Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

Giant Spider

Reach (This creature can block creatures with flying.)

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Forest

Giant Growth

Target creature gets +3/+3 until end of turn.

Spined Wurm

Naturalize

Bloodthrone Vampire

Sacrifice a creature: This creature gets +2/+2 until end of turn.

Royal Assassin

Captivating Vampire

Other Vampire creatures you control get +1/+1.
Tap five untapped Vampires you control: Gain control of target creature. It becomes a Vampire in addition to its other types.

Barony Vampire

Rise from the Grave

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

Howling Banshee

Flying
When this creature enters, each player loses 3 life.

Swamp

Sorcerer's Strongbox

{2}, {T}: Flip a coin. If you win the flip, sacrifice this artifact and draw three cards.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Nature's Spiral

Return target permanent card from your graveyard to your hand.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Doom Blade

Child of Night

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.