SkekTek is the Skeksis Scientist. He plays an important part in the story, since it is his job to drain captured Podlings and Gelflings of their life essence in his laboratory, the Chamber of Life. This process turns the victims into slaves which perform the work at the Skeksis castle. It has also been stated that the Scientist altered the slaves' vocal cords to fit them for the castle choir.
SkekTek later met his death when the animals in his laboratory retaliated with the help of Kira, pushing him into the shaft of the Dark Crystal, where he fell to his death. Sadly, this death also killed urTih.
Steve Whitmire later used a voice similar to SkekTek's for Marlon Fraggle.
In pre-production notes for the film, skekTek, who was also called the Doctor, is "identified by his self-mutilated body, especially an artificial leg and bionic arm. His pale, pink-white neck is held in place by a brace with metal bits, and his body is fed through chrome and plastic tubes. One eye is fitted with a telescopic eyepiece."
“To betray is to break the circle of trust. The Skeksis came to betray all friendship, without reason, without need. The end of my friendship with skekTek the Scientist is still bitter. Before the division, TekTih of all urSkeks gave me most; then his divided soul became Alchemist and Scientist alike. When the urSkeks first came to the World he taught (Aughra) all the movements of the skies and designed the great Observatory. And in return (she) gave him all (her) knowledge of the rocks, even to the secrets of the metals.
SkekTek kept some real power of thought, but in truth he had become only a juggler of ideas, of memories from his previous life. Then he had studied the light of the Crystal and used it for the division; now he studied the wounded Crystal, and by that light he saw his ways to acts of darkness. Two great evils I charge against him. First, that he learned the art to make beams of light from the Dark Crystal, which he burned into Pod People's eyes to make them living ghosts, his perfect slaves. After the light had struck them no light lived in their eyes, but they obeyed; that was all.
And the second worse evil was to use dark light to draw the essence of life, to drain it from the living to make a drink for the Skeksis, above all for the Emperor. This essence gave them back their youth and vigor for a while, only for a little; but many Gelflings were victims forever.”
—The World of the Dark Crystal