Operating in the Soviet city of Kuybyshev during the 1960s, Serebryakov carried out a series of killings marked by extreme violence against nine victims, with three others surviving serious injury. His crimes remained largely obscured within the Soviet system, which was notoriously reluctant to acknowledge the existence of serial murder on its soil — a suppression that shaped both how such cases were investigated and how little reached public record. The epithet he acquired reflects the lasting impression his particular brutality left on the region.