Even though it's pretty much hated I still enjoy Friday the 13th part 9. I also dug hi a bounty hunter was after Jason as he was the only person who knew how to kill him. The Bounty Hunter in question was Creighton Duke. He had a vendetta against Jason but it was never explained why.
Luckily Adam Marcus, in a Facebook Q&A with Club Voorhees, discussed Dukes backstory
“Here’s what happened. A teenage Creighton was out on Crystal Lake with his girlfriend,” Marcus explained. “Jason capsized their small boat and pulled the girl down into the lake. Creighton tried to save her but could not. She was never seen again. Creighton vowed revenge and from that moment on he spent his life in the study and pursuit of Jason. He became a bounty hunter just to fund his work in taking down his nemesis. That’s the story.”
It feels great to have closure