Cuttlefish

"This unreasonably attractive gentleman goes by the name of Cap'n Cuttlefish. He’s a decorated hero who fought in the Great Turf Wars of legend between the Inklings and Octarians. He now keeps solemn vigil over Octo Valley, watching for any fishy behavior. Though his clothes may be tattered, his heart is pure and nothing escapes his razor-sharp gaze. He also TOTALLY didn’t write this post."

- Live from the Squid Research Lab

Craig Cuttlefish, more commonly known as Cap'n Cuttlefish (Japanese: アタリメ司令 Atarime Shirei) is a main character in Splatoon, and the only known Inkling older than 21 years old. He acts as a guide for the protagonist, issuing them the Hero Suit and title of Agent 3 in Octo Valley. He is also the grandfather of Callie and Marie.

History
Prior to the ultimate end of the Great Turf War, Cap'n Cuttlefish served as leader of a division called the Squidbeak Splatoon alongside Ammoses Shellendorf, Judd, and two unidentified Inkling soldiers. It is unknown what he did between the end of the war and the beginning of Splatoon, but he seems to have changed little.

Splatoon
Cap'n Cuttlefish can be found poking his head out of a manhole in the corner of Inkopolis Plaza. On the first time the player arrives at Cuttlefish's shack in Octo Valley, he introduces himself and recruits the player as Agent 3 to help take back the Great Zapfish from the Octarians. He provides assistance throughout the levels, until the completion of The Rampaging Octowhirl!, where he gets kidnapped by DJ Octavio. Agents 1 and 2 take over his role, until the final mission, where Agent 3 battles DJ Octavio to rescue Cap'n Cuttlefish, who is tied up in a chair. During the 4th phase, the Squid Sisters override the boss music, allowing Cuttlefish to set himself free.

Replaying the final mission results in new dialogue, describing how DJ Octavio escaped from his globe and recaptured Cap'n Cuttlefish.

Splatoon 2
In Splatoon 2, Marie takes over the role of Agent 4's guide / mentor. Sunken Scroll number 25 reveals Cap'n Cuttlefish went off travelling with Agent 3 for some kind of research trip "at the cape".

Octo Expansion
Cap’n Cuttlefish shows up in Octo Expansion as a guide throughout the levels. At the start, he guides Agent 8 to Central Station on the Deepsea Metro. He remains on the train for most of the game, and talks to Agent 8 in levels, previous chatlogs, and directly if talked to.

When Agent 8 collects the 'four thangs,' Cap’n Cuttlefish joins them when they walk into the telephone, which reforms into a blender using the thangs. Agent 3 saves them by destroying it, falling through the roof, and knocking themself out. For the rest of the levels, Cap’n stays to care for Agent 3 until the telephone awakens again, capturing him and mind controlling Agent 3.

After defeating the mind-controlled Agent 3, Cap’n Cuttlefish will walk with Agent 8 to go to the surface, where the telephone will emerge with a gigantic weapon for the final battle. Cap’n stays behind as the “hype man,” remaining on the helicopter until the boss is defeated, where he will join Pearl, Marina, Agent 8, and Agent 3 to go back to Inkopolis.

Later, he is found back on the Deepsea Metro train, as he wanted to check on everyone there. He lets Agent 8 know that he'll accompany them if there's anything they need from the Deepsea Metro.

Personality and traits
Cap'n Cuttlefish is a decorated hero who fought in the Great Turf Wars of legend between the Inklings and Octarians. He now keeps solemn vigil over Octo Valley, watching for any fishy behavior. Though his clothes may be tattered, his heart is pure and nothing escapes his razor-sharp gaze.

Cap'n Cuttlefish's favorite food is crab cakes❌/biscuits, as pointed out both by himself and Agents 1 and 2. He is often distracted by them, giving DJ Octavio the chance to escape from his snow globe prison.

Following his first meeting with Pearl, he has taken up rapping as a hobby.

Trivia

 * In the main hub of Octo Valley, the player can ink Cap'n Cuttlefish; he will eventually shake off the ink. However, it takes a considerable amount of ink to completely cover him, though, suggesting that he may be more resilient than the average Inkling, despite his age and frail appearance.
 * His cane is one of many Bamboozlers used by Inkling soldiers in the Great Turf War. However, he has never been seen to use it for its original purpose in-game, only as a cane. Interestingly, he is shown to be using it in a credits art.
 * On the corner of his shack, Cap'n Cuttlefish has taped up two small photographs of his grandchildren, one of Callie and one of Marie.
 * His shack appears to be filled books and zapfish dolls, along with pictures of octarians in the front.
 * During the initial tour of Inkopolis upon starting the game for the first time, he is referred to as a "creepy old dude".
 * The Legendary Cap is modeled after Cap'n Cuttlefish's signature hat.
 * The Old Timey outfit, including the hat, clothes, and shoes, is modeled after Cap’n Cuttlefish’s outfit in Octo Expansion.
 * In the Octo Expansion trailer, he is seen saying "I'll take your stunned silence as a YES!" to Agent 8. This mirrors 's "I'll take your awkward silence as a yes." to Agent 4, which in turn mirrored Cuttlefish's own "I'm gonna take your silence as a yes." to Agent 3.
 * According to the first artbook, Inklings are able preserve their bodies by sun-drying, which explains Cap'n Cuttlefish's long lifespan. In Octo Expansion, it’s confirmed that inklings lose ink and become more dry with age.
 * In Octo Expansion, the wallpaper on his phone is a picture of young Callie and Marie; the same photo from the Sunken Sea Scroll found in Splatoon.