Orcs

Primitive, porcine humanoids created by magical experiments in the Age of Darkness, Orcs are not particularly strong or intelligent, but always travel in packs. Their life goals are simple: plundering, killing, and reproducing. Usually little more than pests, they are typically encountered in the wilderness, but frequently dwell underground as well.

Orcs never changed much in the games they appeared in, being primitive roadside-robbers that were barely a threat to veteran adventurers. In Ultima III their connnection to the physical world was still fragile enough that the simplest magic could dispell them -- a weakness they shared with their cousins, Goblins and Trolls. After Ultima V, they apparently became extinct.

Trivia

 * Along with Elves, Orcs were scheduled to make a reappearance in the cancelled Ultima X. Their detailed historical write-up is interesting, but not necessarily canonical. It can be read here.