It was later revealed to Kirk and McCoy that the commandant was part of the Khitomer conspiracy and was ordered by GeneralChang to allow them to make an escape attempt so they would appear to have been killed while trying to escape. The commandant captured them escaping as planned, and was about to tell them who wanted them killed before executing them, when they were beamed aboard the USS Enterprise-A.
In the various instances of creating his designs, makeup artist Richard Snell often took it upon himself to establish a backstory for his creations, as he often found the actor fulfilling the role inquiring about why the character's look is a certain way. In this instance the backstory he created for the commandant's was "–you're basically no good anymore to [the Empire] as a true fighter, maybe as a strategist. Now you have this horrible disfiguring scar and even though it's debilitating, you're making it work for you. We're going to make it ooze a little and you're going to use it over your prisoners as a psychological tool because you're using your mind." Snell continues, "I went into a great deal of character development for all the characters I did. The commandant is a little Napoleon. He rules with an iron fist. But in Klingon life, small people don't usually get ahead. Klingons are a huge race, particularly the ones that were used on the ice planet. We used even bigger than normal Klingons; these were the baddest of the bad. These were the guards at the worst prison in the galaxy, holding onto prisoners that were alien and all sort of different capabilities. They were absolutely gigantic, yet their commandant was half their size. How did a man like that get to be in that kind of power and respect given their background? So in terms of makeup, we put a huge scar through his eye and blended off the prosthetic down below the eye. It's a dead eye oozing stuff, and it's just kind of creepy to look at. In my mind, this character knows it. He knows that's it's difficult to look at an eye that has seepage and he puts it right in your face as a psychological tool." (Charting the Undiscovered Country: The Making of Trek VI, p. 92-93)
This Klingon was a prison guard at Rura Penthe in 2152. He used a pain stick on Kolos. Archer attacked him and used the pain stick on him. After subduing Archer, he threatened to have Archer spend the night on the surface where no one survives. (ENT: "Judgment")
This alien was played by an uncredited Dennis Ott. His scene was cut from the version of the film aired for television.
To create the distinguishing changes in his skin color, "Ed French employed fluorescent makeup so ultraviolet light could trigger changes in coloration. This required the assistance of technicians from the Wildfire company," who used the same technique originally used for the Tarchannen III species in TNG: "Identity Crisis". "Nicholas Meyer learned the possibilities of the effects and suggested they increase the intensity of the ultraviolet light to communicate pain." It was also indicated that this was "an alien bully who has lost more fights than he's won" [...] as "was indicated by having the creature's horns look squashed." (Trek: The Unauthorized Story of the Movies, p. 176)
This prisoner was brought to the surface of Rura Penthe to demonstrate that no one could survive on the surface. He was barely clothed and frozen within minutes. The commandant told the arriving prisoners including James T. Kirk and Leonard McCoy that they should work well and they would be treated well and if they would work bad they would die. (Star Trek VI: The Undiscovered Country)
This prisoner froze to death on the surface of Rura Penthe, when he was brought to the surface as punishment in 2293. His corpse was seen by Kirk, McCoy and Maria when they escaped the prison camp. (Star Trek VI: The Undiscovered Country)
The frozen Klingon was a dummy made to resemble makeup artist Edward French. French attached a Klingon headpiece to his own head and made a cast of himself with a tortured expression on his face as the foundation the prisoner's appearance. (Cinefex 49, February 1992, p. 44)
In deleted scenes from Star Trek, Klingons captured the Narada after the USS Kelvin crashed into it and imprisoned Nero for the next twenty-five years. These Klingon guards wore helmets and thick coats, which costume designer Michael Kaplan respectively modeled on a horseshoe crab and elephant and rhino skin. J.J. Abrams said the masks allowed them to avoid selecting Klingons that did or did not have the augment virus. According to him and the producers on the audio commentary for the deleted scenes, the Klingons come up to Nero in large numbers and throw him a chain to cuff himself because they're actually scared of him.
In a deleted scene, an alien named "4-Square" (who was named because he had four eyes) had kept papers of Nero's plans in his cell and was interrogated by the guards after when they found them in his cell.