Grapplink
From Inkipedia, the Splatoon wiki
'Grapplinks are a Mechanic in Splatoon 2s Octo Canyon. They are black spheres with flashing yellow lights, a propeller and hooks, that float in the air. When hit with ink from a main weapon or with a sub weapon, the player is quickly pulled towards them and will reach a point just under them before starting to fall down again.