The Great Leviathan was a creature native to Tor.
Incredibly large creatures that announced their arrival hours ahead through the hooting and wailing of their slow, mournful song. They were fed on by other creatures like the Scythefish and cloudfish eating through mountain of flesh. The leviathans were too vast to be troubled by this. They traveled the ocean floors with their great trawler of a mouth scraping for food.
- Endless Space (2012)