Mentor First was the largest Mentor of planet Jamya, and the one in charge. Thirty thousand years after activation, he was the only Mentor left functioning. Even then, he was not in a state of mental stability, and the palace computers were programmed to deactivate him if he became too dangerous.
When Norby and Jeff Wells first revisited Jamya, Mentor First forced them to undergo a mind probe, and discovered Norby’s origins before they escaped. When they came back with Fargo Wells and Oola, he recognized the All-Purpose Pet he had designed for the Others, so long ago. Mentor First began to become sane once more, and explained everything to his new friends.
His “son,” Norby, took him into Zero-space to refuel, and bring back energy for the other Mentors. He and Norby found the Others’ supply ship on an asteroid, but had to fight off pirates to get it. Mentor First was distressed that Norby chose to stay with Jeff, and for a time kept Jeff's brother Fargo to get him as ransom, but eventually accepted it and enjoys his frequent visits.