The Basilisk (King of Serpents)

The Basilisk is a gigantic magical serpent known as the King of Serpents. It is an exceptionally dangerous Dark creature, classified as XXXXX by the Ministry of Magic, a rating reserved for known wizard killers that are impossible to train or domesticate. Bred by Dark Wizards, the Basilisk possesses a gaze that causes instant death and fangs containing a highly potent and destructive venom for which Phoenix tears are the only known antidote. A specific Basilisk, created by Salazar Slytherin, resided within the Chamber of Secrets at Hogwarts School of Witchcraft and Wizardry for nearly a thousand years. Its purpose was to purge the school of Muggle-born students, and it could only be controlled by a Parselmouth, an ability possessed by Slytherin and his heir, Tom Riddle.

The Basilisk that inhabited Hogwarts was placed in the Chamber of Secrets by its creator, Salazar Slytherin, before he left the school. It was intended to lie dormant until Slytherin's true heir arrived to unleash it upon the castle. In the 1942-1943 school year, a sixteen-year-old Tom Riddle discovered the Chamber of Secrets and used his ability to speak Parseltongue to command the Basilisk. He unleashed it upon the school, resulting in several attacks and the death of a student, Myrtle Warren, in a girls' bathroom on the second floor. Following Myrtle's death, Headmaster Armando Dippet threatened to close the school permanently. To prevent this, Riddle framed Rubeus Hagrid and his pet Acromantula, Aragog, for the attacks. Riddle then sealed the Chamber, but not before using Myrtle's murder to create his first Horcrux: his diary. Fifty years later, during the 1992-1993 school year, the memory of Tom Riddle preserved in the diary was able to influence Ginny Weasley, who had come into possession of the Horcrux. Through Ginny, Riddle once again opened the Chamber and unleashed the Basilisk. The creature roamed the castle through its plumbing system, launching a series of attacks. Those who saw its reflection were Petrified, including Mrs Norris the cat, Colin Creevey, Justin Finch-Fletchley, Nearly Headless Nick, Penelope Clearwater, and Hermione Granger. Harry Potter, aided by Ron Weasley and Gilderoy Lockhart, discovered the entrance to the Chamber. Inside, Harry confronted the memory of Tom Riddle. Riddle summoned the Basilisk to kill Harry, but Albus Dumbledore's Phoenix, Fawkes, came to Harry's aid, blinding the serpent with its talons and neutralizing its fatal gaze. Fawkes also delivered the Sorting Hat, from which Harry drew the Sword of Godric Gryffindor. Harry used the sword to slay the Basilisk but was simultaneously stabbed by one of its fangs. He was saved from the venom by Fawkes's healing tears. Harry then used the Basilisk fang to destroy Tom Riddle's Diary, vanquishing the memory of Riddle. The Basilisk's carcass remained in the Chamber, and its fangs were later used by Ron and Hermione to destroy another Horcrux, Helga Hufflepuff's Cup.

The Basilisk of Salazar Slytherin was a serpent of monstrous size, described as being as thick as an oak trunk and at least fifty feet long. Its scales were a brilliant, poisonous green, and it had a large, heavily-boned head. Its most prominent features were its great, lamp-like yellow eyes, which served as the conduit for its deadliest weapon. After being blinded by Fawkes, these eyes were ruined and bleeding. As a creature of Dark Magic, the Basilisk was malevolent and bred solely to kill and obey the commands of a Parselmouth. It displayed cunning and patience, having remained dormant for centuries and effectively using the castle's pipework to move undetected. Its primary instinct, besides obeying its master, was to attack. It is known that spiders, such as Aragog and his colony, fear the Basilisk above all other creatures and will flee from it.

• Deadly Gaze: The Basilisk's most powerful and infamous ability. Anyone who looks directly into its eyes dies instantly. An indirect look, such as through a reflection in a mirror or water, through a camera lens, or through the semi-transparent body of a Ghost, results in Petrification.
• Venom: The Basilisk's venom is exceptionally potent and destructive. A single drop can kill a person in minutes, and there is no known magical cure besides the extremely rare tears of a Phoenix. The venom is also one of the few substances capable of destroying a Horcrux, as it is so powerful it damages an object beyond magical repair.
• Longevity: Basilisks can live for an exceptionally long time. Slytherin's Basilisk was approximately one thousand years old at the time of its death.
• Mortal Weakness: The crowing of a rooster is fatal to a Basilisk. This is the reason why all the roosters at Hogwarts were mysteriously killed during the 1992-1993 school year, an act carried out by Ginny Weasley under the control of Tom Riddle's diary to protect the serpent.

The Basilisk was not a creature capable of complex relationships; its primary connection was one of servitude to its masters.

1. Salazar Slytherin: As its creator, Slytherin was the Basilisk's original master. He designed the creature to carry out his dark will of cleansing Hogwarts of Muggle-borns.
2. Tom Riddle (Lord Voldemort): As the heir of Slytherin, Riddle was the only other known wizard to command the Basilisk. He used the serpent as a weapon to terrorize the school during his own time as a student and again, through his diary Horcrux, fifty years later. The Basilisk showed absolute obedience to his commands in Parseltongue.

The name Basilisk is derived from the Greek word basiliskos, meaning “little king.” This is reflected in its common title, “King of Serpents.” In European legends, the basilisk is a mythological serpent reputed to kill with its glance, breath, or touch, and is often associated with being hatched by a toad from the egg of a cockerel, which explains its fatal weakness to a rooster's crow.

• According to the textbook Fantastic Beasts and Where to Find Them, the first recorded Basilisk was bred by Herpo the Foul, a Greek Dark Wizard and Parselmouth. He accomplished this by hatching a chicken egg beneath a toad.
• The breeding of Basilisks has been illegal since medieval times and is monitored by the Department for the Regulation and Control of Magical Creatures. (Fantastic Beasts and Where to Find Them)
• In the film adaptation of Harry Potter and the Chamber of Secrets, the Basilisk is depicted as a colossal creature, significantly larger than the fifty feet mentioned in the novel, and its design includes a frill of horns around its head. (film)