Octarians

The Octarians are the antagonistic species of the story mode in Splatoon. They reside in Octo Valley, and are responsible for stealing the Zapfish from Inkopolis. Their ink colour is dark magenta.

Appearence
Octarians usually resemble tentacles rather than full octopi. They are red and cream colored, with their suckers present on the red side of their bodies, googly yellow eyes, purple lips, and tiny hilarious legs in black boots. They come in a variety of forms, and the line is often blurry when it comes to what is an Octarian and what is mechanical, suggesting they may use some manner of biotechnology.

History
The sunken scrolls suggest the Inklings and Octarians were not always enemies, but rising sea levels forced them to compete for remaining territory, eventually culminating in the great Turf War. The Octarians initially won through use of their Great Octoweapons, and the fact that they were able to get up earlier than the Inklings. However, the Inklings rebounded when a plug was "carelessly pulled from its socket" and the weapons were deactivated. The Inklings believe they were able to win due to their superior number of limbs.

Sometime afterwards, the Octartians built themselves underground dwellings in the form of a series of spheres connected by kettles. This area became known as Octo Valley. However, as their domes began to deteriorate and electrical power became scarce, the Octarians turned their sights to the Inklings aboveground, and their Zapfish as a source of power. The player character's mission in the game's Hero Mode is to quell the uprising and return the stolen Zapfish to the surface.

Types of Octarians
All Octarians encountered in Hero Mode serve in the Octopus army, where they are classified by body type, combat role, and skill: In addition to the Octarians themselves, the octopus army is also supplemented by robots:
 * Octobomber
 * Octoling
 * Octotrooper
 * Twintacle Octotrooper
 * Shielded Octotrooper
 * Shielded Twintacle Octotrooper
 * Snorkel Octotrooper
 * Snorkel Twintacle Octotrooper
 * Octosniper
 * Octoballs
 * Octocopter
 * Octostamp
 * Octostriker
 * Suckerfish
 * Flooder
 * Explode-o-bots

The Great Octoweapons
A set of five immensely powerful war machines developed by the Octopus Army at the height of the Great Turf War, and were thought to be destroyed by the Squidbeak Splatoon. Rebuilt secretly by the Octopus Army, they serve as the bosses of each zone in Octo Valley.
 * The Mighty Octostomp
 * The Dreaded Octonozzle
 * The Rampaging Octowhirl
 * The Ravenous Octomaw
 * DJ Octavio's Octobot