Aconitum Napellus, aka. “Monk’s hood”.
One of Europe‘s most poisonous plants.
All parts of the plant are able to kill you, a few grams are enough. Touching it can already lead to reactions. Fatal dosage of the agent is 4mg. There is no antidote. Keep away from your kids!
It was formerly used to poison arrows, for assassinations, and as wolf poison, and was reportedly an ingredient for witches anoint.