Necromancer's Covenant

When Necromancer's Covenant enters the battlefield, exile all creature cards from target player's graveyard, then create a 2/2 black Zombie creature token for each card exiled this way.
Zombies you control have lifelink.

Ripples of Undeath

At the beginning of your precombat main phase, mill three cards. Then you may pay {1} and 3 life. If you do, put a card from among those cards into your hand.

Anikthea, Hand of Erebos

Menace
Other enchantment creatures you control have menace.
Whenever Anikthea enters the battlefield or attacks, exile up to one target non-Aura enchantment card from your graveyard. Create a token that's a copy of that card, except it's a 3/3 black Zombie creature in addition to its other types.

Dreadhorde Invasion

At the beginning of your upkeep, you lose 1 life and 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.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.

Graf Harvest

Zombies you control have menace. (They can't be blocked except by two or more creatures.)
{3}{B}, Exile a creature card from your graveyard: Create a 2/2 black Zombie creature token.

Quest for the Gravelord

Whenever a creature dies, you may put a quest counter on Quest for the Gravelord.
Remove three quest counters from Quest for the Gravelord and sacrifice it: Create a 5/5 black Zombie Giant creature token.

Endless Ranks of the Dead

At the beginning of your upkeep, create X 2/2 black Zombie creature tokens, where X is half the number of Zombies you control, rounded down.

Liliana's Mastery

Zombies you control get +1/+1.
When Liliana's Mastery enters the battlefield, create two 2/2 black Zombie creature tokens.

Mindless Conscription

When Mindless Conscription enters the battlefield and whenever you draw your third card each turn, amass Zombies 3. (Put three +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.)

Calix, Guided by Fate

Constellation — Whenever Calix, Guided by Fate or another enchantment enters the battlefield under your control, put a +1/+1 counter on target creature.
Whenever Calix or an enchanted creature you control deals combat damage to a player, you may create a token that's a copy of a nonlegendary enchantment you control. Do this only once each turn.

Sarcomancy

When Sarcomancy enters the battlefield, create a 2/2 black Zombie creature token.
At the beginning of your upkeep, if there are no Zombies on the battlefield, Sarcomancy deals 1 damage to you.

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment enters the battlefield under your control, each opponent loses 1 life.

Nylea's Colossus

Constellation — Whenever Nylea's Colossus or another enchantment enters the battlefield under your control, double target creature's power and toughness until end of turn.

Doomwake Giant

Constellation — Whenever Doomwake Giant or another enchantment enters the battlefield under your control, creatures your opponents control get -1/-1 until end of turn.