Splash the Greninja is a male Greninja, the current leader of a group of Mobian Pokemon called the Megastone Rogues, and an unknowing good friend of Fox the Brave in The Legend of Fox the Brave. He is mostly the strong, silent type, but is smart and even a bit sympathetic for someone of his backstory. Splash is the titular protagonist of Splash's Raid, and a supporting protagonist of both parts of Tai's Travels, in addition to having a minor appearance in Austin's Adventures, and a brief cameo in both Austin's Flight and A Brother's Search. He acts as sort of a voice of reason on the Alliance, and is well respected despite his evil lineage.
As Frogadier: Splash resembles a short anthropomorphic frog. His upper half is darker blue along with his face, the "crests" behind his eyes; his hands and toes are dark blue as well. Splash's lower half, his arms, legs, and eyelids are lighter blue. He has a thick collar of white "frubbles" around his neck, and white fingers and nostrils. He has black eyes with yellow sclera, and a long, pale scar running diagonally from just by his left eye to down near the front of his right one.
As Greninja: Splash resembles a slightly taller anthropomorphic blue frog. His face, the sides of his face-crests, his belly, and the webbing between his fingers and toes are tan, and he has a long blue crest in the middle of his face. A sort-of web between his three face crests is pale blue, and the bubble-like spots on his elbows and knees are white. He has his tongue wrapped around his neck like a scarf, and has pinkish-red eyes. Splash doesn't have any apparel, and simply wears a black wrist-com on his right wrist.
As Master Splash: He greatly resembles the "Ash-Greninja" transformation from the Pokemon anime series, with a few minor differences: The "crests" Splash gains are orange, as is the one on his face, and he gains an additional orange "crest" on each elbow. He still gains a giant Water Shuriken on his back.
Splash is a very stoic fellow, rarely expressing emotion(similar to Locke). He acts as a voice of reason for the Storming Alliance, but will not hesitate to fight if it means defending his Teammates or his family. Despite his lack of expressiveness, Splash is still an understanding person, willing to help someone in trouble regardless of his own safety.
Legends of the Megastone Rogues
Tai's Travels, Part 1/Nero's Vengeance(former half): The younger son of Nya, a Frogadier, and the evil Greninja Nero, Splash and his brother Clamshell were born in the Megastone Rogues, and brought up with help from Tai the Charizard, the leader at the time, and Nya's other love interest. However, the pair were kidnapped during one of the Outsiders'(led by Nero) many attacks on the Megastone Rogues' camp. Wanting to keep the peace as well as his own sons and those of one of his warriors, Tai agreed to let Nero keep his sons, much to Nya's anger and hurt.
Tai's Travels, Part 2/Nero's Vengeance(latter half): After an unknown time-during which Nero scarred Splash's face when the latter was a Frogadier-Splash escaped and fled back to the Megastone Rogues, later reuniting with his mother. Sadly, while on patrol, Nya was killed by Nero, giving Splash the confidence to evolve into Greninja and see past his evil lineage.
Land of Nightmares: Splash first appears when Tai arrives in the Land of Shadows to save Fox, as he is seen riding on Tai's back. Later, when Tai is killed, Splash is greeted by the Spirit of his mother when the Spirits in the Stars come down to retrieve their new arrival. Splash then becomes the new leader of the Megastone Rogues, eager to live up to the mighty picture that Tai had.
World of Shadows: Splash first appears when he is helping an injured Fox stretch. He gently presses down on Fox's shoulders with his foot until the irate Fox snaps at him. Later, he accompanies Fox to Dark Mobius(the titular "World of Shadows"), and helps him out in the ensuing struggle. Splash is next to Fox when they undergo the Fusion Fox transformation for the first time.
Secrets of the Dark World: Part 1: Splash is first seen alongside Fox by Braveheart as they face down a large group of Prelates. He is later mentioned by Dark Enerjak when he mockingly tells Braveheart that he saw the Prime Zone's Fox and Splash.
A Brother's Search: Though unnamed, Splash makes a brief cameo in this story when he tells Michael where Austin was. He is mentioned to be a Greninja with a nasty scar on his face, but he nevertheless directs Michael, saying that Locke took him to The Storming Base.
Being a Pokemon, Splash can spawn Water Shurikens out of seemingly nowhere. His current moveset consists of Water Shuriken, Double Team, Cut, and Aerial Ace, though he has only been seen using Water Shuriken on more than one occasion. When in his Master Splash form, Splash can use any move whatsoever, mostly through the giant Shuriken he gains in this form.
Splash's Ability is currently unknown, since it has never been said what his or his mother's Ability is, and his father's Ability has been described as Protean in one instance, then Torrent in another. Like all Greninja, Splash is fast and stealthy, and can use his tongue like a hand to grab things and ledges out of reach of his hands, or as a weapon, to trip his enemies or(as in Struggle Against the Shadows when he fought Sonic.EXE) to slap his enemies.
Splash can be incredibly stealthy and speedy, which is to be expected since he is essentially a ninja frog. He can also use his attacks in various ways, such as to fool enemies, pound them relentlessly, or to catch someone's attention.
As with all Pokemon of his Type(Water and Dark), Splash is weak to Electric, Bug, Fairy, and Fighting. He resists Fire, Ice, Steel, Dark, and Water, and is immune to Psychic altogether. Unlike Fire, Rock, and Ground-Type Pokemon that have appeared in the series, Splash's weaknesses have never showed up as a fear at any point in time.