Wolf Bane
This bright purple plant was used to kill werewolves. The Europeans first discovered its toxicity when they dipped the tips of their arrows with the flower’s toxin and used it to kill werewolves, to stop them from eating their livestock. They contain highly toxic cardiotoxins and neurotoxins, which means they’ll affect your heart and brain. Users will get chest pain, palpitations, tachycardia, nausea, vomiting, abdominal pain, and diarrhea (Pubmed).