Quetzalcoatl was a member of benevolent seemingly omnipotent beings. His race owed its powers to a special gland at the top of their spine. Their powers included immortality, teleportation, telepresence and power over life and death.
He and his 'brothers' traveled to worlds preaching peace and teaching them how to evolve. However they were often disappointed on how their messages were misunderstood and distorted in the process of time.
Quetzecoatl visited Earth several thousand years ago and interacted with a Native American tribe in what would later become Mexico. This tribe, the Aztecs, came to worship Quetzalcoatl as a god following his departure. While Quetzalcoatl had originally preached a message of peace to the tribe, the Aztecs used Quetzalcoatl to justify sacrificing a large number of humans over the years.
After departing Earth, Quetzalcoatl eventually came to the Klingon world of Hrakkour IV sometime before the 23rd century where he presented himself as a Klingon named K'etz'koatl. Preaching a message of peace, Quetzalcoatl convinced the Klingon colonists to adopt a more peaceful outlook on life and then retreated to the planet Zamphor.
In response, angered with how his subjects' turned themselves away from the Klingon traditions and code of honor, Admiral Vlict Kenka committed genocide, killing all the colonists on Hrakkour. Feeling that his actions would be too brutal for even the Klingon code, Kenka used Quetzalcoatl as a scapegoat for the genocide on Hrakkour.
In around 2270 (stardate 5097.03), the USS Enterprise followed the Klingon military activities and offered to help them apprehend the 'criminal'. They encountered Quetzalcoatl on Zamphor. Quetzalcoatl initially refused to believe Captain James T. Kirk when he was told of the Aztec violent culture after his departure, and subjected Kirk and his landing party to several trials. Quetzalcoatl was impressed to see that Kirk and the landing party solved these trials without resorting to violence, and reconsidered what Kirk had told him at their initial meeting.
Being disappointed of his own work and his failures, Quetzalcoatl asked Doctor Leonard McCoy to remove his essential gland. Quetzalcoatl and the party were transported on the Enterprise and McCoy surgically removed the gland, turning him into a mortal in the process.
Since it was a Klingon internal matter, the Organians compelled the Federation to bring Quetzalcoatl to Hrakkour for trial, and Admiral Kenka attempted to have Quetzalcoatl executed. As he claimed, Quetzalcoatl had no honor to deserve trial by the Klingon High Court. Kirk talked in his defense claiming his identity as a honorable warrior. Kenka then sent Kirk's team in the ancient pits of Bialbi below the planet's surface.
While Kirk's team were making their way out, an advanced being known as Bialbi intervened and brought Kenka alone in front of Kirk to judge him for the evil inflicted on the world and Quetzalcoatl. Bialbi would have executed Kenka, but Captain Kirk intervened and Bialbi relented - ordering Kenka to leave Hrakkour and never return on pain of death. Following this, the Enterprise returned Quetzalcoatl to his home. (TOS video game: Star Trek: 25th Anniversary)
- In the less than perfect situation of the game, it is possible for the player to abandon his defense in the trial, or simply fail to respond appropriately to the accusations. In that case, Quetzalcoatl accepts the condemnation and submits to the decision to be executed.
- In the CD-ROM version of the game, Quetzalcoatl is voiced by Jeffrey Winkless.