Octoleet Armor
From Inkipedia, the Splatoon wiki
The Octoling Armor is clothing in Splatoon. It is 2-star rarity produced by the Cuttlegear clothing brand and comes with the main ability, Ink Saver (Sub).
It cannot be purchased: it must be won by playing Hero Mode with the Squid Girl amiibo.
Appearance
Abilities
The Octoling Armor comes with the Ink Saver (Sub) ability as a main ability.
Unlock
Complete these 4 missions the Amiibo gives you to unlock it: