Squid Hairclip
From Inkipedia, the Splatoon wiki
Template:Infobox clothing The Squid Hairclip is a Headgear item that can only be obtained through the Inkling Girl Amiibo. It's ability is Swim Speed Up (Increases swimming speed while submerged in squid form.)
Complete these 4 missions the Amiibo gives you to unlock it:
01 Octotrooper Hideout ~ Catch That Zapfish! ~
02 Lair of the Octoballs ~ Splat Your Way to the Top! ~
03 Rise of the Octocopters ~ Leap to Victory! ~
1 Squish, Squash, Smash... The Mighty Octostomp!