Hunter was a hunter who died prior to November 2, 1983 but was possessed by a demon. After the death of Mary Winchester, the demon took on the role as an ally of John Winchester during his search on what killed his wife.
Before his death, Hunter was a respected man in his community though his death was not known even to other hunters such as Ichi or William and Ellen Harvelle despite being a frequent visitor of the Harvelle's Roadhouse.
History[]
Sometime before November of 1983, Hunter died of unknown causes but became the vessel of an unknown demon who continued to live as the deceased hunter while under the orders of Azazel.
When John and Jacob Campbell set out to uncover the truth of a hellhound's tooth with inscriptions on it, they came across a graveyard which housed a tombstone though once opened, a hellhound was released which killed Jacob. When it set its sight on John, it was shot away by Hunter who posed as a friend.
After saving John, the two returned to the Impala where John insisted on taking Jacob to a hospital though Hunter refused due to the wounds not being explainable and instead convinced John to drive to a cliff where they made the death look like Jacob had been in a car accident that resulted in him going over the edge.
When Hunter met John's sons, Sam and Dean Winchester, he introduced himself as an uncle when Dean questioned who he was before the group drove to the Roadhouse where Hunter got Ellen's attention and introduced her to the Winchesters. Once seated, Hunter introduced John to another hunter named Ichi who explained that he was on his own case hunting down a heeler to which Hunter offered to help out with by taking John to which Ichi agreed to.
Out in the woods, Hunter and his two allies attempted to track down the creature and came across the cabin only to find it empty. The heeler, which was a shapeshifter in disguise, then appeared and attacked John before Hunter and Ichi saved the new hunter. Back in the safety of the Impala, John lamented on how he was not capable to be a hunter due to not being able to shoot the creature away from him despite it being in close proximity though Hunter explained to him that despite the life of their kind not being easy, it was worth doing to save lives and stop the evil in the world.
Once parked outside the Roadhouse, John and Hunter noticed Ichi's wound though though the former eventually admitted to John that Ichi had been dead since he left to chase down the heeler and that it was a shapeshifter and that the Ichi with them was the shapeshifter as it had the same leg wound Ichi had caused. Realising there was no point in hiding its true form, the shapeshifter then went to attack the two hunters but Hunter convinced John to shoot the monster which was witnessed by Dean and Ellen whom did not realise that it was not Ichi.
After John left his sons in the care of another couple for a few weeks, he and Hunter set off to find out what happened to Mary with Hunter advising John to write down what he learned in his journal. During the drive, John ordered Hunter to stop the car so he could have a breather and although Hunter obliged, he told John that he had to make sacrifices so that their would could be safe before the two continued their journey.
On November 17, 1983, the two worked on a case involving a man by the name of Doc Benton who stole organs from his patients in order to grow stronger. Although Hunter attempted to put the spirit to rest, Benton was killed by John using a chainsaw. Despite Benton being killed, Hunter berated John for being so reckless though the latter insisted he just wanted to see Mary again after telling his associate about their honeymoon in 1978 and that Dean was born the following year in 1979.
In Blue Earth, Minnesota, Hunter introduced John to a priest named Father Jim who was a believer in the supernatural, after Jim helped John to see Mary's spirit only for a hellhound to appear, John and Hunter soon left for Tempe, Arizona to meet back up with Fletcher Gable for more answers. Inside, the three went over possible links between the tooth and the inscription of 11:27 written on it which John recognised as the time of his wife's death, the two hunters then journeyed to Hope, Colorado.
Parked outside an antique store ran by a man named Sal, Hunter and John questioned him on the location of a graveyard which he told them though remarked on how it was only ever visited by people who were vague in what they were looking for unaware they were hunters. Once back in the Impala, the two made their way to a place called the Fore Inn, on the road, John hallucinated running over his sons only for them to be dead boars which Hunter pointed out before the two continued through the weak storm. When it became impossible to drive through due to a rockslide, Hunter and John went on foot.
Crossing a bridge, one plank broke under Hunter's feet and he fell though John grabbed his hand in time only for the former to loose his grip and drop into the river below. He was then rescued by John who dived down in order to rescue him. They then came across Forever Circle Cemetery where once inside, Hunter investigated a tombstone which set on fire and the two ran once they were chased down by hellhounds. Safe from the danger, the two then came across another problem in the form of the rockslide though they moved across it and found the Fore Inn.
When John demanded Hunter's gun so that he could kill it, Hunter confessed that the beast did not work for anyone in the Inn but instead worked for him. During his confession, Hunter mocked and taunted John for being so trusting in him despite being a stranger. When John accused the former hunter before him to be Mary's killer, Hunter admitted that he was not the one being the death but that he knew who was. Once John made his way through the Fore Inn, he came across Hunter outside who tied him up where John realised the man who he had trusted was a demon, Hunter further confessed that although he knew Azazel, he had never met him but knew that the Prince of Hell had instantly left after Mary died.
Death and aftermath[]

Freed from his ropes that had kept him tied up, John then engaged his former ally in a fight where he shoved the demon off the rooftop and down into a river which resulted in his death.