Mutavault

{T}: Add {C}.
{1}: This land becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Stitcher's Supplier

When this creature enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Swamp

Altar of Dementia

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

Bloodghast

This creature can't block.
This creature has haste as long as an opponent has 10 or less life.
Landfall — Whenever a land you control enters, you may return this card from your graveyard to the battlefield.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Hogaak, Arisen Necropolis

You can't spend mana to cast this spell.
Convoke, delve (Each creature you tap while casting this spell pays for {1} or one mana of that creature's color. Each card you exile from your graveyard pays for {1}.)
You may cast this card from your graveyard.
Trample

Pithing Needle

As this artifact enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Asmoranomardicadaistinaculdacar

As long as you've discarded a card this turn, you may pay {B/R} to cast this spell.
When Asmoranomardicadaistinaculdacar enters, you may search your library for a card named The Underworld Cookbook, reveal it, put it into your hand, then shuffle.
Sacrifice two Foods: Target creature deals 6 damage to itself.

Plague Engineer

Deathtouch
As this creature enters, choose a creature type.
Creatures of the chosen type your opponents control get -1/-1.

Cabal Therapy

Choose a nonland card name. Target player reveals their hand and discards all cards with that name.
Flashback—Sacrifice a creature. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Gravecrawler

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

The Underworld Cookbook

{T}, Discard a card: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{4}, {T}, Sacrifice this artifact: Return target creature card from your graveyard to your hand.

Vengevine

Haste
Whenever you cast a spell, if it's the second creature spell you cast this turn, you may return this card from your graveyard to the battlefield.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Surgical Extraction

({B/P} can be paid with either {B} or 2 life.)
Choose target card in a graveyard other than a basic land card. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles.

Putrid Imp

Discard a card: This creature gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, this creature gets +1/+1 and can't block.

Bridge from Below

Whenever a nontoken creature is put into your graveyard from the battlefield, if this card is in your graveyard, create a 2/2 black Zombie creature token.
When a creature is put into an opponent's graveyard from the battlefield, if this card is in your graveyard, exile this card.

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

Undead Butler

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
When this creature dies, you may exile it. When you do, return target creature card from your graveyard to your hand.

Carrion Feeder

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