In 2003, Dean was working on a case that involved a monster that fed specifically on livers. Dean eventually managed to track down Edward and slit his throat. Edward's death would eventually send Cole on a mission to avenge his father and to track down Dean for revenge.
Several years after, when Cole confronted Dean in an alley fight, Dean said he had never seen any monster like Edward before and has never seen anything like him since. He later told Cole that Edward had once been human like his son but that he was transformed into a monster.
Powers and Abilities
It's unknown about his powers and abilities, however he was able to rip livers from his victims easily. He also seemed quite manipulative.
- Super Strength - He was strong enough to snatch livers from the body of his victims.
- Silver-coated Steel Knife - The only thing that effectively can kill him. Dean slit his throat with it.
- Season 10