A patterned cone shell on a tropical beach looks like a souvenir. Inside is one of the fastest and most venomous predators on the planet. This episode explains how the cone snail, a family with roughly 33 million years of evolutionary history, solves the problem of a slow animal hunting fast fish. It tracks sleeping prey by scent using an organ called the osphradium, loads a hollow barbed tooth made of chitin into its proboscis, and fires it with hydrostatic pressure at up to 90 kilometers per hour. The venom that follows freezes a fish before it can thrash.

That same venom can kill a person. Larger species strike hard enough to pierce a neoprene wetsuit, and the geography cone is nicknamed the cigarette snail for the time a victim supposedly has left. Yet the toxins are so precise that researchers call them nature’s pharmacy. The episode covers the painkiller ziconotide, the weaponized insulin some species release into the water, and the centuries of shell collecting that left scientists with more than 3,200 species names to untangle before DNA testing settled the question.

• The harpoon accelerates at 400,000 meters per second squared. Hours after a meal the snail regurgitates scales, bones, and its own spent harpoon.
• Medical literature records about 27 human deaths, and the venom includes a painkiller, so victims may feel little agony as paralysis and respiratory failure set in.
• A single species can make up to 200 active peptides, with roughly 50,000 unique conopeptides estimated across the family.
• The geography cone and tulip cone release insulin that sends fish into a hypoglycemic coma. Because it does not clump, it is a model for faster acting human insulin.
• The glory of the seas cone was once locked in bank vaults as a priceless rarity, until its habitat was discovered and the market crashed.