Inkay was confirmed as a Poké Ball item in Super Smash Bros. for Wii U and 3DS in the Greninja reveal trailer alongside many other Pokémon. Inkay uses the move Topsy-Turvy causing other fighters to trip.
Inkay may look like a Water-type Pokémon, but it's actually a Dark/Psychic type! Once it has reached the proper level, Inkay can evolve into Malamar if you hold the Nintendo 3DS upside down. In Smash Bros., its Tospy-Turvy move will flip anyone who wanders too close upside down. Watch out!