The Vampire isn't a vampire and he did realise that vampires aren't real, but he knew the fear that they inspire is real. He is a human and he is cibopathic. Long ago the Vampire discovered that he could learn the same lessons from blood as he could from flesh. At that point he decided he would present himself as a vampire. So he could learn more. And the more he learns, the more powerful he becomes. However sometimes for more extraordinary people blood wasn't enough, some recipes needed meat.
The Vampire was created by John Layman and Rob Guillory. His first appearance was in Image's Chew #7. At the back of Chew: International Flavor Rob states the concept of The Vampire:
I wanted to mix the classic vampire look with a more crazed serial killer. I based his stiffness and angularity on old-school movie slashers, who never were all that mobile, but were always foreboding.
Major Story Arcs
The Vampire first appears in the second arc of CHEW. In this first appearance you see him kill USDA agent Lin Sae Woo and her rat Jellybean. Throughout the majority of this arc you only see The Vampire kill people and suck out their blood. That is until the last issue where Tony Chu and The Vampire come face to face. The Vampire manages to flee whilst 'rescuing' Fatanyeros.