Harry Morgan, portrayed by actor James Remar is a pivotal character and narrator of the hit television show Dexter on HBO. He is Dexter’s father and the main reason for why Dexter Morgan ‘is the way he is’. He is also what Dexter refers to as his dark passenger, seeing that Harry Morgan always seems to be playing a role in Dexter’s life and mind.
Quick Bio from Wikipedia:
Harry Morgan is a detective and highly-respected member of the Miami Police Department, and a close friend of his immediate superior Lieutenant Tom Matthews. In the course of a high-stakes drug case, Harry begins an illicit relationship with Laura Moser, Dexter’s biological mother, to gather information and evidence on the drug lords in question. The drug dealers eventually find out she is informing on them, and make an example of her; they brutally murder her and three others with chainsaws in a shipping container. Her sons Brian and Dexter are left in the container for several days, sitting in two inches of blood, until Harry and a police team rescue them. Harry adopts Dexter, while Brian is sent into foster care; Harry believes that the older Brian is permanently traumatizedby the event and is “unsalvageable”, but that Dexter is still young enough to be “saved”. Eventually, however, Harry realizes that the experience turned Dexter into a violent sociopath. (Unbeknownst to him, the same fate had befallen Brian, who also grows up to become a serial killer.)