Propeller-Lift Fortress
From Inkipedia, the Splatoon wiki
Propeller-Lift Fortress is the sixteenth mission available in singleplayer Octo Valley. It is the first mission of the fourth area after the third boss, The Rampaging Octowhirl!. The mission is named as such because of its heavy use of Propellers. It is also the first level to introduce Kelp Octolings.