Hybrid
Hybrids are the offspring of humans and werewolves. Despite the two species having dramatically different appearances, they are still genetically compatible. The resulting offspring tend to look almost entirely human but with various minor animal traits such as the addition of an extra pair of ears or a tail. Traits that have been observed so far can resemble wolves, foxes, cats or raccoons among others.
Hybrids are the second most common intelligent species after humans, mostly due to their physical similarities and ease of adaptation into human-specific technology and equipment. Because of their superficial resemblance to humans aside from their animal traits, they are often passed off as humans with very little distinction.
Biology
For the most part, hybrid physiology is largely identical to that of humans. However, on average, they tend to have much keener senses of smell and hearing than most humans. While they tend to have much better nightvision, colorblindness tends to be a lot more common, usually of the red-green variety.
History
The origins of hybrids were largely considered unknown for most of humanity's spacefaring history. Most information comes from a rare eyewitness from John Veer, a human astronaut from the distant past that was transported far into the future. According to him, the concept of hybrid human-animals have existed since before humanity became an interplanetary society. The first experiments into creating hybrids were funded by Shinichi Nekomata, an enigmatic, wealthy philanthropist from the ancient Earth nation of Japan. He pursued these ventures motivated not by profit but purely on the basis that he wanted a world where catgirls existed.
Initial experiments were not quite as straightforward as simply using cat DNA alone failed to achieve desirable results. Thus, they eventually came to incorporate traits of other animals which produced an entirely unintentional species - the werewolf. Eventually, after many years of more experimentation, a catgirl was conceived. She was named Mei and was adopted by Shinichi to raise as a daughter.
Unfortunately, at age 15, Mei was diagnosed with cancer and suffered a variety of other health complications, possibly as a byproduct of the experiments. This was not helped by the fact that eventually, the United Nations came to ban genetic engineering following a conflict where some nations began to create genetically engineered soldiers through mass cloning. In desperation, Shinichi tried to continue looking to cure Mei in secret, but was shortly arrested and imprisoned for life. Shortly following Mei's death, Shinichi went missing from his cell and was never seen again.
Even after the ban on genetic engineering, the stockpile of frozen embryos containing werewolves and hybrids was kept, having evaded attempts by the government to destroy them. They were kept hidden in a secret lab located somewhere in Hokkaido.
By the time the first generational ships were getting constructed, various human embryos were set to be loaded on board as a means of populating the galaxy with minimal crew oversight. Either by mistake or through deliberate intention, some of the hybrid embryos were loaded onto these ships alongside unmodified human embryos. On one particular generational ship that was bound for the planet Loupa was a particularly large portion of werewolf embryos. As such, when these ships arrived at their destinations hundreds of years later, the crew were in for a surprise when some of the embryos grew into humans with animal traits.