The large snake like serpent, called the Basilisk, about 50 ft long in length slithered out of the chamber of secrets and was hunting the students of Hogwarts. Some students were petrified from its gaze, and it is also known to have a venom so deadly it causes a slow death. It began slithering the halls and was hissing. It was bloodthirsty and could only be controlled by the Heir of Slytherin.