Dark Reef Dozen

The Dark Reef Dozen was a group of prisoners who attempted to escape from Dark Reef prison. Despite their plans, ten members of the dozen died in the attempt, and two were recaptured and brought back to Dark Reef, where they were executed for the amusement of the other prisoners.

The Hidden Thirteenth
Taking advantage of the commotion, Slark was able to escape Dark Reef, the only inmate ever to do so. After his escape, he headed to southern Shadeshore, where he continues to live today. Slark implies that the Dark Reef Dozen were a bunch of "loudmouths and losers", and thus he preferred working alone.