Skull, known as Black Ghost Skull, is the enigmatic and menacing main antagonist in the anime and manga series Cyborg 009. He is the leader of the nefarious organization Black Ghost, which is responsible for transforming humans into cyborg soldiers to fuel global conflicts. Skull is characterized by his skeletal mask and cold demeanor, orchestrating many of the challenges faced by the protagonists. His mysterious identity and relentless ambition make him a formidable and memorable villain throughout the series.