Dantes, from Ultima Underworld
The Avatar freed him from Tyball's prison on the seventh level of the Abyss in Ultima Underworld I. Dantes was concerned that without provisions, the Avatar would quickly die in this hell. However, when asked for help, Dantes revealed an escape route he'd once dug. A route that was useless for him, since it ended at the lava chasm and thanks to a bad leg he didn't dare to jump.
Later, Garamon rescued him when the volcano erupted.