Wolfsbane is a well known plant. As its name suggests, it acts as a repellent to Lycanthropes or werewolves. Wolfsbane, alongside silver, has been used numerous times by many hunters around the globe as a way to kill rampant werewolves. When mixed with bait and devoured by a lycan, or even placed upon arrowheads, knives, swords and so forth, it is then fired and strikes the wolf causing it writhe violently in pain and in the end pass away from the fatal toxin.
Wolfsbane can also be used by vampires as well, however, despite it being fatal to werewolves, it can cause irritation to the vampires and are thus required to place a protective gear on themselves. The fluids of the wolfsbane is deadly, but its mere scent can drive a werewolf to madness as well. In fact, it is said that a mere whiff of the plant itself will forcibly turn a werewolf into a violent and savage animal, even if they are in human form. Although the process is slow when in human form, as the human will feel as though they've caught a severe fever.