Return of the Mammalians

Return of the Mammalians​

Return of the Mammalians

Type	Single-player campaign
Players	1
Ranked
Weapons	Various
Controllers	Joy-Con Nintendo Switch Pro Controller
Release Date	Launch

This article is about the single-player mode of Splatoon 3. For the mission, see Return of the Mammalians (mission).

“	Join Agent 3 and the New Squidbeak Splatoon in a hairy fight against the unruly Octarians. Discover the secrets of Alterna and the Fuzzy Ooze.	”
— Splatoon's official website

Return of the Mammalians is a single-player game mode in Splatoon 3. It involves the player donning a Hero Suit and venturing into the Crater to defeat the Octarian army (which is now covered in hair), soon ending up in Alterna.

Story

An Inkling or Octoling accompanied by their "little buddy" Smallfry are scrap hunters who search for junk gems and splat it up in Turf Wars on the side. When they go through a manhole, they meet Craig Cuttlefish on the other end at the Crater, who dubs them the new Agent 3 of the New Squidbeak Splatoon. He explains that the New Squidbeak Splatoon's continued mission is to stand in opposition of the unruly Octarians, who are suspected to be behind the recent disappearance of the Great Zapfish from Splatsville.

The areas throughout the campaign have a large amount of Fuzzy Ooze. To get through areas, Agent 3 has to take care of the Fuzzy Ooze, which Smallfry can eat as long as they have the adequate amount of Power Eggs. Cuttlefish also notices that the Octarians have fur grown over their body, as opposed to their previous appearances where they were smoother. When Cuttlefish tries to contact Agent 1 and Agent 2 to come pick them up, DJ Octavio intervenes but Cuttlefish dismisses it as his radio being broken.

After reaching the center of the Crater, DJ Octavio appears in his battle mech named the Octobot King L3.Gs, trying to confront the two for the recent disappearance of his Octarian army, but when asked about the stolen Great Zapfish, states that he does not even know about it this time, and engages Agent 3 in a fight. Upon being defeated, Octavio tells Cuttlefish and Agent 3 that he indeed did not steal the Great Zapfish. Cuttlefish thinks that someone else might have done it, but before they can continue, the ground beneath them collapses as Fuzzy Ooze flows out. A tentacle-shaped piece of Ooze takes Cuttlefish away from Agent 3, who loses their Hero Suit and Power Eggs in the fall. Agent 3 then wakes up in Alterna, where they are greeted by the New Squidbeak Splatoon, comprised of the old Agent 3 (now Captain) and the Squid Sisters.

The new Agent 3 is also aided by a robotic assistant known as O.R.C.A., who helps guide them through Alterna.

At the end of Site 1, Future Utopia Island, Deep Cut makes their entrance and makes it clear that all the loot in Alterna belongs to them. Later, each of them guards one of the three 'treasures' in the area and Agent 3 has to defeat them to continue.

After collecting all three parts of the Treasure, Callie and Marie assemble it into a lawn mower-like tool, which the Captain uses to cut off the fur near the rocket at Alterna Space Center so the team can go there and save Cuttlefish.

The Captain gets hurt while using the tool, and it also breaks down. Soon after this, Deep Cut appears again, trying to take back the treasure, but Marie tells them that the New Squidbeak Splatoon does not need the treasure and that they can have it back. Deep Cut then asks Marie to be their boss, who reluctantly accepts.

On their way to the rocket, the party overhears that Mr. Grizz plans to use Cuttlefish and the Golden Eggs (collected by the unwitting Inklings and Octolings in Inkopolis and Splatsville working in his company) to 'restore the balance of the world'. When asked about the reason for hunting treasures, Shiver and Frye explain that they want to sell the treasure to help those in need in Splatsville, while leaving little to themselves, which makes Callie and Marie respect them.

After completing all the sites, Agent 3 has to get on the Ooze-covered rocket. Once they get to the top, they and the New Squidbeak Splatoon find Cuttlefish dried up and lifeless, as a result of being dehydrated by Mr. Grizz. Grizz, now revealed to be a grizzly bear, then appears and escapes on the rocket, aimed to spread Fuzzy Ooze all over the Earth and bring forth a new era of mammalian dominance.

The Captain drops a tear on Cuttlefish's body, which makes him come to his senses. Deep Cut appears again and helps Agent 3 and Smallfry reach Mr. Grizz's rocket. There, Agent 3 and Mr. Grizz engage in a fight. After having some of his Fuzzballs splatted, Mr. Grizz knocks Agent 3 and Smallfry out from his rocket as he absorbs the Fuzzy Ooze and plans to send it on the Earth himself. Now, DJ Octavio, now knowing who the true culprit is, appears in his modified Octobot to save the two. DJ Octavio, the Squid Sisters and Deep Cut then play the Calamari Inkantation 3MIX together, causing Smallfry to become Hugefry. They then fight Mr. Grizz as DJ Octavio and Agent 3 vacuum the Fuzzballs on Mr. Grizz's body, before blasting him back with the ooze, defeating him. After emerging victorious, DJ Octavio, Agent 3 and Smallfry return to the Earth together.

Gameplay

Mechanics

Comparing to the Hero Mode of the previous two games, Return of the Mammalians has a less linear progression similar to the Octo Expansion. Upon entering a mission, O.R.C.A. explains the rule of the level with dialogue and prompts the player to select one of the sets of weapons available. Different sets of weapons may have different Power Eggs rewards. Some missions also cost Power Eggs to play, and/or have special conditions that will cause the player to get splatted if they fail.

The areas in this mode are covered in Fuzzy Ooze, which serves as the obstacle blocking the path to other areas, rather than having the missions locked themselves. The player needs to use the Power Eggs they collect from the missions to clear them and progress.

The map screen in each of the sites tracks how many of each type of item the player has found on the overworld (loot anchors that contain decorations, golden records, Sardinium, and Sunken Scrolls). The map highlights areas with unobtained items to find in green, labeled as Areas of Interest, whereas it marks areas which the player hasn't been to yet with black striped squares labeled Parts Unknown. If the player fully collects all items in a site and goes to every possible part of the map so that there are no longer any black squares, the site becomes marked as "Surveyed". Marie will award the player with a piece of the map of Alterna as a sticker if they survey that site.

Fully surveying all sites causes a Shel-drone to appear. Each day the player can charge this drone by using 999 power eggs. The following day, the drone will send an item to the lobby terminal. These items include cash, ability chunks, and meal tickets, as well as decorations that can only be found in Alterna. This is currently the only way to get duplicates of these decorations. If the Shel-drone doesn't appear after the player surveys every area, they will need to go back to Splatsville, and then Alterna again.

Missions

Prologue: The Crater

No. 1 Octarians in the Crater? YIKES!

No. 2 Sink into the Ink and SWIM!

No. 3 Boxes Locked! Keys, Please!

No. 4 What Are They? Can We Stop Them?!

Crater  Octobot King L3.Gs

Site 1: Future Utopia Island

0101 Get to Know Alterna, Your Only Choice

0102 Octopods at Rest Tend to FLIP OUT!

0103 Splat You on the Flip Side

0104 Doors, Doors, Doors! And More! (Doors)

0105 Relic Restoration

0106 Zip, Splat, and Jump

0107 Become One with Your Smallfry

0108 What Caused the Big Bang? YOU!

0109 The String's the Thing

0110 Deadly Dance Hall—Jump, Jump!

0000 After Alterna

Site 2: Cozy & Safe Factory

0201 Twirling, Swirling, Whirling

0202 Absorbency and You

0203 Soak It to Me!

0204 Splitting Crosshairs

0205 Tread Heavily

0206 Getting Lost in Three Easy Steps

0207 The Ink-Conservation Project

0208 Switching Things Up

02  The Future Stares Back

Site 3: Cryogenic Hopetown

0301 Climbing the Corporate Splatter

0302 They Said We'd Have Flying Cars, and We Do! Kinda!

0303 Ink Wheels—Experience Tomorrow's Technology Today!

0304 Try Curling! Alterna's 11th Most Popular Athleisure Activity!

0305 Conveyor-Belt Tightening

0306 Time Trial and Errors

0307 Rail Pass

Site 4: Landfill Dreamland

0401 Propellered to Greatness

0402 Octohoppers Don't Have a Sense of Humor (and They Hate Puns)!

0403 Let's Put a Pin in That

0404 Splash the Block Party

0405 Amusing a Bemused Muse

0406 Those Aren't Birds

0407 Charge Now, Splat Later

0408 Easy Ride, Tricky Targets

0409 Flying Worst Class

0410 Ink Fast, Hotshot

0411 Stamp 'Em Out

0412 The Path to Perfect Penmanship

04  The Pursuit of the Precious

Site 5: Eco-Forest Treehills

0501 Trouble Round Every Corner

0502 The Upside to Enemy Backsides

0503 Uh-Oh! Too Many Snipers!

0504 Barriers! They've Got You Covered

0505 A Compulsive Collector's Paradise

0506 Zipping over the Neighborhood

0507 One-Way Ride through Target Town

0508 Making Waves with Splashdowns

0509 Low Viz, High Risk

0510 Shooter on Rails

0511 Simply Zipcastic!

0512 You'll Go Far If You Shoot Far

0513 Learn to Reflect, and This One Is in the Bank

Site 6: Happiness Research Lab

0601 Bet You Mist Us!

0602 Octarian Heights

0603 Torture Tour

0604 Conserve Ink—Splat Sustainably

0605 The Enemy Ink Is Lava!

0606 Keep It Rolling

0607 That Sinking Feeling

0608 Breathe In, Breathe Out

0609 Dive and Dash

0610 Mission: Fly-Fishin'

0611 Don't Tease with the Keys

0612 Enter the Stamp Gauntlet

06  The Obscurest Chiaroscurist

Finale: Alterna Space Center

Rocket 01 Alterna Space Center: Entrance

Rocket 02 Alterna Space Center Hangar

Rocket 03 Alterna Space Center Lift

Rocket 04 The Spirit Lifter: Steerage

Rocket 05 The Spirit Lifter: First Class

Rocket  1 The Ursine Anomaly - #03

Rocket  2 Return of the Mammalians

Characters

• Agent 3 - Inkling or Octoling - The playable character.
• Smallfry - Salmonid - Agent 3's companion.
• Cuttlefish - Inkling - An old war hero and the retired captain of the New Squidbeak Splatoon, who recruits Agent 3 and Smallfry.
• Agent 1 / Callie - Inkling - A member of the Squid Sisters who supports Agent 3 in Alterna.
• Agent 2 / Marie - Inkling - A member of the Squid Sisters who supports Agent 3 in Alterna.
• Captain - Inkling - The original Agent 3 and current leader of the New Squidbeak Splatoon.
• O.R.C.A. - AI - A computer system created by the scientists who built Alterna, and overseer of the missions in Alterna.
• Shiver - Octoling - A member of Deep Cut, a band and bandit trio, who serves as a minor antagonist.
• Frye - Inkling - A member of Deep Cut, a band and bandit trio, who serves as a minor antagonist.
• Big Man - Manta ray - A member of Deep Cut, a band and bandit trio, who serves as a minor antagonist.
• DJ Octavio - Octoling - The leader of the Octarian army and minor antagonist of the story.
• Mr. Grizz - Grizzly bear - CEO of Grizzco Industries and main antagonist of the story.

Enemies

Regular enemies

This table is sorted by order of appearance. Enemies marked with * are newly introduced in Splatoon 3.

Image	Name	Description	Debut
	Fuzzy Blobby Octotrooper	Octotroopers that ride a different machine resembling a gumball machine. They act and look almost identically to their regular versions but shoot a duo of shots that bounce along the ground. These can deal a lot of damage in numbers but are also susceptible to gravity.	No. 1 Octarians in the Crater? YIKES!
	Fuzzy Octocopter	Flying enemies propelled by their helmets. They hover above the ground and shoot at Agent 3 on sight, but their projectiles and general flying speed are slow, like Octotroopers.	No. 3 Boxes Locked! Keys, Please!
	Fuzzy Octotrooper	The basic grunts of the Octarian army, Octotroopers stand on small machines that allow them to shoot single, very slow ink globules. They have very little health and mobility and so are easily defeated, but may pose a threat in numbers.	No. 4 What Are They? Can We Stop Them?!
	Fuzzy Shielded Octotrooper	Octotroopers with shields in front of their machines. The shield can be destroyed after taking a lot of damage, but their exposed backsides are their weak spots, easily hit after being distracted, such as by Smallfry. Also appears in Octodiver and Twintacle Octotrooper forms.	0101 Get to Know Alterna, Your Only Choice
	Squee-G	Although incapable of dealing damage, these very rare small robots serve as nuisances, attaching to walls and automatically sucking up Agent 3's ink. They can sometimes carry items and slow down upon being attacked.	0101 Get to Know Alterna, Your Only Choice
	Octopod	Small metallic creatures that run around in sneakers. Octopods jump to attention upon seeing the player. Upon reaching them, they explode in Octarian ink, dealing some damage. They can be attacked to be defused. They appear to be Octorpedoes on legs.	0102 Octopods at Rest Tend to FLIP OUT!
	Oversized Octopod*	Giant Octopods that move and attack in a similar way to their smaller counterparts. However, they are slower but require much more damage to detonate, having a much larger blast radius as well.	0102 Octopods at Rest Tend to FLIP OUT!
	Fuzzy Octosniper	Elite enemies that shoot long, thin, and very powerful shots of ink, similar to chargers, while stationed on unmoving platforms. Like charger users, they have an extremely long line of sight but are mostly incapable of close-quarters fighting, while their shots require some time to charge and are marked with a laser line.	0104 Doors, Doors, Doors! And More! (Doors)
	Fuzzy Octocommander	Large stationary enemies that are very similar to Octosnipers. They can only rotate in place and use giant splatlings to attack quickly over a large range. However, they take a while to recharge, leaving them wide open.	0104 Doors, Doors, Doors! And More! (Doors)
	Fuzzy Rocket Octocopter	Darker versions of Octocopters that have thrusters attached to their helmets. Although they are no stronger than normal, they can quickly dodge left and right, making them a nuisance to defeat.	0109 The String's the Thing
	Fuzzy Amped Octostamp*	Stronger Octostamps that are recognisable by their headphones. They have a cover over their weak point, requiring more damage to break, and send out a damaging shockwave on contact with the ground similar to the Wave Breaker.	0110 Deadly Dance Hall—Jump, Jump!
	Fuzzy Twintacle Octotrooper	Stronger Octotroopers with two tentacles. These enemies have better mobility than the normal Octotrooper and greater ink-firing capability, similar to a splatling, but are still easy targets.	0201 Twirling, Swirling, Whirling
	Fuzzy Octomissile	Little explosive missiles with a tentacle in the middle. They spawn infinitely and burst with ink on contact, but can be defeated simply by being attacked.	0205 Tread Heavily
	Fuzzy Octozeppelin	Giant airships themed after Octarians with a single tentacle sticking out the top. They spawn infinitely, using their propellers to spray ink behind them, and are invulnerable apart from their tentacle.	0302 They Said We'd Have Flying Cars, and We Do! Kinda!
	Octowasher	Indestructible spinning torrents of ink that appear as damaging barriers. They deal fatal damage on contact and block shots, meaning they can only be avoided.	0304 Try Curling! Alterna's 11th Most Popular Athleisure Activity!
	Fuzzy Octohopper*	Bouncing Octotroopers that follow Agent 3 on sight. Although they are as weak as regular Octotroopers, they are persistent and attack with slosher-like ink flings which deal a lot of damage.	0402 Octohoppers Don't Have a Sense of Humor (and They Hate Puns)!
	Fuzzy Octoballer	Inky bowling balls populated by Octotroopers that spawn infinitely and leave a trail of ink behind them. They can only be destroyed by attacking the Octotrooper as normal.	0403 Let's Put a Pin in That
	Fuzzy Octodisco*	Flying spherical Octarians that look similar to disco balls. Instead of attacking Agent 3, they hover over other enemies and form a shield like the Big Bubbler. In this state, they can only be attacked from above, but the shield breaks if the enemy inside is defeated.	0407 Charge Now, Splat Later
	Fuzzy Octoling	Octarian variants of Inklings that act as elite forces en masse and can utilize a wide variety of main, sub, and special weapons. Dark-haired Elite Octolings are much harder to defeat and act similarly to human opponents in multiplayer modes.	0411 Stamp 'Em Out
	Fuzzy Octostamp	Cuboid, machine-like creatures with inky faces. Although they are not fast, they can leap into the air and face-plant the ground, dealing fatal damage. They can only be defeated from behind, which is exposed by their method of attack.	0411 Stamp 'Em Out
	Fuzzy Rocket Twintacle Octotrooper	Noticeably darker Twintacle Octotroopers. They have the same capabilities as normal Twintacle Octotroopers but with jet thrusters on their machines, making them capable of fast dodges.	0501 Trouble Round Every Corner
	Flooder	Huge machines on stilts that rain down Octarian ink from under them and move in set patterns. They charge at Agent 3 on sight and can defeat them instantly if not distracted by Smallfry, but their tops also act as platforms that can hold items and other mechanics. Big Flooders are even taller and harder to scale.	0505 A Compulsive Collector's Paradise
	Fuzzy Octodiver	Octotroopers wearing snorkels, which allow them to breathe under their ink. They pop out without warning to attack and can dive to hide like Agent 3. Also appears in Shielded Octotrooper and Twintacle Octotrooper forms.	0508 Making Waves with Splashdowns
	Fuzzy Octobomber	Large flying Octarians similar to improved Octocopters. They hover around and shoot Splat Bombs out of their helmets which detonate fatally one second after landing. However, they are large, slow, and unwieldy, making them obvious targets.	0509 Low Viz, High Risk
	Fuzzy Rocket Octobomber	Darker variants of Octobombers that can use the rocket thrusters on their helmets to quickly dodge to the side when being attacked. Their attack pattern has not changed, however.	0509 Low Viz, High Risk
	Fuzzy Tentakook	Extremely rare little Octarians that hide important items and give chase on sight. They use their ink-powered roller skates to cover their tracks and can drop Splat Bombs behind them. They are very fast and can only be caught by swimming in ink.	0611 Don't Tease with the Keys
	Octorpedo	Missiles filled with Octarian ink fired by Mr. Grizz. Acting like flying Octopods, they home in on Agent 3 and explode, but can be easily shot down. However, amongst the rest of the boss battle, they can serve as major distractions.	Rocket  1 The Ursine Anomaly - #03

Bosses

Image	Name	Description	Debut
	DJ Octavio and the Octobot King L3.Gs	The leader of the Octarians in his signature machine, now with added legs and new attacks to make up for no longer being powered by the Great Zapfish. Like in previous appearances, Octavio attacks with a variety of fist attacks which must be avoided or shot back to damage him. In later phases, he utilizes Ink Vac and Wave Breaker attacks as well.	Crater  Octobot King L3.Gs
	Frye and moray eels*	The first member of Deep Cut. She rides on the remains of the Octostomp out of range and attacks by shooting dozens of moray eels at Agent 3, which must be avoided or shot back to damage her. When stunned, the player must scale the Octostomp to damage her directly, after which she adds a variety of extra eel attacks to her move set.	02  The Future Stares Back
	Shiver and Master Mega*	The second member of Deep Cut and her shark, which she rides mostly out of range of attack. Although they can be damaged while circling the arena, it is easiest to attack Master Mega when it charges onto the arena like the Reefslider, at which point Shiver can be attacked directly. In later phases, they jump between ink tornadoes around the arena and attack much faster.	04  The Pursuit of the Precious
	Big Man*	The third and final member of Deep Cut. He transforms into a shadow and floats around the arena, leaving ink behind. When attacked, the shadow splits into smaller ones which attack with various bomb blasts. The real Big Man shadow is identified through the Squid Sensor, whereas fake ones explode. In later phases, the shadows attack faster and with more bomb types.	06  The Obscurest Chiaroscurist
	Mr. Grizz*	He is Ursine Anomaly #3 and CEO of Grizzco Industries who has harvested Golden Eggs and stolen the Great Zapfish to return mammals to the world through his Fuzzy Ooze. Agent 3 must dodge his many attacks and clear Fuzzy Ooze with Smallfry to be able to attack Grizz directly, after which he intensifies his attacks. In the second half of the battle, Agent 3 must work with DJ Octavio to use the Octobot King L3.Gs' Ink Vac and absorb and shoot out the Fuzzballs on Grizz's body within 3 minutes and 33 seconds, all while avoiding space debris.	Rocket  1 The Ursine Anomaly - #03

Quotes

“	SRL historian here with a pro tip. Want to learn about the weird world of Alterna AND brush up your skills with all kinds of weapons and varied terrain? Check out Story Mode! Just follow the strange old man into the Splatsville sewer to get started. Wow, new sentence. Another Story Mode tip: most stages allow you to choose from multiple weapon loadouts. So you can sharpen your skills AND take advantage of a weapon's particular strengths to survive. That said, sometimes you'll have nothing to rely on but your wits... and maybe a Zipcaster.	”
— @SplatoonNA on Twitter

“	It's not all multiplayer mayhem in #Splatoon3, you know? Dozens of single-player stages filled with unique tricks, tests and... hairy Octarians await in Story Mode.	”
— @NintendoEurope on Twitter

Badges

Main article: Badge#Story Mode

Completing certain objectives in Return of the Mammalians rewards the player with badges that they can use on their Splashtag.

Return of the Mammalians badges
	DJ Octavio Defeated!	Defeat the Octobot King L3.Gs in the Crater
	Story Mode Cleared!	Complete the Alterna Space Center sequence and see the credits
	Max Hero Level Achieved!	Collect the maximum of 99 Upgrade Points
	Max Hero Level Achieved!
	Secret Kettle Found and Cleared!	Unlock and clear After Alterna

Music

This article or section is incomplete or is missing information.

You can help the wiki by filling in the blanks.
Reason: Needs audio file for "Alterna Shimin Program M-00: Init (Test Noise)"

Gallery

Artwork

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  Mode icon

• File:S3 Return of the Mammalians logo.png

  Logo

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  Key art (vertical)

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  Key art (horizontal, no logo)

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  Agent 3 and Smallfry

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  Agent 3

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  Agent 3

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  Agent 3

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  Smallfry and Power Eggs

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  Smallfry

• 

  Smallfry

• 

  Smallfry

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  New Squidbeak Splatoon (Callie, the Captain, and Marie)

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  New Squidbeak Splatoon - Holidays 2021

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  New Squidbeak Splatoon

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  Craig Cuttlefish

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  Craig Cuttlefish

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  Octotrooper

Promotional images

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  Agent 3 with the first style of the Hero Suit

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  Agent 3 with the second style of the Hero Suit

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  An Octotrooper

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  A view of Alterna, as seen in the opening

• 
• 
• 
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  Agent 3 and Smallfry near some of the Fuzzy Ooze

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  Agent 3, immediately after touching the Fuzzy Ooze

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  Agent 3, fully trapped in Fuzzy Ooze

• Smallfry eating some Fuzzy Ooze via a Fuzzball

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  Callie, Marie, and the Captain

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  An Octarian and Smallfry

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  Cuttlefish, as seen in Splatoon 3

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  Octostamps and an Amped Octostamp in Return of the Mammalians

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  A group of Octohoppers

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  A group of Octopods with an Oversized Octopod.

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  A group of Octarians

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  Enemy Octolings

Other

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  A world map taken from the Earth's model as seen in the final boss

Screenshots

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  An image of Agent 3 wielding a Sloshing Machine, with Smallfry in the back.

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  Agent 3 battling an Octarian with the Splatana Stamper.

Similarities with Octo Expansion

Return of the Mammalians bears multiple similarities to Octo Expansion. Both stages share their name with a playable game mode within their respective Splatoon games.

Story Mode Progression

• The player can choose between different non-Hero weapons.
• Both modes have a similar interface, a variety of mission conditions and heightened freedom as opposed to the previous two story modes' linear progression.
• Both modes have a form of currency
  • Return of the Mammalians has Power Eggs.
  • Octo Expansion has CQ Points.
  • Use of in-game currency is required to unlock or attempt missions, progressing the campaign.
• In Return of the Mammalians, Power Eggs are also used to clear Fuzzy Ooze that blocks the way.
• Both modes have a key NPC that guides the player throughout an area or splats them if they fail certain objectives (such as running out of ink or time).
  • Return of the Mammalians has O.R.C.A.
  • Octo Expansion has C.Q. Cumber
• Both modes are underground, far below the sea level of Earth.

Final Stage

In both Octo Expansion and Return of the Mammalians, the player must face a continuous final stage before attempting to face the final boss of each campaign. The start of both stages removes the player's weapons and requires the player to re-equip their gear along the way. Both stages also feature an "unlimited use" section that allows special weapon use without losing special power.

Return of the Mammalians

The final stage in Return of the Mammalians is the Alterna Space Center with the initial Alterna Space Center: Entrance starting the player with no gear.

The section for unlimited special weapon use is The Spirit Lifter: First Class with Zipcaster as the weapon.

Octo Expansion

The final stage in Octo Expansion is Deepsea Metro Escape with the initial areas of Coccyx Phase and Villi Phase starting the player with no gear.

The section for unlimited special weapon use is Diaphragm Phase with Inkjet as the weapon.

Penultimate Missions

Both of these sequences feature two songs written by the game's main idol group.

The penultimate mission uses different music for each section: the first plays a modified version of the enemy's theme, and the second plays the idol's theme.

In both final missions, the successful final attack grows so powerful that the attack damages the game UI in some way.

In both final missions, being splatted or running out of time will show an additional cutscene of the world being destroyed before showing the 'Continue?' screen.

Return of the Mammalians

The first mission is The Ursine Anomaly - #03, using Bear with Me as the theme.

The final mission is Return of the Mammalians (mission), using Calamari Inkantation 3MIX as the theme. DJ Octavio's Ink Vac destroys the game UI as the attack power increases.

Octo Expansion

The first mission is Sanitized Agent 3 using Splattack! (Octo) as the the theme.

The final mission is Turf War (Octo Expansion) using Fly Octo Fly ~ Ebb & Flow (Octo) as the theme. Pearl's Princess Cannon destroys the game UI as the attack power increases.

Changes after completing the mode

After the player completes Return of the Mammalians, the following changes occur:

• The Great Zapfish can be seen in Splatsville.
• Li'l Judd starts to wear a headset.
• Deep Cut in Splatsville and the Squid Sisters in Inkopolis Plaza both have more enthusiastic animations when the player zooms in on them in their studios.
• The statue used by Mr. Grizz in Grizzco buildings changes from a bear eating a fish to a large fish eating a miniature bear, though his dialogue icon remains the same. The original Mr. Grizz statue appears in Alterna behind the Squid Sisters Camp, and can be interacted with to replay the final Alterna Space Center section or watch the credits again via memories.
• Cuttlefish, in his dried-up form, joins the Squid Sisters and the Captain at the Squid Sisters Camp, where he can be spoken to.
• The Spirit Lifter in Alterna is replaced by a near-identical rocket that is blue rather than orange.
• If the player has fully surveyed all of Alterna by visiting all of the space on the map, the Shel-drone appears on the platform near the Squid Sisters Camp.
• If the player has completed every level in Alterna, the secret kettle for After Alterna appears at the spot where the player first arrived in Alterna.

Trivia

• Return of the Mammalians is the first single-player mode in the Splatoon series:
  • to not have "Octo" in its title.
  • to not feature any levels based on multiplayer stages.
  • to not feature multiple levels focused on Octolings, and to not introduce the Octolings via a mini-cutscene.
• Return of the Mammalians is the only single-player mode in the Splatoon series in which the player can play as either an Inkling or an Octoling, without being restricted to one or the other.
  • Cuttlefish's quotes about Octarians and squid references do not change when the player is an Octoling.
• Agent 3 has two styles of the Hero Suit. A post on Nintendo's official website hinted that they are "each suited to different situations".
  • In-game, the torn down version is a "standard" form while the other is part of the upgradable Hero set.
• Many mysterious sounds can be heard in Alterna, but are hard to hear and are distorted. This ambient noise includes announcement messages sent over a loudspeaker system to the Alterna Space Center, with various notification sounds and human speech in English reporting on the status of the rocket launch.
• The Booyah Bomb and Tacticooler special weapons are the only ones in the game that were available at the game's launch to not appear in any way in Return of the Mammalians. Big Bubbler, while not available for use by the player, is used by Octolings in the final section of After Alterna.
• Before Version 1.1.1, if the player closed the game or entered sleep mode during Deep Cut's news broadcast directly after beating the final boss, they would be forced to replay the entire final section due to a glitch.
• As level progression in Return of the Mammalians is linked to collecting Power Eggs rather than completing levels, the ending can be reached by completing a minimum of 15 levels (the five Crater levels, the three Deep Cut bosses, and the seven stages in the final Alterna Space Center sequence). This is the fewest required levels of any single-player mode in the series, with one fewer than the Octo Expansion.

Names in other languages

Language	Name	Meaning
Japanese	哺乳類の帰還 honyūrui no kikan	Return of the Mammals
Dutch	Terugkeer van de Mammalianen	Return of the Mammalians
French	Le retour des mammifériens	The return of the Mammalians
German	Rückkehr der Mammalianer	Return of the Mammalians
Italian	Il ritorno dei mammiferiani	The return of the mammalians
Russian	Возвращение молокоедов Vozvrashcheniye molokoyedov	The return of the milk eaters
Spanish	El regreso de los mamiferoides	The return of the mammalians
Chinese (Simplified)	哺乳类的回归 Bǔrǔlèi de huíguī	Return of the Mammals
Chinese (Traditional)	哺乳類的回歸 Bǔrǔlèi de huíguī	Return of the Mammals
Korean	포유류의 귀환 poyuryu-ui gwihwan	Return of the Mammals

External links

• Splatoon 3 – "Return of the Mammalians" – Nintendo Switch