Zorn

Zorns are a bizarre breed of magical creature seen briefly in Sosaria and later in Britannia. Known as "the antithesis of everything," they are capable of a number of unexplainable behaviors. Zorns appear in Ultima I and  IV.

Description
Zorn bodies consist of a large semi-spherical node supported by three legs. Their mouths are situated on the top of this node, whereas their sensory organs are positioned close to the ground. Through means unclear, zorns are capable of physically transcending all known matter, passing through obstacles as though they do not exist. This strange negation of reality also appears to affect the ethereal waves surrounding these beasts, as magical arts are disabled in the immediate vicinity of zorns. Commonly found in subterranean locales, these polyphagous entities have long puzzled scholars, as the evaporation of their physical bodies upon death has left little means of studying the zorn. They have occasionally been found in the company of the normally xenophobic gazers, although their purpose in this seeming alliance has never been discovered.

Zorns faded from human sight shortly after the completion of the Quest of the Avatar, but whether this vanishing was due to extinction, migration, or other causes has never been determined.

Trivia

 * Zorns are derived from the xorn of the tabletop role-playing game,  Dungeons & Dragons. These creatures first appear in the original 1977 edition of Monster Manual, a bestiary published for the game, and closely resemble their counterparts in Ultima, possessing a similar trilateral radial symmetry to their form and a capability to move at will through stone and minerals. Both zorn and xorn furthermore are said bear a likeness to the three-limbed  Asag, a Sumerian demon that features in the poem Lugale.
 * Zorns were to be included in the canceled Ultima X, where they appeared to have adopted the geophagic behaviors of the Dungeons & Dragons xorn (see Planned Monsters for Ultima X).