Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Recurring Nightmare

Sacrifice a creature, Return this enchantment to its owner's hand: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Survival of the Fittest

{G}, Discard a creature card: Search your library for a creature card, reveal that card, put it into your hand, then shuffle.