This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Basilisk (Italian)
In European bestiaries and legends, a basilisk is a legendary reptile reputed to be a serpent king, who causes death to those who look into its eyes. According to the Naturalis Historia of Pliny the Elder, the basilisk of Cyrene is a small snake, "being not more than twelve inches in length", that is so venomous, it leaves a wide trail of deadly venom in its wake, and its gaze is likewise lethal.
Some have speculated that accounts and descriptions of cobras may have given rise to the legend of the basilisk. Cobras can maintain an upright posture, and, as with many snakes in overlapping territories, are often killed by mongooses. The Indian cobra has a crown-like symbol on its head. Several species of spitting cobras can incapacitate from a distance by spitting venom, and may well have been confused with other cobra species by their similar appearance.