(Grassy Catacombs isn't a spell.) At the beginning of your end step, if you didn't cast any spells this turn, Grassy Catacombs deals 1 damage to you. Grassy Catacombs is indestructible. (Destroy effects and lethal damage don't destroy it.) : Add  or to your mana pool. Sacrifice Grassy Catacombs: Add  or to your mana pool.