Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Dark Ritual

New Card

Evil Presence

Stitcher's Supplier

When this creature enters or dies, mill three cards.

Grave Titan

Deathtouch
Whenever this creature enters or attacks, create two 2/2 black Zombie creature tokens.

Carrion Feeder

This creature can't block.
Sacrifice a creature: Put a +1/+1 counter on this creature.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to that card's mana value.

Crawl from the Cellar

Return target creature card from your graveyard to your hand. Put a +1/+1 counter on up to one target Zombie you control.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.)

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Filth

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
As long as this card is in your graveyard and you control a Swamp, creatures you control have swampwalk.

Mox Jet

Royal Assassin

Gravecrawler

This creature can't block.
You may cast this card from your graveyard as long as you control a Zombie.

Altar of Dementia

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

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Urborg, Tomb or Yawgmoth

All lands are swamps in addition to their other types. 

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Midnight Charm

Choose one —
• Midnight Charm deals 1 damage to target creature and you gain 1 life.
• Target creature gains first strike until end of turn.
• Tap target creature.

Quantity Change +

Swamp

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Zombie Master

Other Zombie creatures have swampwalk. (They can't be blocked as long as defending player controls a Swamp.)
Other Zombies have "{B}: Regenerate this permanent."