What creature lives in the Chamber of Secrets?

The story behind the answer

Basilisk is correct. The Chamber of Secrets was built by Salazar Slytherin, who prized serpents and Parseltongue; he hid a colossal snake—the Basilisk—there to purge the school of those he deemed unworthy. Its deadly direct gaze can kill, while indirect glances cause petrification, which is why victims in the book are “petrified,” not dead. Harry ultimately defeats it with help from Fawkes and the Sword of Gryffindor.

Memory tip: Slytherin sl