Deathcap Cultivator

{T}: Add {B} or {G}.
Delirium — This creature has deathtouch as long as there are four or more card types among cards in your graveyard.

World Shaper

Whenever this creature attacks, you may mill three cards.
When this creature dies, return all land cards from your graveyard to the battlefield tapped.

Grim Flayer

Trample
Whenever this creature deals combat damage to a player, surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Delirium — This creature gets +2/+2 as long as there are four or more card types among cards in your graveyard.

Nighthowler

Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
This creature and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

Skull Prophet

{T}: Add {B} or {G}.
{T}: Mill two cards. (Put the top two cards of your library into your graveyard.)

Squirming Emergence

Fathomless descent — Return to the battlefield target nonland permanent card in your graveyard with mana value less than or equal to the number of permanent cards in your graveyard.

Mortivore

Mortivore's power and toughness are each equal to the number of creature cards in all graveyards.
{B}: Regenerate this creature. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Jarad, Golgari Lich Lord

Jarad gets +1/+1 for each creature card in your graveyard.
{1}{B}{G}, Sacrifice another creature: Each opponent loses life equal to the sacrificed creature's power.
Sacrifice a Swamp and a Forest: Return this card from your graveyard to your hand.

Souls of the Lost

As an additional cost to cast this spell, discard a card or sacrifice a permanent.
Fathomless descent — Souls of the Lost's power is equal to the number of permanent cards in your graveyard and its toughness is equal to that number plus 1.

Old Stickfingers

When you cast this spell, reveal cards from the top of your library until you reveal X creature cards. Put all creature cards revealed this way into your graveyard, then put the rest on the bottom of your library in a random order.
Old Stickfingers's power and toughness are each equal to the number of creature cards in your graveyard.

Stinkweed Imp

Flying
Whenever this creature deals combat damage to a creature, destroy that creature.
Dredge 5 (If you would draw a card, you may mill five cards instead. If you do, return this card from your graveyard to your hand.)

Yargle and Multani

Underrealm Lich

If you would draw a card, instead look at the top three cards of your library, then put one into your hand and the rest into your graveyard.
Pay 4 life: This creature gains indestructible until end of turn. Tap it.

Nyx Weaver

Reach
At the beginning of your upkeep, mill two cards. (Put the top two cards of your library into your graveyard.)
{1}{B}{G}, Exile this creature: Return target card from your graveyard to your hand.

Underground Mortuary

({T}: Add {B} or {G}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Satyr Wayfinder

When this creature enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

Rise of the Witch-king

Each player sacrifices a creature of their choice. If you sacrificed a creature this way, you may return another permanent card from your graveyard to the battlefield.

Sakura-Tribe Elder

Sacrifice this creature: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Terror Tide

Fathomless descent — All creatures get -X/-X until end of turn, where X is the number of permanent cards in your graveyard.

Grisly Salvage

Reveal the top five cards of your library. You may put a creature or land card from among them into your hand. Put the rest into your graveyard.

Lord of Extinction

Lord of Extinction's power and toughness are each equal to the number of cards in all graveyards.

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.

Golgari Grave-Troll

This creature enters with a +1/+1 counter on it for each creature card in your graveyard.
{1}, Remove a +1/+1 counter from this creature: Regenerate this creature.
Dredge 6 (If you would draw a card, you may mill six cards instead. If you do, return this card from your graveyard to your hand.)

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Brawn

Trample
As long as this card is in your graveyard and you control a Forest, creatures you control have trample.