Werewolves

Werewolves are one of the many mythical creatures of the world.
Considered by many to be "the monster within" when it comes to humans, werewolves are the result of a curse.
Colormen research into the origin of werewolves has yielded little results; however the nature of the werewolf itself is well understood.
For most days of the year, werewolves are normal people, with some individuals even living among normal people. But once the full moon goes up, an uncontrollable transformation takes place. The "human intelligence" is replaced by a "beast level" intelligence, and the resulting transformation makes the being stronger, faster, increased stamina, etc. During the werewolf state, the human mind more or less is asleep; they are not conscious of their actions nor do they have control over their werewolf bodies. They prey on humans as both a food source and to spread the curse. All it takes is a bite, or a deep gash to spread the curse. Research into them seems to indicate that the werewolf curse is not spread through reproduction.
Killing a werewolf is straightforward, but dangerous. They are not weak to religious artifacts, but they are to silver. Ancestrally, silver blades were used to kill them, and with the advent of gunpowder, silver bullets were developed by the Colormen in secret.
However, once the werewolf is dead, the job is not done. The head must subsequently be cut off and the whole body burned; otherwise three days later it will return to life as a werewolf zombie.
In Colormen history, they were among the first to recognize the werewolf threat, and sought to combat it. Developing methods and tactics that allowed them to fight the curse, every full moon traps were set to lure werewolves to specific areas... then once cornered, the Colormen used Silver to finish them off.
Interestingly, there were also thousands of recorded cases of humans coming to the Colormen asking to be killed, because they knew they were werewolves and did not want to hurt anyone anymore.