Herobrush

The Herobrush is a brush in Splatoon 2 that is exclusively used in Octo Canyon.

Description
The Herobrush has a very similar design to the Octobrush and is usable in Octo Canyon and can be upgraded one level. Like all hero weapons of Splatoon 2, they come with switchable sub weapons of Splat Bombs, Curling Bombs and Autobombs. It is loaned by Sheldon during the level, Underground Expressway, and can be used in missions after beating the level. Beating all missions in Octo Canyon unlocks the Herobrush Replica for purchase at Ammo Knights.
 * Lv.1: Has Blue Lights
 * Lv.2: Has Red Lights, requires 1500 Power Eggs and 3 Sardinium. Increases fling speed and power. Also increases run speed while inking.

Herobrush Replica
The Herobrush Replica is a reward in Splatoon 2 unlocked for purchase at Ammo Knights by beating all missions with the Herobrush. It is a brush-type main weapon and is visually identical to the Herobrush. Despite its unique appearance, it is simply a reskin of the Octobrush, sharing the same stats and loadout, Autobombs and the Inkjet.

Trivia

 * Unlike every other Hero weapon where the design and replica is based of the main weapon in it's class or sub-class, the Herobrush is based off the Octobrush and not the main weapon of the brushes, the Inkbrush. This is presumably to provide a Hero centric counterpart to the Octarian based Octobrush.