Hero Roller

The Hero Roller is a roller in Splatoon and Splatoon 2 that is exclusively used in single player modes.

Splatoon
The Hero Roller is a futuristic weapon with a black and lime green color scheme and many blue lights that leave a small trail as Agent 3 moves. It is used exclusively in the Inkling Boy amiibo challenges. It behaves similarly to the Splat Roller, being able to fling a decent amount of ink and spread ink by rolling it on the ground. It cannot be upgraded with Power Eggs like the Hero Shot. Unlike the Hero Shot it only comes with Splat Bombs. It is exclusively used by the player during the Inkling Boy amiibo challenges. Beating all amiibo missions unlocks the Hero Brella Replica for purchase at Ammo Knights.

Splatoon 2
The Hero Roller now has a design closer to the Carbon Roller and is now usable in Octo Canyon and can now be upgraded one level. Unlike the first game, they now come with switchable sub weapons of Splat Bombs, Curling Bombs and Autobombs, along with every other hero weapon. It is loaned by Sheldon during the level, Enter the Octohurler, and can be used in missions after beating the level. Beating all missions in Octo Canyon unlocks the Hero Roller Replica for purchase at Ammo Knights.
 * Lv.1: Has Blue Lights
 * Lv.2: Has Red Lights, requires 1500 Power Eggs and 3 Sardinium. Increases power when flinging and rolling. Also increases speed at which you fling.

Hero Roller Replica
The Hero Roller Replica is a reward in Splatoon and Splatoon 2 unlocked through various means. It is a roller-type main weapon and is visually identical to the Hero Roller. Despite its unique appearance, it is simply a reskin of the Splat Roller from that game, sharing the same stats and loadout, sub weapon and special weapon.

Trivia

 * Callie's main weapon is shown to be the Hero Roller or its Replica, likely from her time in the role of Agent 1. This is shown in her artwork for the Go all out! vs. Focus on healing Splatfest.