Moldering Gym / Weight Room - Duskmourn: House of Horror (DSK)

Enchantment - Room

Common - Duskmourn: House of Horror (DSK)

(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Moldering Gym - 2, Green

When you unlock this door, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Weight Room - 5, Green

When you unlock this door, manifest dread, then put three +1/+1 counters on that creature.