Salmonids
A tide-driven warrior culture of evolved fish who surge onto the coast to spawn, guard their Golden Eggs fiercely, and are the enemy in Salmon Run.
Members
Salmonids evolved after the flood like the cephalopods did, but they never left the sea for good. They live in the ocean, spawn in enormous numbers, and periodically surge onto the coast in runs, and the Sunken Scrolls of Splatoon 2 describe them as a martial, hierarchical culture with ceremonial weapons, traditions, and a deep grievance against the land-dwellers who interfere with their nurseries.
The life cycle is visible in every Salmon Run wave. Smallfry are the swarming young. Chum are the standard adults, armed with frying pans. Cohocks are the heavy veterans. Above them stand the Boss Salmonids, specialized elders and war-machine pilots like the Steelhead, Stinger, and Flyfish, who carry the precious Golden Eggs. Splatoon 3 added the King Salmonids, Cohozuna, Horrorboros, and Megalodontia, as tide-ending catastrophes. It is implied that Salmonids grow through these stages, and that the bosses are the ones who survived.
Grizzco Industries exists to steal their eggs, and the Salmonids fight back with everything they have. Splatoon 3 complicated the picture by giving the new Agent 3 a Smallfry companion, Little Buddy, who proves loyal, brave, and, when fed Mr. Grizz's fuzz, enormous. If one Salmonid can be a friend, the games quietly ask, what does that make every Salmon Run shift? The Salmonids keep coming with the tide, and they have not answered.