The Chambered Nautilus, called the Emperor Nautilus in the European releases of the games, is a small cephalopod found in deep-sea or enclosed areas.
"Its spiral shell has a radial pattern of red-tinted brown lines. It has so-called pinhole eyes, which have no lens and leave it with poor eyesight. Its ancestors lived about five hundred million years ago, when ammonites and other large species thrived. However, their numbers fell due to subsequent climate change, natural selection, and other factors, and only the Nautilidae family survived to the present day."
These small creatures float around slowly and aimlessly. They like being fed.
- The fictional character Captain Nemo from the novel 20000 Leagues Under the Sea (by Jules Verne) named his submarine, the Nautilus, after this creature.
- The name "Chambered Nautilus" comes from the fact that these creatures make their shells larger as they grow, adding compartments behind them in the unused portions of the shell, the 'chambers' the name refers to.
- Another common name for this creature is the Pearly Nautilus.
- A distant relative of this creature, one that went extinct long before humans ever existed, is the Cameroceras, which makes an appearance in Endless Ocean 2.