The Vurians were an alien civilization native to the planet Viga III, located somewhere in the Alpha or Beta Quadrants of the galaxy. This species went extinct in the 22nd century. (TOS video game: Judgment Rites)
The Vurians had four arms and roughly humanoid body shape, with minor psionic talents. White-skinned, this species had both male as well as female genders. A certain gas mixture was capable of knocking a Vurian out without harming it but required large quantities of it to be used for it to be effective.
The Vurians were believed to have been extinct by the 23rd century, with Federation historians speculating they died out by the time Zefram Cochrane developed the warp drive. The date of the extermination, a military action by the Antoshi in the Three Systems War, was probably during the early 22nd century. After their supposed extinction, it was noted that no one had seen a Vurian for around 150 years prior to 2269, though knowledge of their biology was known to doctors. What was not known to many was that the last known Vurian, Emminata, attempted to escape from her attackers and slingshot into the Antares sector where she was lost in the Antares Rift and transported into a parallel universe. Once there, she was cared for and telepathically linked to the Savant.
In the 2260s, when the starship USS Enterprise was exploring the Antares Rift, the ship was disabled and boarded by this Vurian, who kidnapped Science Officer Spock at the bidding of the Savant. Emminata had taken control of the auxiliary control room on the vessel, which prompted Captain James T. Kirk to attempt to knock it out with a gas mixture introduced into the ship the vents. However, when the crew arrived in the room once more, the Vurian seemingly teleported away and vanished inside a Rift where it was transported into another dimension. (TOS video game: Judgment Rites "Voids")