Hero Shot

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

Splatoon
The Hero Shot is a futuristic weapon with a black and lime green color scheme and many glowing lights that leave a small trail as Agent 3 moves. It is used exclusively in the Octo Valley single player and the Inkling Squid amiibo challenges It behaves similarly to the Splattershot, with decent range, accuracy, fire rate, and damage. It's the only weapon in the game with multiple switchable sub weapons, (Splat Bombs, Burst Bombs and Seekers), however only the Splat bombs are usable during the Inking Squid amiibo challenges. Its fire rate can be upgraded with Power Eggs found in Octo Valley missions. Beating all amiibo missions unlocks the Hero Shot Replica for purchase at Ammo Knights.

These upgrades have no effect during the amiibo challenges.
 * No upgrades: Blue lights
 * One upgrade: Purple lights
 * Two upgrades: Yellow lights
 * Three upgrades: Green lights

Splatoon 2
The Hero Shot in Splatoon 2 is majorly redesigned and it is based of of the real life FN P90, the design that bears little resemblance to the original or the Splattershot. It now comes with switchable sub weapons of Splat Bombs, Curling Bombs and Autobombs, however every other Hero weapon also has these. It is now only upgradable twice, while the other Hero weapons can be upgraded once. Completing all missions in Octo Canyon with this weapon unlocks the Hero Shot Replica for purchase from Ammo Knights.
 * Lv.1: Primarily yellow
 * Lv.2: Now primarily orange, with an extra handle and an attachment near the nozzle, requires 800 Power Eggs and 2 Sardinium. Increases fire rate. Watch your ink consumption!
 * Lv.3 Now once again primarily yellow, with an extra attachment at the back of the gun, requires 1500 Power Eggs and 3 Sardinium. Increases fire rate. Watch your ink consumption!

Hero Shot Replica
The Hero Shot Replica is a reward in Splatoon and Splatoon 2 unlocked through various means. It is a shooter-type main weapon and is visually identical to the Hero Shot. Despite its unique appearance, it is simply a reskin of the Splattershot from that game, sharing the same stats and loadout, sub weapon and special weapon, and upgrades purchases through the Ammo Knights Enhancifier will not affect it.

Trivia

 * The Level 3 Hero Shot (and its replica) in Splatoon 2 resembles a real life FN P90.
 * The Hero Shot in Splatoon 2 is the only hero weapon to not have a red accent when fully upgraded.
 * In Octo Expansion, Agent 3 uses a Hero Shot, presumably the same one used in Octo Valley, with the original design from the first game, instead of the new design. However it is implied that they've modified it since as it functions very differently than before. However, it has blue lights, signifying it is not upgraded.
 * Agent 3 can dash at any time, as if they had Dualies, but the speed is slow like how the Drop Roller ability behaves.
 * During Agent 8's fight, Agent 3 has removed the limiter for Special weapons, meaning Agent 3 can presumably use Specials without having to charge it by turfing. It is also shown that Agent 3 can use multiple different Special weapons without the need for Canned Specials (which is possibly a result of the mind-hacking by the Telephone). They use Splashdown, Curling Bomb Launcher, Baller and Sting Ray during the initial fight. During Inner Agent 3, they use Splashdown, Inkjet, Bubble Blower, Autobomb Launcher and Tenta Missiles.
 * It is shown that Agent 3's Hero Shot still has a Sub weapon of Splat Bombs during Spinal Phase but during Inner Agent 3, Autobombs are now the Sub weapon. Considering Autobombs were not part of the original Hero Shot, it's likely Agent 3 modified the gun to be able to use them, like how they removed the Special limiter. This could also mean either the Hero Shot still has switchable sub weapons and can change between the Splat bombs and Autobombs or the sub-weapon was somehow changed between the two fights (although it's unclear whether the events of Inner Agent 3 actually happened or is simply a thought process, in which case it's possible Agent 3's Hero Shot never had Autobombs and the first 4 Specials used during that fight in the first place).