Kayron was a Ferengi crewman who served under DaiMon Tarr aboard his marauder in 2364.
That year, he was aboard when Tarr participated in the theft of a T-9 energy converter from Gamma Tauri IV.
Following that incident Kayron was part of the Ferengi science team that beamed down to a planet in the Delphi Ardu system when their starship was immobilized above the planet by a powerful force field. He and the rest of his away team attacked Riker and his away team, but were stopped by the Portal, a guardian of the Tkon Empire. He and the other Ferengi attempted to blame the Federation away team for the violence. (TNG: "The Last Outpost")
Kayron was part of Commander Riker's memories while being infected on the surface of Surata IV and treated in sickbay. (TNG: "Shades of Gray")