A scientist from Earth's Eugenics Wars who survives through clones and kidnaps Spock to create a giant clone peacekeeper in The Infinite Vulcan.
Dr. Stavos Keniclius is a human scientist from the era of Earth's Eugenics Wars who came to the planet Phylos, inadvertently bringing a disease that nearly wiped out the plant-like Phylosians. He has survived across the centuries by transferring his mind into successively improved clones of himself.
In The Infinite Vulcan, his fifth clone, Keniclius 5, kidnaps Spock in order to create a giant clone of him to enforce peace across the galaxy. Kirk convinces Keniclius that his plan is unnecessary, and he remains on Phylos with the giant Spock clone to help the Phylosians rebuild.