From the publisher's website:
Deal a dungeon! DungeonMorph cards are a deck of 90 2.5" x 2.5" cards with all 90 DungeonMorph designs on the front. The back of each card is the mirrored version of the front allowing for even more combinations.
Dungeonmorph Cards were produced as part of the Dungeonmorph Dice project (catalogued as a version of the generic Dice item.)