As long as your opponent has any Pokémon-ex as his or her Active Pokémon, the Retreat Cost for Rattata is 0.
The Pokémon Company International is not responsible for the content of any linked website that is not operated by The Pokémon Company International. Please note that these websites' privacy policies and security practices may differ from The Pokémon Company International's standards.
Your request could not be completed. Please try again. If the problem persists, please contact Customer Support.