Imposter in Pokémon X & Y

The Pokémon transforms itself into the Pokémon it’s facing.

Transforms into the facing opponent when entering battle.

When sent into battle, this Pokémon transforms into the opponent directly opposite it in Double or Triple Battles. In a horde it copies the rightmost opponent. This is a fixed position, not a random opponent; if no opponent occupies the required position, it does not transform. It cannot copy a Pokémon behind a substitute, under Illusion, or already transformed.