Hamlet’s poison
In Hamlet the king is killed by a poison called “hebenon” poured into his ear while he sleeps. Today it is thought to have been henbane. Henbane was well known to poisoners and executioners in Europe: sixteenth-century accounts from Lucerne record the executioner buying henbane seed. All parts of henbane are poisonous.
Source: Jürgen Leo Müller, “Love potions and the ointment of witches: historical aspects of the nightshade alkaloids”, Journal of Toxicology: Clinical Toxicology 36(6), 1998 (Müller, Clin Toxicol, 1998). This is a folk record, not a treatment recommendation.
Worms falling from the tooth