Ghouls

Ghouls (also called Zombies) are magically animated corpses of the recently dead, similar to animate skeletons save that flesh still clings to their bones and the plagues of the grave may often be spread by their bite. They have appeared in Ultima III,  VIII and  IX

Ghouls of Sosaria and Britannia
These creatures once roamed the ancient lands of Sosaria during the time of Exodus, where they could often be found in league with their brethren undead. These mindless corpses were but a modest danger to a well-equipped company, and those fortunate enough to travel in the company of a one of the Cult of Truth would find that such beasts could be slain readily by the Clerical enchantment Pontori. Such enfleshed undead grew less common as the newly christened Britannia entered its Age of Enlightenment, although Philpop the Weary still made mention of such creatures in his  Book of Mystic Wisdom.

Centuries after seemingly fading from the realm, these animate corpses reappeared in the last years of the Age of Armageddon, returning to plague Britannia's living in the last days of the Avatar's adventures in the land. These beings were plagued with an insatiable curiosity and a vicious appetite for the flesh of men. Until the final destruction of their bodies, such zombies' limbs would reach ever toward their intended prey, even when severed. Their bite, polluted with the pestilence of death, could also induce sickness and even death in those who received it.

Ghouls of Pagan
The ghouls of Pagan were all bound into the service of the elemental Titan of Earth, Lithos, the Mountain King. These undying servitors could frequently be found lumbering about the Cemetery and Catacombs of Morgaelin. Their duties to Lithos were largely ceremonial, as their wretched state left them wracked with pain and slow to move. However, should trespassers venture too near to the Mountain King's domains, these wretches would do their best to drive them back alongside their skeletal brethren, relying on their plague-inflicting bite to deter those who would tread too near.

Trivia

 * Ghouls and zombies were to be included in the canceled Ultima X. See Planned Monsters for Ultima X: Ghoul and Planned Monsters for Ultima X: Zombie for further details.
 * Another variation of Ghouls would have appeared in the cancelled add-on, The Lost Vale. Undead legion of Hydros would have resembled corpses which had been preserved underwater for a very long time.