Jacob McCullum is the son of Vampyr's antagonist Geoffrey McCullum he's a Vampire Hunter and the 2nd Vampyr student at Game High, however do to his father's relationship with the Reid family and their son he serves not just as John's friend but as his personal guard as well.
Jacob is a muscular tall young man with blue eyes, dark brown hair, stubble, Caucasian skin plus he wore a burgundy scarf a blue long coat with a vest and shirt underneath pants plus shoes. He also sports a crossbow on his arm like his father.
Jacob is just like his father, for he's gruff and hostile to all vampires, he even picked up the habit of calling vampires leech. But since his dad was indebted to Johnathan for sparing his life in Pembroook Hospital back when the Spanish Epidemic was still a problem, Jacob had refrained from turning hostile whenever him and John were in the same room together or crossed paths and has grown to be the young Ekon's friend and personal guard. However this never stopped him from calling Reid a leech.