Unagi The Eel

Unagi the Eel is a maroon eel that appears in Jolly Roger Bay. In the first mission, they stay inside of the ship before eventually leaving and swimming around. However, in the next missions, it stays inside a tunnel, though eventually leaves the tunnel and later re-enters the tunnel. It deals damage upon contact, and is invincible.

Dire, Dire Docks Manifestation
several reports state that Unagi can appear in Dire, Dire Docks, usually in the whirlpool seen in the first part of the level.