Bork
Bork was a Tellarite and the engineer on the [SS Clydesdale]], commanded by Mike Harper. Like Mike, Bork worked for Gravit & Yurtz, but when Mike bought the ship from their employer, Bork asked to stay on.
As is true of most Tellarites, Bork is gruff, but in addition to his insults, he tends to break into long lectures about whatever is bothering him. Prior to working for Gravit & Yurtz, Bork was engaged to Annar, owner of Annar's Exports. When the relationship ended, he went to work for her rival. Bork was convinced to see her again when Mike needed a cargo shipping job to Antares. Annar gave them the contract on the condition that the Clydesdale also transport her nephew, Duv. Duv was not happy to be around Bork, whom he blamed for breaking his aunt's heart when the engagement ended. After the Clydesdale was intercepted by the USS Ventus and most of its crew put in the brig, Duv laid into Bork about Annar, at which point Bork revealed that Annar had been the one to end the relationship. Duv realized this was the truth and softened toward Bork. ("Antares or Bust," "Busted" [TOS])