Ness Creatures

The Ness Creatures 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. With the destruction of Exodus, the Ness Creatures were destroyed as well, ending their threat.

They were found, as said, in the ocean.

The Ness Creatures only appeared in the Age of Darkness trilogy, from Ultima I to Ultima III. In all three installments, mostly due to technical limitations, they didn't change at all.