Kraken
From Inkipedia, the Splatoon wiki
The Kraken is a Special Weapon in Splatoon. The Inkling Squid amiibo provides single player challenges that involve using the kraken throughout the entire level.
Description
For a short period of time, player will change into an invincible Inkling in a monster-like Squid form . It can move freely on enemy's ink while making ink and destroying enemies when touched.
Usage
Like all special weapons, the Kraken must be charged by before use, accomplished by spreading ink. Once charged, the player may click the right analog stick, activating it. When activated, a message with the player's image and the special used (in this case, the Kraken) is displayed for teammates to see.