Clostridium tetani
According to Homer's epic poems about the legendary Trojan War, the "Iliad" and the "Odyssey," spears and arrows were tipped with poison. During the First Sacred War in Greece, in about 590 BC, Athens and the Amphictionic League poisoned the water supply of the besieged town of Kirrha (near Delphi) with the toxic plant hellebore. According to Herodotus, during the 4th century BC Scythian archers dipped their arrow tips into decomposing cadavers of humans and snakes or in blood mixed with manure, supposedly making them contaminated with dangerous bacterial agents like "Clostridium perfringens" and "Clostridium tetani", and snake venom.