The basilisk could have originated from the horned adder or hooded cobra from India. Pliny the Elder described it simply as a snake with a golden crown. By the Middle Ages, it had become a snake with the head of a cock, and sometimes with the head a human. In art, the basilisk symbolized the devil and the antichrist. To the Protestants, it was a symbol of the papacy.
According to legend, there are two species of the creature. The first kind burns everything it approaches, and the second kind can kill every living thing with a mere glance. Both species are so dreadful that their breath wilts vegetation and shatters stones. It was even believed that if a man on horseback should try to kill it with a spear, the power of the poison conducted through the weapon would not only kill the rider, but the horse as well. The only way to kill a basilisk is by holding a mirror in front of its eyes, while avoiding to look directly at it. The moment the creature sees its own reflection, it will die of fright.
However, even the basilisk has natural enemies. The weasel is immune to its glance and if it gets bitten it withdraws from the fight to eat some rue, the only plant that does not wither, and returns with renewed strength. A more dangerous enemy is the cock for should the basilisk hear it crow, it would die instantly.
The carcass of a basilisk was often hung in houses to keep spiders away. It was also used in the temples of Apollo and Diana, where no swallow ever dared to enter. In heraldry the basilisk is represented as an animal with the head, torso and legs of a cock, the tongue of a snake and the wings of a bat. The snake-like rump ends in an arrowpoint.