concentration through a semi-permeable membrane into an area of low concentration--it is also the process by which living cells absorb nutrients.
Osmosians are able to absorb, hold, redirect and discharge virtually any type of energy or matter through their bodies, primarily raw energy, such as lightning and electricity, or organic energy, such as a creatures life force and DNA (killing them in the process). According to Dwayne McDuffie, Osmosians can also absorb non-solid forms of matter, such as water and fire, though it is unknown what it does to them physically (ex. absorbing solid matter causes them to grow an outer armor-like skin and allows them to shape-shift their limbs into weapons; absorbing raw energy increases their strength and durability and allows them to hold, redirect, and discharge it at will; absorbing a living creature's life force and DNA causes their body to mutate into a chimeral amalgam and take on all of the creature's powers and abilities).
It is revealed in "Ben 10: Ultimate Alien" that Osmosians have a naturally insatiable hunger for energy that is usually latent. However, if they absorb energy without considering the possible consequences of their actions and dangerous risk involved, they will begin to crave for more, which can cause them to become mentally unstable. Storing energy they have absorbed for long periods of time without discharging it properly can also cause mental instability in an Osmosian. Both features were shown repeatedly in Kevin's debut, where he is shown absorbing energy whenever the opportunity presents itself and how whenever he was depleted of energy he seemed relatively stable. While overindulgence in energy and storing it for periods of time can cause Osmosians to become mentally unstable, it is possible that an experienced and mature Osmosian, like Devin, knows their limits and can control their cravings and discharge energy better than a young or inexperienced one, who give in to their cravings whenever the opportunity presents itself and do not know how to discharge energy properly. This also explains Aggregor's behavior and Devin using electrical energy to fight Ragnarok. why he was so desperate to obtain the newborn Celestialsapien's incomprehensible and immeasurable powers and abilities. This also explains why Kevin began absorbing the life force of whoever he came across to satisfy his insatiable hunger in Absolute Power Part 1 and Absolute Power Part 2 and how his sanity was immediately restored after he was drained of all the DNA and energy he had absorbed.
As demonstrated by Kevin in Alien Force, Osmosians and half-Osmosians are also able to absorb the mass and properties of physical materials and grow an armor-like outer skin as durable as the material used to make it and by extension proportionately increase the Osmosian's strength and durability to even higher power levels. Osmosians can extend their armor to anything they are touching when absorbing matter, as demonstrated by Kevin in Plumbers' Helpers. While absorbing the matter, the Osmosian can also momentarily merge with the actual matter and alter its form by releasing a liquid version of whatever substance they have absorbed and hardening it again. Also, after absorbing matter, the Osmosian can increase its density to shapeshift its limbs into various weapons, tools, and forms.
Even without absorbing energy or matter, Osmosians possess a minor degree of superhuman strength and durability. While not on the same level as Tetramands or Petrosapiens, they are still far stronger and more powerful, and more durable than a baseline human. This has been repeatedly demonstrated by Kevin, who is strong and powerful enough in his normal form to lift and throw the combined weight of several people and resist physical trauma that would severely injure an ordinary human with moderate discomfort. According to Dwayne McDuffie, Kevin's strength, along with that of other Osmosians, does not solely come from the energy and matter he absorbs, rather he possesses a minor degree of superhuman strength and durability in his normal form that is simply increased whenever he absorbs energy or matter. This makes sense, as whenever Kevin absorbs matter, the matter forms a coating of armor but is not a part of his body, meaning that whenever he moves after absorbing matter, he is bending the material to his body movements, which would require more strength than that of a baseline human.Aggregor absorbing an aliens powers
As mentioned in Escape From Aggregor," when Osmosians absorb the DNA and life force of other life forms, they gain that life form's powers. However, they can only acquire the original creature's powers at at least 1/10 of their original potency without mechanical aid. As seen in Ken 10, whenever an Osmosian takes on a chimerical mutation caused by absorbing the DNA and life force of other living beings, the mutation leaves its genetic imprint on their DNA, even after their own genetic structure has overridden the alien DNA. This means that the mutation can be passed down to their offspring. This is shown with Devlin, who has the power and ability to willingly shift between his father's first mutated form and back, though Devlin does not appear to have the same power set-back as his father did (his powers and abilities only being one-tenth of their original strength).
Little else is known about Osmosians so far, except that they are outwardly indistinguishable from humans except for the fact that Osmosians live for hundreds of years, and after about one hundred years when an Osmosian is fully mature, they begin to grow small horns.
- Kevin Levin, one of the main characters, is a human/Osmosian hybrid; one of his parents, his father (Devin Levin), was an Osmosian, and Kevin's mother, Mrs. Levin is human.
- The potential danger from a premature Osmosian's physical and mental state from absorbing raw or DNA energy would explain Kevin's lacked control of transforming into Ben's original ten aliens and then mutation whereas his future counterpart could freely control his absorbed powers. It also explains his aggressive sociopathic behavior in the original series but later becoming relatively well-moraled after returning to his normal physical self. Aggregor however, as a fully-matured Osmosian, has no fear of such danger, as shown in Ultimate Aggregor.
- It is confirmed by Dwayne McDuffie that there is Osmosian DNA in the Ultimatrix.
- It was shown in Escape From Aggregor that Aggregor is also an Osmosian and can absorb any type of power.
- In Fused, Aggregor calls Kevin a hatchling. Probably because Kevin's age, power and experience is far below that of Aggregor- however, the term hatchling could signify an Osmosian method of procreation- laying eggs. It is unlikely to be their only method as Kevin is a Human-Osmosian hybid, and they are therefore capable of breeding with humans.
- If an Osmosian tries to absorb the power of the Ultimatrix or Omnitrix, the Osmosian will become a mixture of most or all of the aliens in the Ultimatrix. This happened to Kevin in 'Kevin 11' when Kevin tried to steal the Omnitrix from Ben.
- The Osmosian home planet is Osmos.
- Osmosians are more advanced than humans.
- In Ultimate Aggregor, Aggregor disagrees with Kevin's belief that uncontrollably or improperly absorbing raw energy causes insanity in an Osmosian. He states that this is simply a lie told by the strong to control the weak. A possible theory is that a fully matured Osmosian might have enough control over their powers to keep a stable mental state, which would explain why a young and inexperienced Kevin was insane since absorbtion of energy is the only power he used in the original series. However, based on Aggregor's personality, Kevin is more right than he realizes, as Aggregor may likely had been driven with insanity and gone mad with power as a result.
- In "Ultimate Aggregor", is confirmed that Aggregor lives on Osmos V.
- Dwayne McDuffie has stated the concept of Osmosian's growing antlers as they age is something they thought of after the episode Paradox, in which Kevin was temporarily turned into an old man, which is why there were none on Kevin's head at the time.
- It is confirmed by Dwayne absorbing energy makes all osmosians insane mature or not.
- Also confirmed that osmosians don't absorb energy unless they absolutely have to.