What is the name of the final boss in Splatoon?

The final boss in Splatoon is DJ Octavio.

DJ Octavio is the leader of the Octarians and the principal villain of the original Splatoon’s single-player campaign. In the story, the Great Zapfish disappears from Inkopolis, and Agent 3 enters Octo Valley to investigate. The trail leads to Octarian forces and ultimately to Octavio, who is seeking revenge against the Inklings.

The final confrontation takes place after Agent 3 reaches Octavio’s hideout. He battles from inside a giant mechanical war machine, using oversized fists, missiles, ink attacks, and other hazards. The fight combines platforming with Splatoon’s core movement and shooting mechanics.

Several other names in the options belong to different parts of the wider franchise. Commander Tartar is connected to Splatoon 2’s Octo Expansion, Mr. Grizz runs Grizzco and is central to Splatoon 3, and “Octo” is a general term rather than the original game’s final boss. DJ Octavio also returns in later Splatoon stories.