Dragons with intentionally humanoid traits created through a genetic morphing process. They were either born this way, or changed over voluntarily. The need for a smaller creature with the ability to finely handle things was needed, so efforts were made to turn some dragons into humanoid dragons based on a cross over between humans and dragons.
Their most distinguished traits is that they move exclusively with bipedal movement on two legs, have hands with thumbs and digits like a human and stand upright. Yet still have the physical traits of a dragon, such as horns, scales, wings, tail, etc. Often due to their more human shape, they are often smaller than most others, so to compensate for this they are given armaments similar to what humans wield. The reason behind the need for Dreu-Kin primarily was because the human body was small, compact, had more mobility in tight quarters and had hands more capable of handling delicate things compared to the big hulky dragons. Dreu-Kin are considered more useful in fine mechanics, not to be confused with that they would be the exclusive workers of the population, they and normal dragons do an equal amount of work.
The process of Morphing into a Dreu-Kin is a drastic physical change and is an extremely sensitive process. The subject normal dragon is suspended in animation while floating in the typical cliche sterile tube. Then they are introduced and given what is needed to begin the transformation and the overall process can take up to two or more years. Workers in this environment wear sealed sterile outfits that cover their entire body and must go through multiple chambers to ensure sterility in the environment they work in. Any slight foreign particle in the room could compromise the sterility of the room, which could cause complications for the dragons morphing, and die. The things that are handled inside these rooms are extremely dangerous and could kill the workers as well.
Normal Public Spaces:
In the normal public space, they are not too terribly numerous so they are a minority in the collective whole. Some treat them as equals, while other times, dragons may be a little condescending, or carry a slightly superior attitude. Usually because Dreu-Kin are not as large or strong as their counterpart.
Blood-Kin Concentration Camps:
Between 1945 and 2007 for 62 years Dreu-Kin on board the Beta were enslaved and being turned into a fighting force with the goal of placing control of the eight ships under the Blood-Kin. Treated to being 'picked on', beaten, and starved. Daily they were constantly threatened, and under constant indoctrination. They were forced to train, and listen to a repeating show of clan leaders telling them to join. On top of this, Dreu-Kin weakened enough to join were often allowed to convince their fellow Dreu-Kin in enslavement to join the Blood-Kin's cause. The Dreu-Kin who joined the Blood-Kin were treated better, but not as equals. They were fed better, and not picked on as much, but they were still treated as lesser beings they acted more as guards or servants. The Dreu-Kin under the fight train regimen were excellent fighters, and some so dedicated that after the Blood-Kin War, they often committed suicide or their minds were broken, taking a long time to mentally recover if at all.
For more info on The Blood-Kin: Blood-Kin History