Source: Pathfinder 3, pg(s). 26
Kheln is originally from Magnimar, but fled town for Sandpoint after losing all his wealth to treacherous family members and being involved in a theft gone bad. He slept in alleyways while trying to avoid the notice of investigators from Magnimar. While in these desperate straights, he was approached by a mysterious stranger with a proposition to steal a silver medallion from a secret compartment in a statue in Pauper's Graves. Kheln did as the stranger indicated, but was betrayed, as the stranger was Kanker, a ghoul priest of Kabriri. The medallion conferred protection over the graveyard, but was rendered powerless by the theft.
Kheln was infected with ghoul fever, died several days later in Sandpoint, and rose as a ghoul. He has made Paupers' Graves his home for the past several years. He has infected others, turning them into ghouls and worked with Kanker to alchemically transform dogs into ghoul hounds.