Submariner — Sea Life

The Barbed Tremorfish is one of the first warning signs that a voyage has crossed from open water into hunted water. Its plated skull is riddled with pressure-sensing pits that let it hear the faintest shudder of a submarine hull, even through silt, engine noise, and black current. When agitated, the Tremorfish curls its body tight and releases a violent pulse through the water before striking. The impact is rarely enough to sink a vessel outright, but its hooked dorsal barbs scrape across armor seams and leave the hull weaker for whatever answers the noise next. Submariner crews call them "knockers" because they often announce themselves with three dull impacts against the outer plating. By the time the fourth knock comes, the fish is usually close enough for the teeth to matter.