Vernix, from Ultima Underworld
When the Avatar met him on the first level of the Abyss in Ultima Underworld I, the hero had to constantly stroke Vernixs' ego in order to get information out of him and preventing him from cancelling the audience. The Avatar's self-abasement was worth it, as Vernix had a lot of information.
Vernix knew of Sir Cabirus and the eight talismans, the Knights of the Crux Ansata, the Seers of the Moonstone, his feud with the grey Goblins, and the Lizard Men and their language problems. When the Avatar then bid farewell, Vernix asked if the Avatar could murder the king of the grey Goblins when meeting him.