Rocs

Rocs are gargantuan birds which featured in Terran cryptozoology and myth. It is unknown if they ever existed in Sosaria. While a picture of one features in the Apple II manual for the original Ultima I release, these beings never appear in the course of the game.

Description
According to Earth accounts of the creature, the roc is a bird of prey (usually white) which is said to be large enough to swoop down and carry off animals as large as elephants. Famed Terran explorer Marco Polo alleges to have seen such creatures on his voyages, and describes their feathers as being up to twelve paces in length. While the roc's history on Earth as a cryptid has been explained by the presence of extinct giant extinct avians or simple embellishments in storytelling, the creature's existence in Sosaria or Britannia is almost entirely undocumented.

Such animals, if they ever existed, were never referred to in Sosaria after the First Age of Darkness closed with the death of Mondain.