Murgo, from Ultima Underworld
When the Avatar met Dr. Owl on the sixth level of the Abyss, he revealed that he knew where to find the Wine of Compassion, but would only reveal it should the Avatar manage to safely return his missing assistant Murgo.
The Avatar found the mute man in the prison of the Lizard Men on the third level, imprisoned for food theft. The hero first had to give the starving man some food before he'd be of any help. Murgo helped the Avatar by teaching the Lizard Man language, a task made difficult since he communicated only through gestures, so that the Avatar could convince the jailer Sseetharee to set Murgo free to return to the mages on the sixth level.
Dr. Owl kept his word, and revealed the location of the Wine of Compassion.
- It is important to learn the language from Murgo before setting him free, since he'll never be seen again.