Osmosian

Osmosians are an alien species that live in Osmos. 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 various types energy through their bodies mostly electricity and lightning. It is apparently ill-advisable for them to absorb raw energy, such as electricity, as it can effect their physical and mental state. As demonstrated by Kevin in Alien Force, Osmosians and half-Osmosian 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 extention proportionately increase the Osmosian's strength and durability to even higher levels. While absorbing the matter, the Osmosian can also momentarily merge with the actual matter and alter its form. Also, by temporaily absorbing extra matter, the Osmosian can increase its density to shapeshift its limbs into various forms. See Kevin's Abilities for more details.

As mentioned in "Escape From Aggregor," when Osmosians absorb the energy from other life forms, they gain that life form's powers. However, they are only able to use only 1/10 of the original creature's powers and abilities.

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.

Trivia

 * 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, 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 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 may be 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 live in Osmos V, so maybe exist Osmos, Osmos II, Osmos III and Osmos IV and possibly more.
 * 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. He has stated however that they have come up with an excuse for it.
 * Osmosian's could be the most powerful and dangerous species in the Ben Ten universe. Not only can their matter/amor ability make them fairly strong opponents, but they are able to absorb the powers of other creatures and therefore, cannot be overpowered.
 * It is comfirmed by dwayne that abosrbing energy makes all osmosians insane mature or not

Notable Osmosians

 * Devin Levin (full Osmosian)
 * Kevin Levin (half-Osmosian)
 * Devlin Levin (quarter-Osmosian)
 * Aggregor (full Osmosian)