Traveler

Travelers are a race of people from the planet Tau Alpha C. The Travelers make up just 1% of the total population of the planet, but the possess extraordinary powers that enable them to control time and space.

If a Traveler encountered another being that they became impressed by, then the Traveler would act as a mentor to the being until they are ready to be "born" as a Traveler.

(TNG novel: A Time to Be Born).