Wii U Pro Controller

The Wii U Pro Controller is a controller of the Wii U that can only be used in the Battle Dojo mode in Splatoon.

Description
The Wii U Pro Controller is an optional accessory for the Wii U that replaces the Wii Classic Controller Pro, and was replaced by the Switch Pro Controller. It has the same overall button layout as the Wii U GamePad, in a traditional controller layout, however it lacks motion control sensors, camera, NFC Pad, headphone jack and touchscreen. It's resembles an Xbox 360 controller.

Battle Dojo
In the Battle Dojo, one player can use the Wii U Pro Controller to play on the TV, to pop as many balloon as they can, against their opponent, using the Wii U GamePad. This is the only functionality available for this controller.

Features

 *  and : The stick is used primarily to move the player's Inkling forward, backward, left, and right. The  stick, on the other hand, is used for aiming, and controls which direction the player looks. The  stick is used for menus, such as the weapon select and pause screen.
 * : The button allows players to transform into squids. In this form, Inklings are able to move faster through their own ink and jump farther.
 * : The button allows players to splatter ink using their weapon.
 * : The button allows players to use their sub weapon.
 * : The button causes the player's Inkling to jump.
 * : The button resets the camera angle, allowing for quick corrections.
 * : The button is used in menus to select specific actions and options.
 * : The button is used to deselect a chosen weapon in the weapon select screen.
 * : The can be used in Battle Dojo menus like the  stick.
 * : The button is used to pause and resume in in a Battle Dojo match, and adjust the controls on the weapon select screen.

Trivia

 * Multiple Pro Controllers and a Wii U GamePad can be seen inside the Battle Dojo hanging on the wall. There are three white controllers,a black controller and a white GamePad on the left side and two black controllers on the right side.
 * Battle Dojo matches can also be played with a combination of Wii U Pro Controller and a Wii Remote Plus or Wii Remote with a Wii MotionPlus accessory, which was hinted at in the 26th Sunken Scroll. (pictured below) This allows the player using the Wii U Pro controller to have motion controls. To perform this, the player must hold down on the, hold down , and press and  as described on the Splatoon Tumblr, Live from Squid Research Lab.