The Pokémon TCG: Black & White Dark Explorers TCG expansion was released on May 9th, 2012. Pictures from this set have been added to an Imageboard thread.

Press Release - March 14th, 2012

As you explore the darkness, the Pokémon TCG: Black and White — Dark Explorers expansion ushers in the return of the immensely powerful Darkrai-EX and a lineup of Darkness-type Pokémon, like Zoroark, Umbreon, and Sableye, to knock your opponent’s lights out! Playing with Trainer cards like Dark Patch, included in the expansion to help give Darkness-type decks an edge you’ll not only navigate the darkness, you’ll rule it!

The fifth Pokémon TCG: Black and White expansion also continues an impressive run of featuring Unova and non-Unova region Pokémon-EX cards, more powerful Pokémon that deliver devastating attacks to your opponents. Darkrai-EX is joined by Tornadus-EX, Kyogre-EX, Raikou-EX, and Groudon-EX, all featured as Pokémon-EX cards and rare Ultra full-art Pokémon-EX cards!


Key features of the new Pokémon TCG: Black & White—Dark Explorers expansion includes:

• Six more Pokémon-EX from the Unova region and beyond
• New strategies for Darkness-type Pokémon
• More than 100 cards, including three Shiny Secret rare cards
• More Restored Pokémon options
• First Eevee cards since the Pokémon TCG: HS—Undaunted
• Parallel foil card guaranteed in each booster pack

Each new theme deck and booster pack includes an in-pack code card that unlocks virtual cards for play in the Pokémon Trading Card Game Online. Expand your personal deck and battle against others from around the world!

Source: https://www.pokemon.com/us/pokemon-tcg/black-white-dark-explorers