Ironwit, from Ultima Underworld
The Avatar found him in Ultima Underworld I in the second level of the Abyss. Ironwit told the Avatar that he was the engineer of the Mountain-Folk in the Abyss, although he seemed a little crazy. He asked the Avatar for help, since he'd forgotten his blueprints in a room that was hard to reach and he'd lost the key, giving the Avatar a flying potion to reach the door, which was way up.
After the Avatar had managed to get the blueprints, Ironwit gave the Avatar another flying potion as a reward. Later, like the others, he was rescued by Garamon, when the volcano erupted.