Octostomp

For the mission in Splatoon 2, see The Octostomp Returns.

"I'm BAAAAAAAAACK!"

- The Octostomp at the beginning of The Octostomp Returns mission.

The Mighty Octostomp is a one of the Great Octoweapons encountered in Octo Valley and later reappears in Octo Canyon and Octo Expansion.

Background
The Octostomp was an Octoweapon created during The Great Turf War by the Octarians. When it seemed that victory had smiled upon the Octarian army, a plug was pulled and caused the Octostomp and the rest of the Octarian mechs to shut down. Nearly 100 years later the Octostomp was brought back to life by the power of a Zapfish in order to attack once again.

Description
The Mighty Octostomp is a robotic Octarian in the shape of a large cube with several layers on its Octotrooper-like face covered in purple ink. It has 9 metal panels on most of the sides other than the front and bottom, and has a hole on its back where a tentacle can grab Zapfish. It also has two Octarian feet that somehow are strong enough to make the Octostomp jump. In the second game the Octostomp is given a ink-proof jacket that appears to be made of thermal fabric along with a rubber belt.

Octo Valley
In Splatoon, the Octostomp is the first boss Agent 3 encounters. It appears in the mission, The Mighty Octostomp!, where they have to dodge its attacks and climb up its body to splat the tentacle. Each time it will remove several panels from its body making it harder to climb. Once Agent 3 has splattered the tentacle a third time, Octostomp will be defeated and explodes.

Octo Canyon
In Splatoon 2 The Octostomp is back in the fittingly named mission, The Octostomp Returns, where this time it comes with a few tricks up its sleeve. The first phase plays out normally where Agent 4 must dodge then climb its back to splat the tentacle. In the next phase however, it then gains an uninkable coat with a belt around it and is called the "Neo Octostomp". Now Agent 4 must splat the buckle to remove the coat while avoiding a Splatling and continue from there. In phase 3, it'll once again obtain the coat but now has two extra faces making things more difficult for the hero. After the third tentacle has been splatterized it then, just like last time, inksplodes.

Octo Expansion
The Octostomp returns a third time in the Octo Expansion, where it has been Sanitized and renamed "Octostomp Redux". It now resides in Drop the Bass Station where it can be battled. The boss battle goes very similar to the one in Octo Canyon with its ink-proof coat but now is able to use the Bubble Blower special. After Agent 8 has splattered the tentacle enough times, Octostomp Redux will be defeated and (like always) explode.

Trivia

 * So far, the Octostomp is the only boss to be battled in all of the single player campaigns.
 * The Octostomp is the only Octoboss to have any dialogue.
 * Octostamps, Octostamp DXs, and Octoseekers all appear to be based on the Octostomp.
 * It is so far unknown how Kamabo Corporation managed to copy and sanitize the Octostomp along with the rest of the Octobosses.
 * It is also implied that the Octostomp remembers its last battle when it says “Back like I never left”, despite being Sanitized.