The K-Series are a breed of Xenomorph captured and bred by human scientists hoping to use them as bio-weapons. They are also known as yellow Xenomorphs, because of the color of their exoskeleton.
The K-Series created by Dr. Samuel Kadinski eventually escaped from the human lab, and used the humans as hosts. They constructed their hive within the lab. The normal black strain of Xenomorph would not tolerate the new genetic strain, however; much like the mutated Red subspecies from Aliens: Genocide, the "pure" Xenomorphs outclassed and destroyed the K-Series.
- Aliens Versus Predator: Extinction (First appearance)
- The K-Series likely stands for "Kadinsky Series".