Orcs

Primitive, ape-like humanoids, created by magical experiments in the Age of Darkness. They are weak, but always travel in packs. Their life goals are simple: plundering, killing, reproducing. They are a pest. Thankfully, they become extinct after the time of the Shadowlords.

They are typically encountered in the wilderness, but dwell underground as well.

Orcs never changed much in the games they appeared in, being primitive roadside-robbers of not much danger at all. In Ultima III their connnection to this world was still fragile enough that they could be dispelled - a weakness they shared with their cousins, goblins and trolls. After Ultima V, they 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.