Koorst was a Trandoshan male, from the Legends timeline, working as a bounty hunter. He became the student of Vril Vrakth, a Zabrak. Together with Vrakth, he traveled to Nizon during 19 BBY.
Koorst's initial introduction occurred in the 2008 release of The First to Strike, an adventure module within the Dawn of Defiance RPG campaign. His character is also slated for a future appearance in The Gem of Alderaan, a later installment in the same campaign.