Hero Charger

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

Splatoon
The Hero Charger 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 behaves similarly to the Splat Charger, with great range, accuracy and damage. It cannot be upgraded with Power Eggs like the Hero Shot can be. Agent 3 can only use Splat Bombs with this weapon, unlike with the Hero Shot. It is exclusively used by the player during the Inkling Girl amiibo challenges.Beating all amiibo missions unlocks the Hero Charger Replica for purchase at Ammo Knights.

Splatoon 2
The Hero Charger now has a more sleeker design, 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, Octozeppelin Invasion, and can be used in missions after beating the level. Beating all missions in Octo Canyon with the Hero Charger unlocks the Hero Charger Replica for purchase at Ammo Knights.
 * Lv.1: Has Blue Lights
 * Lv.2: Has Red Lights, requires 1500 Power Eggs and 3 Sardinium. Reduces charge time and allows you to execute a full-charge attack even faster.

Hero Charger Replica
The Hero Charger Replica is a reward in Splatoon and Splatoon 2 unlocked through various means. It is a Charger-type Main Weapon and is visually identical to the Hero Charger. Despite its unique appearance, it is simply a reskin of the Splat Charger from that game, sharing the same stats and loadout, Sub and Special.

Trivia

 * The Hero Charger looks slightly similar to the real-life M16 rifle, an iconic weapon and the standard for many armies around the world. However, the M16 is an assault rifle, not a sniper rifle.
 * Marie's main weapon is shown to be the Hero Charger or its Replica, likely from her time in the role of Agent 2. This is shown in her artwork for the Go all out! vs. Focus on healing Splatfest. In the final battle of Splatoon 2's Octo Canyon mode, she uses the Splatoon version of the Hero Charger to take out Callie's hypnoshades.