Kol was a Ferengi stranded in the Delta Quadrant with Arridor after they ignored a warning about the unstable Barzan wormhole.
Kol was a member of the Ferengi delegation that tried to win the rights to the Barzan wormhole in The Price. When a Federation shuttle went through the wormhole to test it, the Ferengi sent their own pod, with Kol and Arridor on board, to keep pace with Data and La Forge.
The Starfleet officers realised that the far end of the wormhole was unstable and warned the Ferengi to return, but Kol and Arridor refused to listen. The wormhole's exit moved, stranding the pair in the Delta Quadrant with no way home.
The two later reappeared in Voyager, having made themselves into gods on a primitive world they exploited for profit. This Kol is a different person from the Klingon Kol of the House of Kor.