A man born thousands of years ago in Mesopotamia who never aged, and who lived through history under many famous identities.
Flint lives in seclusion on the planet Holberg 917G, surrounded by art and artefacts. When the Enterprise arrives seeking a cure for a deadly fever, he reveals that he was born in ancient Mesopotamia and has lived for thousands of years, claiming to have been figures such as Leonardo da Vinci and Johannes Brahms.
Flint built the android Rayna Kapec as a companion and arranged for Kirk to awaken her emotions, but the conflict between her feelings for both men destroys her. McCoy then discovers that Flint, having left Earth, has lost his immortality and will now age and die like any other man. He was played by James Daly.