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
Swedish heraldry typically occur in the crest, rather than on the shield as in Gallo-British heraldry. Also, the use of heraldic furs on the shield, while common in Gallo-British heraldry, is rare in German-Nordic heraldry. Furs in Scandinavia are generally limited to ermine and vair, which sometimes appear in mantling, supporters, or the trimmings of crowns, but rarely on the shield. Consistent with German-Nordic heraldry, the most common charges in Swedish heraldry include lions and eagles. Additional animals that frequently appear in Swedish heraldry include griffins and (especially in the northern provinces) reindeer. Stars are common and are usually depicted with six