Cogliostro, also simply Cog, is a character appearing in Todd McFarlane's Spawn comic book series published by Image Comics. Cogliostro was created in 1993 by author Neil Gaiman and artist Todd McFarlane and introduced in Spawn issue #9. Originally depicted as a supporting character, he becomes an antagonist as the series progresses, eventually becoming the supervillain Sinn, one of the main antagonists of the series. His true identity is Cain the first murderer and the first Hellspawn.