Zak

Mad Zak is one of the inhabitants of the Abyss colony whose mind broke under the horrible conditions in which he was forced to exist.

When the Avatar found Zak on the third level of the Abyss in Ultima Underworld I, he had developed an almost lethal fear of the darkness and obsessively collected light sources like to keep the darkness at bay. At first, Zak wasn't of much use. Later however the Avatar learned that Zak had stolen the Taper of Sacrifice from the Knights of the Crux Ansata. So returning to Zak, he offered the hungry man some fish in exchange for the Taper, getting the Talisman through this deal. After hearing from Delanrey that Zak had her candelabra, the Avatar told of having meeting Zak and relayed his location to her.

Most likely Garamon rescued him when he teleported everyone out of the doomed colony.

Trivia

 * In the Ultima Underworld I Clue Book, Tyball admits that it was him who had implanted this fear of darkness into Zak.