Return of the Mammalians

Return of the Mammalians is a single-player game mode in Splatoon 3. It involves the player donning a Hero Suit and venturing to the Alterna where the story takes place to defeat the Octarian army.

Story
An Inkling with their smallfry partner, little buddy, are scrap hunters who search for junk gems by day and splat it up in Turf Wars on the side. This Inkling met the New Squidbeak Splatoon and is now their new Agent 3 in the continued fight against the evil Octarians. It seems like the Octarian Army is planning an invasion of the squid world.