Ness Creatures

The Ness Creatures (or "sea monsters") were the bane of all seamen. Found in lakes and oceans, it was a serious threat to shipping whenever it is encountered. The existence of these creatures was eventually verified when one sank the frigate Pembroke in full view of an armada. These creatures disappeared after the destruction of Minax, replaced by the even more terrifying sea serpents - waterborne dragons.

They were found, as said, in the ocean.

The ness creatures only appeared in the Age of Darkness, in Ultima I and Ultima II, changing little between the two installments other than the renaming in II.