Death Baron

Skeletons you control and other Zombies you control get +1/+1 and have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)

Deadly Plot

Choose one —
• Destroy target creature or planeswalker.
• Return target Zombie creature card from your graveyard to the battlefield tapped.

Xu-Ifit, Osteoharmonist

{T}: Return target creature card from your graveyard to the battlefield. It's a Skeleton in addition to its other types and has no abilities. Activate only as a sorcery.

Unstoppable Slasher

Deathtouch
Whenever this creature deals combat damage to a player, they lose half their life, rounded up.
When this creature dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.

Engine Rat

Deathtouch
{5}{B}: Each opponent loses 2 life.

Dread Summons

Each player mills X cards. For each creature card put into a graveyard this way, you create a tapped 2/2 black Zombie creature token. (To mill a card, a player puts the top card of their library into their graveyard.)

Cursecloth Wrappings

Zombies you control get +1/+1.
{T}: Target creature card in your graveyard gains embalm until end of turn. The embalm cost is equal to its mana cost. (Exile that card and pay its embalm cost: Create a token that's a copy of it, except it's a white Zombie in addition to its other types and has no mana cost. Embalm only as a sorcery.)

Swamp

Cemetery Recruitment

Return target creature card from your graveyard to your hand. If it's a Zombie card, draw a card.

Zul Ashur, Lich Lord

Ward—Pay 2 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2 life.)
{T}: You may cast target Zombie creature card from your graveyard this turn.