David is Tremor's brother and only remaining blood relative. He wa smanipulated by the Mafia, namely Toni Twistelli, to believe that Tremor was responsible for the loss of his brother and remaining relatives, when in fact, it was Twistelli who murdered them and mangled his brother, Richard (AKA Tremor). He is hesitant to believe the mob had anything but his best interests at heart. He also does not believe Tremor is indeed his brother, despite numerous instances of the creature defending him and not fighting back when David himself attempts to do him in.
Anna-Marie was Richard's loving wife. She was murdered afer his mob funded surgery failed, along with the rest of the family. Together, they had at least one child.
The Baby is the child of Richard and Anna-Marie. It is not mentioned whether the child is a boy or a girl, what its name was, or if it was even born yet. Its loss is felt as much as Anna-Marie's throughout Spawn's various encounters with the angst ridden Tremor.
Spawn (AKA Al Simmons) is Tremors an uneasy friend of Tremor's. They help one another out on occasion, warily. They met during a Turf War that Tremor initiated to distract his Mafia enemies and to garner the attention of the Hellspawn. He got both and an uneasy alliance formed between thm, Simmons himself knowing the bite of betrayal and lust for revenge. He also assisted in David's rescue from the Twistelli family, albeit crippling his leg in the process.