Secret Ninja Attack

Secret Ninja Attack (, The Shinobi's Hidden Secret), is Greninja's Final Smash.

Overview
In this Final Smash, Greninja sends one or more foes airborne by using : hitting them with a, then overwhelms its opponent with slashes, kicks, and palm strikes in front of the moon. Greninja then readies a final blow to meteor smash the foe. It is similar to Ike's Great Aether.

The Final Smash deals a total of 52% damage: 2% if the opponent(s) are caught by the Mat Block, 5% for the Mat Block flip, 2% for each rapid attack, and 15% for the final blow.

Aside from the initial Mat Block, the attack is visually identical to Zoroark's Fury Swipes attack; however, the Secret Ninja Attack deals significantly more damage, and the final blow cannot be teched (except in Ultimate).

In Super Smash Bros. Ultimate, Greninja transforms into Ash-Greninja for the Final Smash.

Origin
Greninja activates this move by striking downward at a tatami, a type of mat, to flip it upward and hit opponents, referencing (known in Japan as Tatami Flip), formerly one of its s in the Pokémon games. Mat Block possesses the ability to defend the user's side of the field from all attacks used after it; however, unlike other protective moves, it does not possess increased priority and thus will fail if used last in the turn. It is also only able to be used the first turn after Greninja enters the field; at all other times, it will fail. While not named after it, the move's overall aesthetics share thematic similarities with, a move Greninja can learn by leveling up in the games.

Ash-Greninja
In the Pokémon anime, upon his final evolution, 's Greninja obtained a unique ability called. It is similar to Mega Evolution but relies on being in sync with Ash rather than a Mega Stone. This transformation caused Greninja to temporarily take on a design based on Ash and his Kalos outfit, as well as producing a psychic bond with Ash. The transformation later appeared in the main series games with a special Greninja with only obtainable through the Sun and Moon demo, where the transformation would activate upon defeating an opponent directly. Ash-Greninja has higher base stats than regular Greninja and if Ash-Greninja uses Water Shuriken, the move's power becomes 20 (rather than the usual 15) and it always hits three times. The transformation would later be removed in Pokémon Scarlet and Violet with Battle Bond only boosting Greninja's attack, special attack and speed. Ash-Greninja is referenced in 's house as a painting however.

Trivia

 * In stages with platforms that reside at high altitudes, such as Palutena's Temple, characters not caught in the Final Smash are able to show up in the animation. These characters are fully mobile and do not appear as silhouettes, unlike Greninja and any opponents it caught.
 * Although the trophy depicts a full moon, the final smash actually only uses a graphic of half of the moon, which can be seen by pausing and moving the camera (Wii U only). In the 3DS, more of the moon is visible when the camera is focused on Greninja, but one can't see where the moon ends in normal gameplay.