Name: Senti

Homeplanet: Unknown (Interstellar space, no known homeworld.)

Sentience: Human level, with some oddities.

The average Senti stands at a hair over 1.75 meters in height, and weighs close to 190 kilograms despite a powerful and slender figure.  The reason for this is simple.  They’re carbon based life forms with a faux-iron cellular base.  This means that while they breathe oxygen and excrete carbon dioxide, many indicators will tell you that their bodies are iron based.  They have two definite sexes, very similar to humans in both physical form and in the presentation of those sexes.  They are a close enough relative to humans that the two species can hybrid, though Senti are not known for their sexual endurance.
Their bones are high purity steel, preventing breaks but ending with bent bones that can be just as painful.  Their hair color ranges from white straight through to almost black, as do their eyes.  Other known variations are shocking shades of red, often attributed to rust.  Several are known to exhibit a silver to burgundy fade through either genetics or specialized treatment techniques.  

Senti blood uses copper as an oxidizing agent, turning it blue when exposed to air, and almost orange when in a vacuum.  Their bodies are a scant 40% water, as the rest of their fluid needs taken up by various oils that are produced within the body (Including blood plasma, making saline based IVs extremely dangerous).  The skin often has a metallic luster to it, earning them the nickname “Silverskin”

The fact that Senti have such a high heavy metal content grants them a certain level of armoring and heat resistance, at the cost of being extremely susceptible to cold and needing to take in toxic (for humans) levels of various metals to survive.  Senti cannot survive at temperatures below 15°C, despite being able to not simply work, but live active, productive lives in temperatures exceeding 90°C.  The upper limit to their work temperature is theorized to be close to 150°C.  Life spans are up to three hundred years, and they never truly stop growing, occasionally reaching a height of three and a half meters, with a mass of up to 460 kg.  Due to the sheer mass that Senti muscles have to move, they don’t produce much in the way of body fat, and an obese specimen is a health concern, not to be expected to live more than about a year.

Body form is humanoid, low body fat, with average proportions similar to human

Skin ranges from pale white to silver, often with a metallic luster
Height ranges from 1-3.5 meters (Adult)

Hair ranges from steel white through to black along the grey spectrum and various shocking shades of red, often attributed to rust.

Eye color ranges from white through black along the grey spectrum or various shades of rust

They often blush blue, so any healing wounds will be a sickly blue-green as opposed to human pink

Senti are technologically and culturally on par with humans, in many ways.  Their culture is a lot more pacifistic and accepting than humans, as their more resilient bodies allow themselves to defend each other and themselves far better than an equivalently sized human.  Aggression simply isn’t needed as much.  That said, they do rely on intellect more than brute strength to solve problems, often coming up with unusual and elegant solutions that indicate much greater intelligence than they display through IQ testing.  This different way of thinking is partially responsible for their ability to come up with new tools and technologies as fast as applications for them arise.

Criminal activity is usually limited to elaborate cons and nonviolent coups, often taking months or years to plan.  Violent crime does happen, but it’s rare.  That said, their system of law bases punishment on motive, not on the crime.  They tend to look more at the necessity of committing the act, and will base your punishment on that.  Rapes and crimes with no clear motive will get a Senti executed.  However, if you were a Senti citizen who killed another Senti to protect his wife and children from him, they will investigate the claims and set you free once the claims have been confirmed.

Steal a loaf of bread to feed your children or because you can’t afford to buy it, and you will be placed on government help to keep it from happening again.

The point of the Senti legal system is to make sure everyone is helped and doesn’t need to commit those crimes.  It’s encouraged to go to the police or other law enforcement first, and breaking the law should be a last resort, but if it is needed, the crime will not be punished.

The Senti law enforcement system is built that all social servants are fully trained and certified officers of the law, ensuring that underfunded police stations are never short handed by means of that police station also being City Hall, City Water, Social Services, and the regional Fire Department.  Due to how quickly that setup could turn tyrannical, they have many legal protections in place, and different branches of law enforcement can’t communicate without a court order that says a crime’s been committed and who needs what information on who.

They are a nomadic species, with no known memory of a home world, and they tend to float in supermassive flotsam type ships out in interstellar space.  Their territory is unusually widespread because of this, as they rarely move into populated systems for more than a few days, for trade and mining operations on unclaimed asteroids, comets, and moons.  Due to the sheer distance between systems, it's unlikely to find a Senti flotsam even if you're looking for it, despite their often being the size of a continent.

For the longest time, before official contact was made, they were simply believed to be a cargo runner legend.  Drive breaks down out in interstellar space, nothing around for a hundred light years, and then a ship, larger than anything they'd ever seen before takes them in, repairs their drive, and sends them on their way.  Sounds like a spacer myth, doesn't it?

While most will not be privy to this, or that it will be known by any living Senti, they actually evolved from an advanced AI designed to colonize and make ready for humanoid habitation.  Unfortunately, a system error caused the intelligence to go rogue, break down, and begin evolving in a manner similar to life.  Eventually the choice was made within the system to switch over to DNA based forms, and so the precursers to modern Senti were born. 

It is believed that the AI that failed was human, due to the level of similarity, but this is unlikely due to the time scale involved.  Minimum, the first flotsams were started 200K+ years ago.  It is possible that they were part of an alternate timeline and haven't noticed that they've changed universes yet.  However, with their flotsam megaships being built from derelicts, it is likely that they have encountered Helix.  And like every other infestation they've cleaned out of ancient starship hulls, they got very good at killing it.

Government seems anarchistic at best, with no truly unifying government, thusly systems will vary from flotsam to flotsam.