Wyvern folklore is rarely fire-breathing like the four-legged dragon. Sometimes modern fantasy book and media authors have wyverns that are frost-breathing or poison-breathing instead of fire-breathing. The current spelling "wyvern" is not attested before the seventeenth century as "winged two-footed dragon". According to the Oxford English Dictionary, it is an alteration of Middle English "wyver" (attested thirteenth century), from Anglo-French "wivre" (cf. French "guivre" and "vouivre"), which originate from Latin "vīpera", meaning "viper", "adder", or "asp". Conversely, medievalist William Sayers proposes a more complex origin for the term. He notes that the Anglo-French "guivre" and its Middle English derivative ceased to
Wyvern the coat of arms of the Tilley family. The kings of Aragon of the House of Barcelona since Peter IV used a wyvern as a crest on their helmets. Nowadays this symbol has been officially adopted as the coat of arms of the Generalitat Valenciana (Valencian Parliament and Government). The arms of the Worshipful Society of Apothecaries depict a wyvern, symbolising disease, being overcome by Apollo, symbolising medicine. The wyvern is also a fairly popular commercial logo or mascot, especially in Wales and what was once the West Country Kingdom of Wessex, but also farther afield in Herefordshire and Worcestershire,