What is billy lenz?

Billy Lenz is a fictional character from the horror movie "Black Christmas". He is portrayed as a deranged and violent individual who embarks on a killing spree in his childhood home during the Christmas holiday. Billy is revealed to have a traumatic past, having been abused by his mother and witnessing horrific events that eventually drive him to madness. He wears a mask made of skin and commits brutal murders using various weapons. Billy Lenz has become a well-known figure in the horror genre, known for his creepy appearance and unhinged behavior.