Eymorg starship
The Eymorg starship was a highly advanced starship operated by the Eymorg of Sigma Draconis VI during the mid-23rd century. 

This vessel was constructed from a unique technology, with an origin potentially dating back as far as 8000 BC. It was capable of high velocities, as it was driven by an ion propulsion drive. The vessel also possessed transporter capabilities, and could be operated by a crew of one.

In 2268, the  encountered an unidentified Eymorg starship outside of the Sigma Draconis system. The ship, according to Montgomery Scott, was unlike anything he had seen, stating that its owners "could teach us a thing or two." The vessel, piloted by , leader of the Eymorgs, was sent to the Enterprise to retrieve a brain to serve their new Controller. 

After stunning the Enterprises crew, Kara removed Spock's brain and left the Enterprise aboard her vessel, whose ion trail was later used by the Enterprises sensors to track its final destination. ()

Background information 

The revised final draft for the script of "Spock's Brain" described the vessel as "Long, slender, needlelike, alien, almost glowing in the blackness of space." 

For the  remastered version of "Spock's Brain", a new computer-generated version of the ion-powered spacecraft was rendered by CBS Digital. The new ship featured a completely overhauled designed which abandoned the now antiquated notion of a rocket-shaped vessel. 

The CBS description of the model stated:
"In the episode "Spock's Brain" the ion propulsion spacecraft spotted by the Enterprise in 2268 certainly impressed Scotty with its design and technology. The comparison between the original and the remastered version provides two totally different looks, with styles defined more by the contemporary technology. The original is a standard rocket-shaped configuration. At the time, "spaceships" tended to fall into a one of two classic looks, the other being the flying saucer.The new, remastered version of the ion propulsion craft is smaller and more utilitarian, reflecting its single-person occupancy, and it ditches the unnecessary missile/rocket configuration. The design also reflects more modern-day ion propulsion prototypes." 

de:Eymorg-Raumschiff
Starship classes
Retconned material in background