One of the most famous creatures from European lore, werewolves are deadly adversaries. They have the brute strength and sheer speed that allows them to square off evenly with Vampires, their rivals.
They get their strength at night, and their power peaks at the full moon, and in that night, they become damn near impossible to kill. However, the opposite is true for the new moon, where the lack of lunar beams hinders them greatly.
If they bite a plain human, and the bite mark starts to blacken, cut off the limb fast. Like vampires, werewolves have the option to make more of their kind by using a virus in their saliva that forcibly coverts the infected into werewolves.