Attach Fluffy Berry to 1 of your Pokémon (excluding Pokémon-ex and Pokémon that has Dark or an owner in its name) that doesn't already have a Pokémon Tool attached to it. If the Pokémon Fluffy Berry is attached to is Pokémon-ex or has Dark or an owner in its name, discard Fluffy Berry.

As long as Fluffy Berry is attached to a Pokémon, that Pokémon's Retreat Cost is 0.