Ruk
Ruk was an android built on Exo III half a million years before the 23rd century by the . 

Ruk was tall, broad and immensely strong, capable of lifting a Human male easily with one hand. Despite his size, he could move silently and gracefully, making him an extremely dangerous physical opponent. He could duplicate voices effortlessly – his actual voice was very low-pitched and gravelly. 

He was discovered in the underground ruins of that planet in 2261, by Dr. Roger Korby, where he was still tending the machinery the Old Ones had left behind. Even he did not remember how many centuries he had been doing this work. Ruk helped Korby learn how to use the ancient machinery, including the android duplicator. With Ruk's help, Korby built other androids, including  and Andrea.

In 2266, Captain James T. Kirk and Christine Chapel arrived at Exo III in search of Korby. By then, Korby had reprogrammed Ruk to serve him, and had devised a scheme to infiltrate android duplicates into society slowly and carefully. As part of that scheme, Korby and Ruk imprisoned Kirk and Chapel, and built a  to take control of the .

Questioned about his origins by Kirk, Ruk remembered that the androids, presumably including himself, had become frustrated by the illogic and inferiority of the Old Ones. In turn, the Old Ones became frightened of their creations, and began turning them off. Their survival at stake, the androids overcame their programming and slew their makers. Once Ruk remembered this, he overcame Korby's programming the same way. No longer able to control Ruk, Korby destroyed him. ()

In 2381, a framed photograph of Ruk was among several others displayed on the walls of a bar on Starbase 25. ()

Appendices

Background information
Ruk was portrayed by Ted Cassidy. Additional voices mimicked by Ruk were provided by Majel Barrett, William Shatner, Michael Strong, and Sherry Jackson.

In the revised final draft script of "What Are Little Girls Made Of?", Ruk was characterized as a "huge, enormously tall, completely hairless half-Human creature." He was also scripted to have a "heavy" voice. 

The book Star Trek: The Original Series 365 (p. 066) refers to Ruk as "a monster right out of the classic novel ." Ruk's facial appearance involved makeup designed by TOS Makeup Artist Fred Phillips. He emphasized the natural planes of Ted Cassidy's face with grease pencil and covered the actor's hair with a latex bald cap. The costume Cassidy wore as Ruk was designed by TOS Costume Designer William Ware Theiss. (The Star Trek Compendium, 4th ed., p. 41)

According to the novella "", the mirror universe  of the  destroyed the last surviving member of the android society (presumably Ruk's mirror counterpart) on Exo III, who had likewise turned on their masters and killed them.

External links

de:Ruk
Androids