Don't Have

Undead Servant

When this creature enters, create a 2/2 black Zombie creature token for each card named Undead Servant in your graveyard.

Have

Highborn Ghoul

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Diregraf Scavenger

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, exile up to one target card from a graveyard. If a creature card was exiled this way, each opponent loses 2 life and you gain 2 life.

Wight of Precinct Six

This creature gets +1/+1 for each creature card in your opponents' graveyards.

Putrid Imp

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

Victim of Night

Destroy target non-Vampire, non-Werewolf, non-Zombie creature.

Carnophage

At the beginning of your upkeep, tap this creature unless you pay 1 life.

Swamp

Cradle of the Accursed

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Create a 2/2 black Zombie creature token. Activate only as a sorcery.

Butcher Ghoul

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Moan of the Unhallowed

Create two 2/2 black Zombie creature tokens.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)