Inkling

Inklings are a sentient race of squid-like humanoids who are the main protagonists in Splatoon.

Background
Inklings are evolved species of squid that came to be after rising sea levels sunk human civilization. Circa 2000 years before the events of Splatoon, the inklings crawled up to what little habitable land there was left on the planet. Because of this lack of suitable land, the Turf War was established. The original Turf Wars were judged by Judd, who was cryogenically frozen from the time of the humans. 100 years before the events of Splatoon, the Inklings and the Octarians engaged in a Great Turf War. A young Cap'n Cuttlefish and the Inklings won, forcing the Octarians to retreat into Octo Valley.

Appearance
Inkings can alternate between a humanoid form and a squid form. At the age of 14, Inklings gain complete control over both these forms and can change at will.

The squid form resembles a small, flat, monochromatic squid-like being with eight small tentacles in the middle, and two large ones on the sides, resembling the hair of their humanoid form. It has relatively large head fins, and two upward-facing, human-like gray eyes. The undersides of their enlarged calipers are always white, regardless of what color the rest of them is. In this form, they are largely incompetent outside of their own ink, but when swimming in it, they can completely submerge into it and swim at speeds almost four time their humanoid form. They can even jump out of the ink to cover further distances and swim up ink-covered walls. However, this form is also largely vulnerable, as being inside of enemy ink in this form will eventually kill an Inkling.

The humanoid form has a black marking for supposed "swim goggles" around its eyes, pointed ears, and "hair" that resembles a squid's tentacles that changes color according to their ink color. This color is randomly selected out of predetermined pairs that can be found in Sunken Scroll number seven. Their mouths contain human-like teeth, as well as three larger sharp teeth which resemble a squid's beak. Inklings have no bone structure, making their teeth possibly the only truly solid part of their body, as squids also have teeth.

Inklings are also customizable. If the player chooses a girl Inkling, their Inkling will have thin eyebrows and two long, strand-like tentacles that hang from both sides of the head, and four extremely short tentacles in the back. A boy inkling has noticeably larger eyebrows and two tentacles tied in a ponytail in the middle of the back of its head, tied together with a band, and four extremely short tentacles on the back of the head like the Inkling girl. Each inkling has six hair-like tentacles, along with four others as their arms and legs. Skin color, gender, and eye color can be changed in the options menu at any time. Head accessories, shirts, shoes, and weapons can be changed to the player's liking in the equip menu. Many clothing items change to match the Inkling's current color. Both forms have a slightly different pitch to their voice.

Abilities
Both of the Inklings' forms have abilities associated with them. In humanoid form, Inklings can splatter a special type of colored ink by using various weapons, such as a gun that resembles a Super Soaker water gun. This ink can be quickly spread over many surfaces, with the exception of green barrel-like objects, black pavement, and Glass surfaces. This ink can inhibit the movement of Inklings that do not have a matching color. When used as a projectile, ink can damage opposing Inklings. In squid form, an Inkling can swim and jump quickly through ink of the same color, using this mechanic to swim up walls and through wire fences and grates into areas that are not typically reachable. However, squids cannot travel past striped barriers, preventing them from swimming into inaccessible areas. While squids form inklings are in their own ink color they will be invisible if they stay still and when moving only slight ripples will appear. While in ink, they will also gain more ammo or paint the humanoid inkling can fire. When squid form inklings are on land without paint, they will be very visible and move very slowly, even slower then a humanoid inkling.

Inklings are unable to swim in water. When underwater, their form dissolves for unknown reasons. The official American Splatoon Tumblr has mused that this may be because their bodies are actually made of liquid. Another reason to support this is that squid form inklings can go through grates, but since squids don't have bones then it might just be that they can easily fit through the holes.

Communication and language
Inklings communicate with each other in the Inkling language. They can be found talking to each other in Inkopolis Plaza. Written Inkling appears frequently in-game: on signs, in Sunken Scrolls, etc. The Squid Sisters talk and sing in Inkling. Inklings speak to teammates in Inkling when Signals are used in online battles.

So far, there have been no successful attempts at decoding the language, leading some to believe it is gibberish.

Splatting
While in battle, Inklings can use their weapons to splat others with ink. Standing in enemy ink will damage and slow an Inkling, but only enemy fire is able to splat an Inkling. When splatted by an enemy, Inklings explode into enemy ink, their gear and weapons drop, and a ghost-like squid figure will rise into the air where they were splatted. Inklings can also be splatted from trying to swim in water and dissolving or falling off a ledge and exploding into their own ink. Inklings respawn at Checkpoints after being splatted in both Octo Valley and online battle modes. It is unknown whether or not being splatted is another term for dying and Inklings respawn after death or if Inklings can actually die, but through other means.

Profiles and bios
"Transform into a squid to hide, climb walls, or travel at super speed in your own ink. But watch out for enemy ink—it'll hurt you!"

- Splatoon's official website

"The squid-like residents of Inkopolis are totes crazy for color-flinging, ink-slinging, turf-splattering battles."

- Splatoon's official website

"From squid…to kid…and back! Inklings can transform at will into squid form, so you've gotta master both if you want to win."

- Splatoon's official website

"Swim up ink-splattered walls and jump from one splat to another in squid form."

- Splatoon's official website

"Find shortcuts and navigate tricky areas."

- Splatoon's official website

"Avoid being targeted by baddies by hiding in your own ink."

- Splatoon's official website

"Turn into a squid to move more quickly across your ink."

- Splatoon's official website

"Hide as a squid, then quickly switch to an Inkling to take enemies out of the action with a well-aimed splat."

- Splatoon's official website

Trivia

 * According to the EDGE article, Inklings get full control of their squid and human forms at age 14. Since the playable Inklings seem to have full control of their squid and human forms, one can assume that they are at least 14 years old.
 * An Inkling's ink color is random online unless the Ink Color Lock option has been turned on, while in Octo Valley, it depends on the chapter.
 * The developers said when they came up with the concept, they didn't consider Bloopers from the Mario series, despite the close resemblance between Bloopers and Inklings.
 * A trophy of a female Inkling appears in Super Smash Bros. for Nintendo 3DS and Wii U, which becomes available after downloading the Inkling Mii Fighter costumes.
 * The trophy is actually shaped like the Inkling Girl amiibo.
 * When designing the Inklings, the Splatoon development team centered around the girl at first, to the extent that they thought at first to not have a boy Inkling. They emphasized on the girl Inkling because there weren't many female leads in Nintendo games, and that having a strong, active female lead would make it easier to become accepted overseas. The boy Inkling was created later.