The Basilisk

In European legends, a basilisk is a legendary reptile said to be king of the serpents and to have the power to cause death with a glance. According to Pliny the Elder, the basilisk of Cyrene leaves a wide trail of deadly venom in its wake, and its gaze is likewise lethal; its only weakness is the odor of the weasel. The legend of the basilisk and its association with the weasel in Europe may be inspired by accounts of Asiatic snakes (such as the king cobra) and their natural predator, the mongoose.

Stories gradually added to the basilisk's deadly capabilities, such as describing it as a larger beast, capable of breathing fire and killing with the sound of its voice. Some even claimed it could kill not only by touch, but also by touching something that is touching the victim, like a sword held in the hand. Some stories even claim its breath to be highly toxic and will cause horrible death.