The Unified Dray Peoples were an interstellar political entity in the galaxy's Alpha or Beta Quadrants. However, by the time of the Federation, the Dray had long since vanished and were only known through mythological records.
History and specifics[]
At least 150,000 years ago, an all-consuming war between the Unified Dray Peoples and the Nax Empire led to the extinction of both sides.
By the 23rd century, the only known surviving relic of the Dray was Red Worm, a super dreadnought whose AI continued to operate the vessel in the absence of personnel on the outskirts of the galaxy. (TOS audiobook: A Mirror for Futility)