Putrid Goblin

Persist (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.)

Counterspell

Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Diregraf Captain

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

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Swamp

Champion of the Perished

Whenever another Zombie enters the battlefield under your control, put a +1/+1 counter on Champion of the Perished.

Thran Vigil

Whenever one or more artifact and/or creature cards leave your graveyard during your turn, put a +1/+1 counter on target creature you control.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Gravecrawler

Gravecrawler can't block.
You may cast Gravecrawler from your graveyard as long as you control a Zombie.

Island

Plague Belcher

Menace
When Plague Belcher enters the battlefield, put two -1/-1 counters on target creature you control.
Whenever another Zombie you control dies, each opponent loses 1 life.

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")