Splatoon 3 Rise of the Mammalians lore and ending, explained

Splatoon 3’s story mode is a fun ride, full of twists and turns. While the story can be understood, there are logs that the player can find throughout Alterna that will help enhance the story even more, even fleshing out the campaign’s antagonist. However, if you don’t want to find all the logs in order to decipher what lead up to the events of Splatoon and the mastermind’s plan or just want a rundown of the game’s plot and ending, here is the full story of Splatoon 3 Rise of the Mammalians.

Splatoon 3 Rise of the Mammalians explained

The game opens up with news of the Great Zapfish disappearing. Without the Great Zapfish, Inkopolis and Splatsville will be without power. Craig Cuttlefish tells you that the Octarians stole it and he needs your help in getting it back. Dubbing you the new Agent 3, you join him on the quest to get Great Zapfish back. As you make your way through the first area, you have to avoid the strange Fuzzy Ooze that’s covering every inch of land. If touched, it’ll turn that person into a fuzzball. The origins of the Fuzzy Ooze are cast aside for now until you reach the bottom of the area and fight DJ Octavio. After beating him though, it’s revealed that the Octarians have nothing to do with this. In fact, Octavio reveals that the Ocatrians are also victims of whatever is going on, saying someone is corrupting the world with the Fuzzy Ooze.

Agent 3 gets split up from Cuttlefish and finds themself in a land called Alterna, a snowy area that is just covered in Fuzzy Ooze. Here Agent 3 meets Callie, Marie, and the main character from the first game who are also trying to figure out what’s going on. Cuttlefish is nowhere to be found. In fact, when he tries to contact Agent 3 and the others to tell them what’s happened, his communication gets cut. So, it’s the main character’s job to try and find Cuttlefish and the Great Zapfish while also figuring out what and where that Fuzzy Ooze came from.

After navigating through the island and fighting Deep Cut, who just wants treasure and isn’t actually connected to the mastermind, it is eventually revealed that Cuttlefish has been kidnapped by none other than Mr. Grizz. This figure has been shrouded in mystery ever since he popped up in Splatoon 2 as your boss in Salmon Run, but his intentions for running that business as well as what he looks like is finally revealed in Splatoon 3.

Through a series of logs that the player can find if they explore Alterna, it’s revealed that a rocket containing some of the last remaining humans and three bears tried to leave Earth but ran out of fuel, causing them to drift in space for thousands of years. While those humans perished, Mr. Grizz, managed to survive through hibernation and woke up back on Earth after the rocket crash-landed. He then saw that the Earth has been populated with Inklings, Octolings, and other sea life.

Eventually, Mr. Grizz found Alterna, where he discovered a rocket and the mysterious Fuzzy Ooze that if touched, will turn any living being into a mammal. Finding out it was possible to bring back mammal life, Mr. Grizz made it his mission to bring mammals back and “restore balance to the Earth.” However, in order to bring his plan to fruition, he needed to make more of the Fuzzy Ooze and power up the rocket that he would use to go into Earth’s atmosphere and cover it in said Ooze. He realized then that Salmon Eggs could produce more of the Fuzzy Ooze while Power Eggs could power up the rocket. That’s why he made Grizzco. He needed to hire sealife to collect these eggs for him. All this time, players have unknowingly been aiding Mr. Grizz in his evil plan.

When Agent 3 reaches Mr. Grizz, Cuttlefish has been reduced to a squid and Mr. Grizz launches off on the rocket, getting ready to cover the Earth in Fuzzy Ooze and in turn make everyone turn into mammals. With the help of Deep Cut and the others, they launch Agent 3 into space. Agent 3 gets to the rocket and confronts Mr. Grizz, initiating the final boss fight in the game.

Splatoon 3’s ending explained

After defeating Mr. Grizz and sending him deep into space, everyone returns to Earth with the Great Zapfish in tow. Deep Cut reports on the news of the Great Zapfish’s return. Also making a return is the Squid Sisters, who have released a brand new single called “Wave Goodbye.” Deep Cut hopes to go on tour with them and make a spectacle that no one can forget. The player is then shown the credits with “Wave Goodbye” playing in the background.

Something to note here is that while Mr. Grizz appeared to have died from your battle with him, during the credits, you can see him floating around in space with his ears open, implying that he’s alive and well. With Mr. Grizz being alive, it’s entirely possible that he could re-appear in future DLC or another Splatoon game down the line, though he’ll have to find a way to get back to Earth first.