Many legendary creatures are seen in both Endless Ocean games. There are only two in the first game, but there are more in the second game. In Endless Ocean 2, they can be found in the Other Fauna section of the Marine Encyclopedia. You can tell which ones are legendary as they have no scientific name. This rule comes with the exception of a few, which have the same scientific names as the creatures they're based off of. They cannot be placed in the aquarium (except the Ancient Mother in the first game, after completing your encyclopedia) and your tour guide clients cannot see them, as they disappear during guided tours in both Endless Ocean games.
Big Bobby- A huge, man-sized Emperor Penguin with brown feathers, first encountered during a mission and afterwards found on the A-4 shore area in the Weddell Sea. He disappears temporarily when snowstorms occur.
Anomalocaris- A prehistoric Arthropod, seen swimming outside of Valka Castle's windows, where it can't be focused on. The first time you see it, you get both its info and trivia.
Cameroceras- A prehistoric orthocone (or "straight-shelled nautiloid") cephalopod, seen outside Zahhab Region, where it can't be focused on. The first time you see this creature, both its information and trivia are added to your encyclopedia.
Sea Serpent- What is thought to be a prehistoric plesiosaur, seen outside or Ciceros Strait at the South Canyon, where it can't be focused on. Similarly to the Cameroceras and Anomalocaris, you receive all of the information on this creature the first time you see it.
Several players have criticized the legendary creatures in both games because they are often simple resizes and/or alternate colors of normal animals. Others have noted that they bring an extreme lack of realism to an otherwise scientifically accurate game. In the first game, there was a large criticism in the fact that Legendary Creatures could be placed in the aquarium, but only after you had completed your marine encyclopedia in its entirety, with all of each creature's information.