Marina - Octoling - Marina is one of two members of Off the Hook, a band featured in Splatoon 2, along with Pearl, that hosts their own television show, similar to the Squid Sisters from the first game.
Shiver - Octoling - Shiver is one of the three members of Deep Cut, along with her costars, Frye and Big Man.
Frye - Inkling - Frye is one of the three members of Deep Cut, along with her costars, Shiver and Big Man.
Big Man - Manta Ray - Big Man is one of the three members of Deep Cut, along with his costars, Shiver and Frye.
Cap'n Cuttlefish - Inkling - A war hero and leader of the Squidbeak Splatoon, he led the Inklings to victory over the Octarians 100 years ago. Now continues to monitor the Octarians in his old age and recruits new agents to stop their plans.
C.Q. Cumber - Sea Cucumber - A translucent blue sea cucumber wearing a train conductor's hat. He is the conductor of the Deepsea Metro.
Judd - Cat - A cat preserved in time, long after the extinction of humans. He plays the role of referee in multiplayer matches, and also gives battle advice outside the Battle Lobby.
Li'l Judd - Cat - A clone of Judd. He plays the role of co-referee alongside Judd.
Mr. Grizz - Unknown - The boss of Grizzco Industries. He speaks to his employees in Salmon Run through a fishing bear statue with a radio antenna attached to it. His true appearance remains unknown.
Iso Padre - Giant Isopod - A resident of the Deepsea Metro who wears sunglasses, a gold neck chain, and a black leisure suit and carries a briefcase filled with toys. He also carries several childish accessories to further emphasize his playful side. He collects mem cakes.
Jelonzo - Jellyfish - A jellyfish that owns the Jelly Fresh store. He is one of the few known jellyfish able to communicate with Inklings, albeit poorly, as his dialogue is rendered in broken English.
Annie - Sea Anemone - A sea anemone that owns the Cooler Heads store with a very shy personality. A clownfish named Moe lives in her tentacles. Due to getting too flustered greeting customers, she moves her shop online in Splatoon 2.
Moe - Clownfish - An abrasive clownfish that slings insults at the customers of Cooler Heads at any given opportunity. Despite acting tough, he never leaves the safety of Annie's head.
Sheldon - Horseshoe Crab - A horseshoe crab that runs the Ammo Knights shop in both Splatoon games. He is easily excited by the variety of weapons used in Turf War and is known to talk about them for a very long time. In Octo Canyon, he lends Agent 4 a variety of Hero weapons to use for specific levels.
Spyke - Sea Urchin - A sea urchin that works in the back alley of Inkopolis Plaza. He allows players to order the gear of other players, albeit often for higher prices. In Splatoon 2, he has retired after making money through a get-rich-quick scheme.
Bisk - Spider Crab - A spider crab that runs the Shella Fresh store and has a laidback personality. At one point, he broke up with his girlfriend to pursue a career in music.
Jelfonzo - Jellyfish - A jellyfish that owns Ye Olde Cloth Shoppe, and the son of Jelonzo. He is also capable of speaking to Inklings, but due to studying ancient texts, his speech is very antiquated. Despite this, he always stays up to date with the freshest styles.
Flow - Sea Slug - A sea slug that runs the Headspace store and has a very spacey and relaxed personality. Most Inklings seem to think of her as their "crazy aunt," and an emperor shrimp named Craymond lives on her head.
Craymond - Emperor Shrimp - An emperor shrimp that lives on top of Flow's head. He has a very quick and anxious personality, in contrast to Flow, and frequently blurts out words when Flow finishes talking.
Murch - Sea Urchin - A sea urchin that lets the player order others' gear and offers various other services to help players get the abilities they want. He is seen to look up to Spyke and appears to be following his get-rich-quick scheme.
The Octarians are the main antagonistic species of the story mode in Splatoon. They reside in Octo Valley, and are responsible for stealing Zapfish from Inkopolis. Their main ink color is dark fuchsia. The Octarians fought against the Inklings for territory in the Great Turf War and lost. Unlike Inklings, the species includes a great number of sub-species that act differently from each other. DJ Octavio is the leader of the Octarians in the single-player story modes Octo Valley and Octo Canyon.
Salmonids are a family of salmon and trout introduced in Splatoon 2'sSalmon Run. They reside far off the coast from Inkopolis on man-made islands called "Spawning Areas". Like Octarians, they have many different varieties. They are fought in Salmon Run as enemies, but in Splatoon 3, one becomes a helpful character.
The Telephone, also known as Commander Tartar, is the main antagonist of the Octo Expansion. It created the Sanitized Octarians by sterilizing them with primordial ooze.
Octolings are the Octarian equivalent to Inkling, being octopus-like humanoids. They serve the Octarian military, while many have left and integrated into Inkling society.
A species and type of currency in Splatoon and Splatoon 2. Their sole use is to increase the number of slots on gear or reroll all gear abilities on a select piece of gear.
Creatures that appear in Splatoon'sOcto Valley and Splatoon 2'sOcto Canyon modes. The player must rescue one at the end of every level in order to proceed in the story. To take the Zapfish, the player must burst its shield with ink, like the Rainmaker's shield. Then they must touch it and the screen and music will change to say that they have passed the level.
Sally and Hara Wataru, a pair of graffiti artists.
Marie mentions having a friend who is a Blackbelly Skate.
Marina mentions that one of her friends is a Sea Sponge.
A handful of animals are seen and/or heard at various locations, including seagulls, sparrows, cicadas, and crickets. Unlike other creatures in Splatoon, many of which have evolved into more human-like forms, these animals seem to have changed very little over time.
Shy-Ho-Shy, the Squid Sisters' producer. She was a judge at the Youth Folk-Singing Contest, where Callie and Marie's performance caught her attention, which led to her becoming their producer.[3]. She wrote City of Color, and created a demo of it, which is in Splatoon Live in Makuhari -Shiokalive-.[4]Splatune 2's booklet contains an interview with Marina which mentions that she has been in touch with Shy-Ho-Shy.