Half-dragon, half-serpent, the fearsome Guivre prowled medieval French forests and ponds, spreading terror with its venomous breath. The word guivre, meaning wurm, wyvern, or serpent, is a variation on the more common term "vouivre." All these forms derive from the Latin "vīpera," which is also the root for the English word "viper."

Sometimes described as having bat-like wings or bird-like legs, the Guivre was a frightening symbol of evil and witchcraft. It would attack humans unprovoked—unless, strangely, they were naked. That's right: the Guivre's peculiar vulnerability to nudity meant it would slither away in embarrassment at the sight of an unclothed person. So, if you ever find yourself time-travelling to mediaeval France, perhaps consider packing a flasher mac or bathrobe to scare off a prudish dragon.