It seems as that the Splatoon updates never stop. According to Splatoon's official Tumblr blog, the Slosher Deco will be available tonight, 6 PM PT as a free update.

Sloshers are a bucket type weapon that throw a large amount of ink at once in a mid-ranged arc. The "Deco" variation of the Slosher is a reskinned variation of the weapon with a different Sub Weapon (Splash Wall) and Special Weapon (Kraken).