Roman Godfrey: 

The charismatic eighteen-year-old CEO of Godfrey industries, as well as an Upir (vampire.)  Outwardly arrogant and cold, Roman struggles to resist his biological lust for blood, and spends most of his time trying to be a good father to his illegitimate infant daughter, Nadia, and to be a good friend to his companion, Peter Rumancek.  He is a loving big brother to his deformed younger sister, Shelley, but loathes his abusive mother, Olivia, with whom he shares a dysfunctional and sometimes disturbing relationship.  

Peter Rumancek:  

A vagrant Romani teenager and a werewolf.  He is best friends with Roman, despite the vast differences in their lifestyles and personalities, and cares deeply for his mother, Lynda, and his cousin, Destiny.  Despite having an outgoing and kind personality, in high school, he was treated as an outsider due to his race and rumors that he was a werewolf (which turned out to be true.) 

Olivia Godfrey:

Also an Upir and mother to Roman and Shelley.  Cold, manipulative, and bloodthirsty with psychopathic tendencies and an affection for her son that borders on sexual.  Usually filling the role of primary antagonist, Olivia forced Roman to rape his cousin (or possibly half-sister,) resulting in the birth of Roman's daughter and the estrangement of her and Roman's relationship.

Shelley Godfrey:

Olivia's deformed, re-animated daughter as well as Roman's younger sister.  Despite physical deformities, Shelley is sweet, intelligent, and noble, as well as probably the only truly sane member of the Godfrey family.  She is often protected by Roman, her older broter and gaurdian, who keeps her safe from bullies and her mother, who is alienates Shelley and treats her like a freak.

Destiny Rumancek:

Peter's psychic/prostitute cousin, Destiny cares deeply for Peter and often helps him and Roman on their seemingly insane quests using her unique abilities. 

Lynda Rumancek:

Peter's mother and confidant with whom he shares a close and loving relationship.  She loaths Olivia, but soon accepts Roman as a friend, despite his Upirism. 

Nadia Godfrey:

Roman's infant daughter, and the product of his unuion with his cousin/half-sister, Letha.  Nadia demonstrates supernatural powers and shows multiple signs of Upirism.