Splatoon 4 Boss Guide: How to Beat Every Octarian Boss & What the Next Campaign Could Throw at You

Splatoon bosses are not like other game bosses. Honestly, they're weirder. No health bars. You shoot tentacles until the main weak point opens, then unload as much ink as possible before it closes again. Then you do it again. And again. Rinse and repeat two or three times while dodging increasingly chaotic attack patterns. It sounds simple when I write it out like that. But the execution is where things get spicy.

The boss that's been with the series the longest is DJ Octavio. He's the Octarian king, fought at the end of Splatoon 1's campaign inside his giant mech, returned in Splatoon 2 with an upgraded flying version, and showed up again in Splatoon 3's story in a slightly different role. Octavio is basically the Bowser of this series, he shows up, you fight him, sometimes he helps you against a bigger threat, then he's back being the antagonist. The pattern for his fights is always the same: he attacks in cycles, each one faster than the last, and between cycles you get a window to fire back.

In Splatoon 1, the Octavio fight was pure spectacle. His mech had giant fists that punched the stage, shockwaves you had to jump over, missiles that tracked your position, the whole deal. Between attacks he'd open his mouth, yes, the mech had a mouth, and you'd fire ink inside. The second phase added faster attacks and smaller vulnerability windows. Classic pattern. Honestly I kind of miss how straightforward it was compared to what came later.

The Splatoon 2 version added flight and homing punches that covered more of the arena. You had to use the Rainmaker, the special weapon that's usually a multiplayer mode objective, to knock him down before dealing damage. This fight was harder than the first one. Partly because the Rainmaker is slow to charge and you're vulnerable while carrying it. And partly because the homing punches tracked way more aggressively. Not my favorite boss fight tbh.

Splatoon 3 broke the formula entirely. The final boss wasn't Octavio, it was Mr. Grizz. And instead of a mech fight, you were on a rocket launching into space, dodging fuzzy ooze while the arena literally shifted around you. The smallfry companion you'd had the whole campaign turned out to be the key to winning. That's the kind of narrative payoff you don't expect from a game about squid kids shooting ink.

If you're preparing for Splatoon 4's campaign, here's what I've learned from beating every series boss.

First, watch the tentacles. Every Octarian boss telegraphs its attacks through the movement of its mechanical tentacles before the actual hitbox appears. Once you learn which tentacle movement means which attack, the fights become pattern recognition rather than reaction tests. The Octo Shower in Splatoon 2, for example, would tilt its central nozzle before spraying ink in that direction. You had about a second to move. That's generous by Splatoon standards.

Second, keep the ground inked. I know this sounds like Turf War advice bleeding into boss fights, but it's genuinely critical. Most boss arenas are huge and the attacks cover a lot of space. If you can't swim away when a shockwave or ink spray comes at you, you're dead. Ink the arena during downtime. Every time. There is no boss fight in this series where you regret having more ink to swim through.

Third, burst damage matters more than sustained damage during the weak point window. When the boss opens up, you have maybe three to four seconds. That's it. A Splatling with a full charge, a Charger shot timed perfectly, a roller flick, these do more in that window than spraying with a Shooter. I learned this the painful way against the Octo Samurai in Splatoon 2. Took me four attempts because I kept using the wrong weapon for the damage phase.

Fourth, some bosses have multiple targets. The Octomaw in the first game had individual teeth you had to shoot before the tongue became vulnerable. Prioritizing the right target is the difference between a clean kill and getting splatted by a flailing metal mouth.

Let me talk about Salmon Run bosses too. They're the other major source of boss encounters in Splatoon and honestly, they're the ones that kill you the most. In Salmon Run's horde mode, boss Salmonids appear during each wave and each one requires a specific tactic. The Steelhead throws bombs and its only weak point is the balloon on its head, which inflates before it attacks. The Flyfish launches missiles and you have to throw bombs into its open hatches, two bombs, one for each side. The Stinger stacks pots and fires a beam through walls that tracks your position. There's like eight or nine of these things and each one is its own mini puzzle. Maws, Scrappers, Drizzlers, you get the idea.

Steel Eels are the ones that wreck new players. They're a long segmented body piloted by a small Salmonid at the front, trailing ink behind them. You have to circle around to hit the pilot. But the body blocks your shots and if it circles you, you're trapped. The trick is to have one teammate bait the Steel Eel while another shoots the pilot from the side. Basic team coordination. And random freelance groups fail at it constantly. So frustrating.

The King Salmonid fight at the end of an Xtrawave is the ultimate boss test. Cohozuna, Horrorboros, Megalodontia. These things have enormous health pools and the timer is just rude. You need to use egg cannon shots from boss drops, and the golden egg you get from a defeated boss Salmonid becomes your primary damage source. I've won maybe half my Xtrawaves. Maybe less. Every loss felt like we were ten seconds short. It's brutal in the best way.

What will Splatoon 4's bosses look like? The series has been moving toward more cinematic, narrative-driven encounters with each entry. Splatoon 3's final boss on a rocket was a massive step up from the arena fights of previous games. And with Switch 2's hardware, there's room for more dynamic environments, bigger set pieces, and boss mechanics that wouldn't have been possible on the original Switch. The Splatoon Raiders spinoff is introducing an open-world structure, and if that DNA carries into Splatoon 4's campaign, we might get boss encounters that aren't locked to single arenas. Roaming bosses. Environmental destruction. Chase sequences. Honestly who knows what Nintendo's cooking at this point.

If you're struggling with a specific boss right now in Splatoon 3 preparing for 4, the best general advice I can give is slow down. Boss attacks in this series are designed to make you panic and run into the next attack. Stay calm. Watch the pattern. Ink when you can. Shoot when it opens. Every boss in this series falls apart once you stop panicking.