The Rampaging Octowhirl!

The Rampaging Octowhirl! is the third boss mission in Splatoon's single-player mode, Octo Valley.

Octo Valley
To unlock The Rampaging Octowhirl, the player must complete all six missions of Area 3. The Boss Kettle is located in the center tower, but the player must ink up the walls on the side, swim up to the grate platforms, and climb carefully to the top to reach it. Be warned that there are walls to climb up from grates, and turning to a squid too early could lead the player to drop back down to the ground.

Boss Appearance
The Rampaging Octowhirl appears to be a giant metal spinning-top clam with spikes, purple eyes and a protruding red tentacle. Its lower half glows in a spotted pattern when enraged. The eyes are shielded by a transparent shell, and blink similarly to a malfunctioning lightbulb. Purple ink pours from the centre of the Octowhirl as it spins. The underside of the Octowhirl is adorned with a large spike which it balances upon, and can be retracted within the shell.

Walkthrough
The Octowhirl spins around to the edge of the arena, followed by tilting onto its side and rolling directly towards the player at high speed. The player must cover the path in ink so that the Octowhirl sinks, exposing the tentacle inside it. When sufficiently coated the Octowhirl should suddenly drop downwards and the tentacle pop up in the centre, but if the player misses they can be steamrolled as the boss restarts their attack cycle.

On the second instance, the Octowhirl activates the arena floor, making the three sections rotate in opposing directions. The floor can either be inked entirely or the player can lure the boss into their path after shooting ink further to the side to match the rotation of the tiles.

In the final part, the Octowhirl removes a large amount of the floor tiles, significantly reducing the available space for ink. The player should follow the path of the central platform and walk backwards, inking up to the edge as the Octowhirl will likely only sink when inches away from the player. After destroying the tentacle for the third time, the Rampaging Octowhirl explodes, revealing a blueprint and the Zapfish.

Trivia

 * The Rampaging Octowhirl is based on a mixture of a giant clam and a spinning top or dreidel.
 * Submerging the Octowhirl in ink is done in a similar way to Octoballs, the only difference being the amount of ink needed.