Skull (スカール Sukāru) (known in the english series as Black Ghost) is the main antagonist in Cyborg 009. He is the tyrannical leader of the arms dealing organization Black Ghost. His true identity is not known. He wears a skull-shaped helmet, and an all-black suit (which has what appears to have what looks like ribs) followed by a red cape. A possible origin for him exists in the 2007 anime adaptation of The Skull Man in which main character Hayato is revived and takes up an appearance almost exactly like that of Skull.
Skull was almost killed when the 00 cyborgs entered Black Ghost's Base (what they thought was Black Ghost HQ until later in the manga and anime) and set explosives leaving 009 and Skull to fight one-on-one. It is revealed that Skull is not only a cyborg, but a highly advanced cyborg, soundly defeating 009 using his superior acceleration mode. Only a last-ditch effort managed to save the nine cyborgs (009 held on to Black Ghost whilst plummeting into what looked like a vat of liquid nitrate and then 001 teleported 009 to safety).
It is not known how Skull survived the explosion. In addition to Skull apparently being a cyborg himself, the true leaders of the Black Ghost Organization turn out to be three brains. Although the 3 brains were destroyed in the end, they claim to be only a part of the entire Black Ghost organization and that the Black Ghost organization were universal and they were just the leaders of the Earth branch of Black Ghost and that Black Ghost will exist as long there's evil in men's heart.