Blackcleave Goblin

Haste
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Rotting Rats

When Rotting Rats enters the battlefield, each player discards a card.
Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Herald of the Dreadhorde

When Herald of the Dreadhorde dies, amass Zombies 2. (Put two +1/+1 counters 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.)

Vedalken Ghoul

Whenever Vedalken Ghoul becomes blocked, defending player loses 4 life.

Walking Dead

Armored Skaab

When Armored Skaab enters the battlefield, mill four cards.

Returned Phalanx

Defender
{1}{U}: Returned Phalanx can attack this turn as though it didn't have defender.

Accursed Centaur

When Accursed Centaur enters the battlefield, sacrifice a creature.

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.

Cadaverous Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{1}{B}{B}: Regenerate Cadaverous Knight.

Mass of Ghouls

Metathran Zombie

Festering Goblin

When Festering Goblin dies, target creature gets -1/-1 until end of turn.

Zombie Outlander

Jhessian Zombies

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Islandcycling {2}, swampcycling {2} ({2}, Discard this card: Search your library for an Island or Swamp card, reveal it, put it into your hand, then shuffle.)

Sedraxis Alchemist

When Sedraxis Alchemist enters the battlefield, if you control a blue permanent, return target nonland permanent to its owner's hand.

Gravedigger

When Gravedigger enters the battlefield, you may return target creature card from your graveyard to your hand.

Gempalm Polluter

Cycling {B}{B} ({B}{B}, Discard this card: Draw a card.)
When you cycle Gempalm Polluter, you may have target player lose life equal to the number of Zombies on the battlefield.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

Roofstalker Wight

{1}{U}: Roofstalker Wight gains flying until end of turn.

Diregraf Captain

Deathtouch
Other Zombie creatures you control get +1/+1.
Whenever another Zombie you control dies, target opponent loses 1 life.

Fleshbag Marauder

When Fleshbag Marauder enters the battlefield, each player sacrifices a creature.

Grixis Slavedriver

When Grixis Slavedriver leaves the battlefield, create a 2/2 black Zombie creature token.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Vodalian Zombie

Drowned

Ghoulraiser

When Ghoulraiser enters the battlefield, return a Zombie card at random from your graveyard to your hand.

Lazotep Reaver

When Lazotep Reaver enters the battlefield, 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.)

Walking Corpse

Dripping Dead

Dripping Dead can't block.
Whenever Dripping Dead deals combat damage to a creature, destroy that creature. It can't be regenerated.