The word wyvern was derived from the Anglo-Saxon word wivern, which means serpent. The Saxon origin story claims that fire monsters fell from the sky (meteorites?) to bury themselves deep in the ground never to come out as they guarded their treasure. According to mythology, wyverns are aggressive by nature, and will attack anything in sight that might make a tasty meal. In the middle ages, the wyvern was an allegory of Satan, and associated with war, pestilence, sin and it was said that they spread the plague. The Renaissance author Dante mentioned wyverns in his famous work the Inferno,​ describing them as one of the creatures in Hell, and artist Leonardo da Vinci recorded an encounter he observed between a lion and a wyvern. Wyverns were also an important heraldic emblem and represented war, envy, might, conquest and strength. In heraldry, the wyverns war-like attributes were used to put fear in the heart of the enemy. Wyverns, while close relatives of the dragons, are fundamentally different. The wyvern has a distinctive two legged stance and their wings are true wings derived from the forelimbs like those of bats and birds. The wyvern has eagle-like talons, a beak-like jaw as well as a deadly barbed stinger at the tip of their tail. Wyverns typically live in caves or similarly protected lairs commonly found in forests and woods. The lairs can be identified by the debris of bones and valuables. Like dragons, they are attracted to shiny objects and baubles but are far less discerning and their hoards will contain as much rubbish as gold. Wyverns continue to be popular today, for example the wyvern appears on the flag of Wales and the wyvern is also extensively used as logos and mascots tor businesses and schools. Wyverns are also prominent in the entertainment industry and include "Game of Thrones" and "The Hobbit: the Desolation of Smaug".