Blood Scrivener

If you would draw a card while you have no cards in hand, instead you draw two cards and you lose 1 life.

Lake of the Dead

If Lake of the Dead would enter, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Zombie Trailblazer

Tap an untapped Zombie you control: Target land becomes a Swamp until end of turn.
Tap an untapped Zombie you control: Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Undead Gladiator

{1}{B}, Discard a card: Return Undead Gladiator from your graveyard to your hand. Activate only during your upkeep.
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)

Boneknitter

{1}{B}: Regenerate target Zombie.
Morph {2}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Shepherd of Rot

{T}: Each player loses 1 life for each Zombie on the battlefield.

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.)

Dark Ritual

Champion of the Perished

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

Carrion Feeder

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

Unholy Grotto

{T}: Add {C}.
{B}, {T}: Put target Zombie card from your graveyard on top of your library.

Swamp

Gempalm Polluter

Cycling {B}{B} ({B}{B}, Discard this card: Draw a card.)
When you cycle Gempalm Polluter, you may have target player lose life equal to the number of Zombies on the battlefield.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Profane Insight

You draw a card and you lose 1 life. (Then exile this card. You may cast the creature later from exile.)

Foulmire Knight

Foulmire Knight // Profane Insight

Gravecrawler

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