A Basilisk is s giant serpent, sometimes referred to as the King of Serpents. Bred by Dark wizards by hatching a chicken egg beneath a toad.
/ˈbas el əsk/
The first basilisk recorded being bred was bred by the Dark Wizard Herpo the Foul, who, after much trial and error found that a chicken egg hatched beneath a toad would produce a gigantic serpent with extraordinary powers. As a Parselmouth, Herpo the Foul was able to control basilisks. The breeding of basilisk was banned in Medieval times, and as such, the Ministry of Magic claimed all chicken coops within the wizarding world were subject to Ministry inspection to thwart the practice of basilisk breeding. This method proved simple to avoid, as those attempting the practice would simply remove the egg from underneath the toad whenever the chicken coop was checked by the Department for the Regulation and Control of Magical Creatures. Most Dark wizards shied away from breeding basilisks, as only Parselmouths were able to control the creatures. One of the Hogwarts School of Witchcraft and Wizardry’s founders, Salazar Slytherin, was responsible for breeding a basilisk and keeping it hidden in the Chamber of Secrets beneath the school. In 1943, a girl named Myrtle Warren was killed, when He-Who-Must-Not-Be-Named opened the chamber. The chamber was again opened in 1993, when an artifact belonging to He-Who-Must-Not-Be-Named came into the possession of a First Year by the name of Ginevra Weasley, this artifact forced her to do its bidding releasing the basilisk once again. Though no students perished, several were petrified due to catching the basilisk’s glare through a reflection. The basilisk was slain when Harry Potter stabbed it with the Sword of Gryffindor.
“Basilisk” comes from the Ancient Greek words “basil(eus)” meaning “king” and “iskos” a diminutive suffix, combined meaning “princeling.”