The Eater is a gigantic Ybian ship in the shape of a sea creature constructed during the Kiri-Sama War to defend Ybian space against possible human incursions during the course of the War. It was intended to warn ships off but also to have a stealth capability whereby it could appear inanimate and then quickly move in on ships and crush them in its "jaws." It had FTL capability via a ripple drive.
The Eater was never formally deployed. During its final construction and testing phase, it was stolen by an Ybian, Red Blue Low, and a human scientist, Decodo Fedec of the Sama Nation. These two individuals and the Eater were reported lost.