“Hoopa is a Mythical Pokémon that you cannot meet through ordinary gameplay in the world of Pokémon Omega Ruby and Pokémon Alpha Sapphire. It is the 720th Pokémon to be added to the Pokédex, and it would appear that it can change form.
Hoopa Unbound is the new and truest form of Hoopa, which until now has had its power sealed away. The rings it carries have the power to bend dimensions and are said to allow it to seize anything in the world.
After its transformation, Hoopa Unbound is far larger than it was in its previous appearance. It is easy to recognize by its six huge arms, and it is carrying a greater number of its signature dimension-bending rings.