Penser

 was a member of a long-lived species that sold stories to the very rich of the universe. He was one of the Overseers.

When the Sixth Doctor learned that this species was selling stories of his life and arrived on the planet, he met with Penser. Penser wasn't afraid of the Doctor and told him that they had a machine that could alter reality to make the stories more miserable and depraved. If the Doctor agreed to help them, they wouldn't use the machine to alter the events of his life. (PROSE: Telling Tales)