EX Hidden Legends was released in June 2004, with 101 cards and 1 secret card, the set was the fifth expansion in the EX Series. The set features Generation III Pokemon and Pokemon ex and is based on Pokemon Ruby & Sapphire, with a focus on Legendary Pokemon - Regirock, Regice, and Registeel. In this set the Dot Strip for e-Reader was removed from this set and so the bottom border of the card was returned to normal sizing and Reverse Holofoil cards received a new design.
The secret card in this set was Groudon #102, and other cards to check out in this set are Ninetales ex #96 & Dark Celebi Reverse Holo #4.