Parker is the leader of the Streetwolves, a motorcycle gang that had a reputation for being particularly vicious, and has been for over ten years. Capable of controlling his bestial spirit better than the other lycanthropes, he has to fight challengers mistaking his caution for cowardice and weakness.
In the series
In Fool Moon, Parker first encountered Harry Dresden when he, following a lead from Roger Harris, walked into the Full Moon Garage; accidentally encroaching on Parker's territory and endangering his people. As he escaped, Dresden soulgazed Parker, seeing the spirit of rage behind his eyes, and that the only reason Parker didn't kill him right then was that he had to do it alone in order to prove his strength.
Parker and the Streetwolves attempted to find Dresden at his house and office, but failed, as Dresden has been in hiding. Then they hear that he had been arrested on the police scanner, and they camped out at the bar across the street from the police station and waited. After the loup-garou's attack, Parker and his gang tailed Dresden in stolen cars.
Dresden jumped out of his car in order to confront Parker, and managed to wreck the Streetwolves' cars and shoot Parker in the knee cap before being captured and taken to the Full Moon Garage. There Parker intended to kill Dresden, but does not do so right away as part of a deal with Marcone. Thinking that this is a sign of weakness, Flatnose challenged Parker and was swiftly defeated. Marcone offers Dresden a way out by signing on as one of his employees, violating the deal he had with Parker. Parker and Flatnose attacked Marcone and Hendricks while Dresden attempted to escape. Then the FBI hexenwolves showed up and started shooting at the streetwolves and Dresden. Lana and Flatnose are killed in the ensuing battle, and Parker was torn apart and eaten by three of the hexenwolves.