R'Kgg of Regulus III was a male Regulun Federation ambassador in the 23rd century. In 2273, he accompanied the USS Enterprise to the planet Thallus, as that world was opening diplomatic negotiations with the Federation. While en route, the Enterprise received new coordinates, unaware that they were being sent by a Klingon space station. As the ship approached its destination, it was boarded by manifestations of horror movie monsters, one of whom, Count Dracula, murdered R'kgg. (TOS comic: "The Haunting of Thallus!")
- According to the TOS short story "The Blaze of Glory" Regulus III and most of the other Regulan Worlds were inhabited by Humans of Egyptian descent. R'Kgg might represent a Regulan reptilian, but these were, according to The Worlds of the Federation, native to Regulus II. This, however, still could be sufficiently explained by possible population exchange among the Regulan worlds. The original native race of Regulus III was the Veliki, but they supposedly lived approximately thirty millennia ago, though it is not definitely stated they went extinct. If not R'Kgg might be a Veliki or their descendant.
- (ST reference: The Worlds of the Federation, TOS - Star Trek II Short Stories short story: "The Blaze of Glory")