Water Hemlock
Water Hemlock has a sinister history. It’s known for killing Socrates. It contains cicutoxin, and when ingested, it viciously acts on the central nervous system. In worst-case scenarios, it may cause grand mal seizures and death. To poison humans or livestock, you only need a small number of toxins. It may also cause nervousness, agitation, rapid breathing, tremors, and muscle twitching (Best Life Online).