GNMA-04B11 Trilobite

A GN-Drive Tau-equipped mobile armor for underwater combat that first appeared in episode 4 of season 2. It requires two pilots instead of one and was destroyed by Setsuna's 00 Gundam in only a matter of seconds with the 00's GN-Advanced Swords II. The unit can also fire torpedoes which can pierce through a GN-Field and equipped with 4 Grappler Claws. It's unclear if this was a mass production model or a prototype.