This description comes from Wikipedia

Greninja (¥²¥Ã¥³¥¦¥¬ Gekk¨­ga?), known as the Ninja Pok¨¦mon, is the final evolved from of Froakie. With its new Dark typing it becomes swift and elusive as a ninja. Its signature ability is compressing water into special Water Shuriken that it uses in its attacks.[2][10] It is also able to learn Extrasensory, making it able to hold its own against Fighting Types. Greninja will be a playable character in Super Smash Bros. for Nintendo 3DS and Wii U.