Lurking Predators

Whenever an opponent casts a spell, reveal the top card of your library. If it's a creature card, put it onto the battlefield. Otherwise, you may put that card on the bottom of your library.

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

Call of the Wild

{2}{G}{G}: Reveal the top card of your library. If it's a creature card, put it onto the battlefield. Otherwise, put it into your graveyard.

Aether Membrane

Defender; reach (This creature can block creatures with flying.)
Whenever this creature blocks a creature, return that creature to its owner's hand at end of combat.

Monstrous Vortex

Whenever you cast a creature spell with power 5 or greater, discover X, where X is that spell's mana value. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Vicious Shadows

Whenever a creature dies, you may have this enchantment deal damage to target player equal to the number of cards in that player's hand.