Rathi Trapper

Quicksand

{T}: Add {C}.
{T}, Sacrifice Quicksand: Target attacking creature without flying gets -1/-2 until end of turn.

Phyrexian Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

Deathbloom Thallid

When Deathbloom Thallid dies, create a 1/1 green Saproling creature token.

Cast Down

Grasp of Darkness

Target creature gets -4/-4 until end of turn.

Stab Wound

Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Order of the Ebon Hand

Protection from white
{B}: Order of the Ebon Hand gains first strike until end of turn.
{B}{B}: Order of the Ebon Hand gets +1/+0 until end of turn.

Blight-Breath Catoblepas

When Blight-Breath Catoblepas enters, target creature an opponent controls gets -X/-X until end of turn, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Covenant of Blood

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Covenant of Blood deals 4 damage to any target and you gain 4 life.

Dogged Pursuit

At the beginning of your end step, each opponent loses 1 life and you gain 1 life.

Driver of the Dead

When this creature dies, return target creature card with mana value 2 or less from your graveyard to the battlefield.

Eyeblight Massacre

Non-Elf creatures get -2/-2 until end of turn.

Ichor Slick

Target creature gets -3/-3 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)
Madness {3}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Festering Mummy

When Festering Mummy dies, you may put a -1/-1 counter on target creature.

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters, you become the monarch.

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Elderfang Disciple

When Elderfang Disciple enters, each opponent discards a card.

Hymn to Tourach

Target player discards two cards at random.

Basilica Screecher

Flying
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Perilous Myr

When Perilous Myr dies, it deals 2 damage to any target.

Lazotep Reaver

When Lazotep Reaver enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)