Amiibo

amiibo are figurines produced by Nintendo that are equipped with Near-Field Communication technology and can be used in a variety of Wii U and Nintendo 3DS games, including Splatoon.

Splatoon
On April 1, 2015, Nintendo announced in a Nintendo Direct that Splatoon would be receiving three different amiibo on May 29, 2015. These amiibo, when scanned in Inkopolis Plaza, unlock twenty different challenges with five unlockable boss challenges in Octo Valley and new exclusive gear to wear into battle. The three amiibo that have been announced are the Inkling Boy amiibo, the Inkling Girl amiibo, and the Inkling Squid amiibo with the Squid only available as part of the three-pack in North America, and in Europe exclusively in the Splatoon + Inkling Squid amiibo bundle.

Over a year after, a second wave of figures was announced, including the Squid Sisters, Callie and Marie, and three reskins of the amiibo from the previous wave.

Gameplay
The amiibo case is located at the southeastern corner of Inkopolis and it appears as the packaging amiibo traditionally come in. When scanning an amiibo (if the amiibo is registered) a flurry of paint circles the inside as the corresponding amiibo forms inside of it. The character introduces themselves and lays down guidelines for their challenges.

Each Wave 1 amiibo features twenty challenges if the single-player mode, Octo Valley, has been completed. The first challenge gives the player six hundred cash as a reward, with the reward increasing by one hundred more cash for each next challenge (i.e. one mission reward is 1000 cash, while the next mission reward is 1100 cash). Each challenge can be completed again, though for only a reward of 100 cash. When three challenges in the same row are completed, the fourth challenge for that set is unlocked, being the boss for its corresponding area in Octo Valley. As opposed to a monetary reward, the boss challenges provide three pieces of gear for the first three bosses, a minigame for the fourth, and a weapon blueprint for the final boss.

The Squid Sisters amiibo allow the user to view concerts in the plaza, similar to a Splatfest, and the functionality of the other three is unknown.

Inkling Boy
"Sup, playa?! Thanks a ton for callin' me up! I heard you've been makin' waves around the city. And I've got an inkling that you're the type of Inkling who's up for a challenge. Wanna give one of my roller challenges a go? I heard you've been doing work in Octo Valley. Wearin' that crazy getup, wreckin' Octobros and junk! That's when I knew for sure that you've got what it takes to try my challenges. All you gotta do is beat those same missions using a roller weapon! So are you game? I've got some dope rewards lined up if you can pull it off!"

- Inkling Boy

The Inkling Boy amiibo was released on May 29, 2015 along with Splatoon. It can be used to unlock 20 Roller challenges in Octo Valley and will provide the player with an exclusive character piece after every four challenges completed. After completing all challenges, the player will complete the set and receive the exclusive Samurai Gear along with the Squid Racer minigame and the Hero Roller Replica blueprints. It can be purchased individually or in a pack of three with the Inkling Girl and Inkling Squid amiibo in North America.

The original Inkling Boy amiibo is a light-skinned Inkling with dark blue tentacles and blue eyes. He wears the Fake Contacts, Zink Layered LS, and Purple Hi-Horses and carries the Splattershot.

The recolored Inkling Boy has dark skin, purple tentacles, and orange eyes. He wears the Fake Contacts, the Choco Layered LS, and the Gold Hi-Horses and carries the Tentatek Splattershot.

Challenges
These Octo Valley challenges must be completed with the Splat Roller:

Inkling Girl
"Dude! Lemme tell you I am SO glad you called me! I'm pickin' up a fresh vibe from you. Tell me...are you a fan of charger weapons? Cuz that's my kinda thing—making up challenges where you gotta use chargers! Are you game? Come to think of it...you've been pokin' around down in Octo Valley, yeah? Yup, I saw you in that rad outfit, fighting those...things. It looked super fun! But you know what would be even radder? If you used a charger weapon! That's my challenge to you. Clear missions with a charger, and I'll hook ya up!"

- Inkling Girl

The Inkling Girl amiibo was released on May 29, 2015 alongside Splatoon. It can be used to unlock 20 Charger challenges in Octo Valley and rewards the player with an exclusive costume piece for every four challenges completed. After completing all challenges, the player will complete the set and receive the exclusive School Gear along with the Squidball minigame and the Hero Charger Replica blueprints. It can be purchased individually or in a pack of three with the Inkling Boy and Inkling Squid amiibo in North America.

The original Inkling Girl amiibo is a light-skinned Inkling with orange tentacles and orange eyes. She wears the Fake Contacts, White Tee, and Pink Trainers and carries the Splattershot.

The recolored Inkling Girl's skin color remains unchanged, but her tentacles are lime green and her eyes are magenta. She wears the Fake Contacts, the Black Tee, and the Black Trainers and carries the Tentatek Splattershot.

Challenges
These Octo Valley challenges must be completed with the Splat Charger:

Inkling Squid
"Why, hello there, friendo! Thank you kindly for summoning me here. I can see you're just itching for some way to test your skills. Well, I've been thinking up some challenges that might float your boat! What do you say? Think you're up to the task? By the by, I hear you've been making quite a splash over in Octo Valley. In fact, I saw you at it! Wearing outlandish gear and fighting odd creatures! I think that proves you have what it takes to attempt my challenges. What do you have to lose? I have some nice rewards for you if you win!"

- Inkling Squid

The Inkling Squid amiibo was released on May 29, 2015. It can be used to unlock 16 Kraken and 4 limited-Ink challenges, and shooter challenges in Octo Valley and will provide the player with an exclusive costume piece after every four challenges completed. After completing all the challenges, the player will complete the set and receive the exclusive Power Gear along with the Squid Beatz minigame and the Hero Shot Replica blueprints. It is available exclusively for purchase in a pack of three with the Inkling Boy amiibo and the Inkling Girl amiibo in North America, and exclusively in a bundle with the main game in Europe.

The original Inkling Squid amiibo is a green Inkling in squid form, and the recolored Inkling Squid is orange.

Challenges
The Inkling Squid amiibo allows players to complete specific Octo Valley missions in two ways: some can be completed as a Kraken with limited time, and others must be completed with limited ink. In the Kraken Challenges, the player is given the ability to turn into a Kraken instead of a Squid for the entirety of the level. In limited ink challenges, the player is given three or four full Ink Tanks to complete the level, but ink cannot be replenished. The challenges are as follows:

Squid Sisters
Amiibo of Callie and Marie will be released on July 8th, 2016. They can be used to unlock exclusive in-game Squid Sisters concerts.

amiibo tap: Nintendo's Greatest Bits
amiibo tap: Nintendo's Greatest Bits, known in Europe and Australia as amiibo Touch & Play: Nintendo Classics Highlights, is a downloadable application for Wii U that allows amiibo owners to try out classic NES and SNES games. All amiibo figures work with the application.

Captain Toad: Treasure Tracker
In Captain Toad: Treasure Tracker, the Splatoon amiibo figures can be used for a 1-UP Mushroom. Most of the other amiibo figures can be used for this as well, however.

Hyrule Warriors
The Splatoon amiibo figures can be tapped once a day in Hyrule Warriors for a weapon rated 3 stars or lower, a Rupee bonus, or a crafting material bonus. Most of the other amiibo figures can be used for this as well, however.

Mario Party 10
The Splatoon amiibo figures can be tapped in Mario Party 10 for a Scratch Bonus and Mario Party Points. Most of the other amiibo figures can be used for this as well, however.

Mini Mario and Friends: amiibo Challenge
In Mini Mario & Friends: amiibo Challenge, any Splatoon amiibo figure can be used to start the game. This is the same for all other amiibo, though. However certain amiibo from the Super Mario series unlock extra stages and have special abilities as well.

Pokkén Tournament
The Splatoon amiibo figures can be tapped once a day in Pokkén Tournament for an avatar costume item, a title, or a Poké Gold bonus. Up to 5 amiibo rewards can be claimed per day. Most of the other amiibo figures can be used for this as well, however.

Super Mario Maker
Super Mario Maker features Mario skins of numerous Nintendo characters through amiibo. Splatoon amiibo will grant the player with a costume resembling the scanned character. The Inkling Squid can assume humanoid form and is revealed to be a dark-skinned male with a Splat Roller, the Studio Headphones, the White Layered LS, and what appears to be the Cream Basics.

Yoshi's Woolly World
Yoshi's Woolly World features Yoshi skins of numerous Nintendo characters through amiibo. Splatoon amiibo will grant the player with a pattern resembling the scanned character.

Profiles and bios
"Bring an Inkling amiibo™ figure home and open cool extras in your game."

- Splatoon's official website

"Tap a Splatoon-series amiibo™ figure to your Wii U GamePad controller. Complete the challenges to access exclusive gear for your Inkling!"

- Splatoon's official website

Trivia

 * The Inkopolis Plaza out of bounds glitch reveals that the back of the amiibo case at the southeastern corner does have a texture and looks like the back of real amiibo packaging, except the words are written in Inkling.
 * The Inkling Girl's amiibo is the basis for its trophies in Super Smash Bros. for Nintendo 3DS and Wii U.