Zorn

No one knows what a Zorn really is. But everyone knows, what it isn't. It isn't like any other creature in Britannia. Zorns seem to defy the very laws of nature and logic. Some say, they are the antithesis of everything. They simply walk through walls as if they weren't there. They negate all magic around them. And they disappear, should they be slain. The Zorn is a horrible foe, to be avoided at any cost.

Thankfully, they can be only found in the deepest dungeons.

Zorns only appeared in Ultima I and IV, it is unknown what happened to them after that. One can assume they were wiped out of existence by the cataclysm that created the Underworld.

Lore
''Little is known of the mysterious Zorn. `Tis a creature that not only defies logic, but that seems to defy the very Laws of nature. It can burrow through anything and is completely omnivorous. In battle it seems to generate far more force than one would estimate possible from a creature of its size. When slain, the Zorn quickly evaporates, thus none have ever been studied closely.''

- from "The First Age of Darkness", Ultima I

''Zorns are the antithesis of everything. They pass right through walls and obstacles, and negate all nearby magic. If an evil Zorn closes with thee, thou probably will not escape its embrace.''

- from "The History of Britannia", Ultima IV