Lhurgoyf

Lhurgoyf's power is equal to the number of creature cards in all graveyards and its toughness is equal to that number plus 1.

Golgari Grave-Troll

Golgari Grave-Troll enters with a +1/+1 counter on it for each creature card in your graveyard.
{1}, Remove a +1/+1 counter from Golgari Grave-Troll: Regenerate Golgari Grave-Troll.
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.)

Bonehoard

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +X/+X, where X is the number of creature cards in all graveyards.
Equip {2}

Boneyard Mycodrax

Boneyard Mycodrax's power and toughness are each equal to the number of other creature cards in your graveyard.
Scavenge {4}{B} ({4}{B}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Drakestown Forgotten

Drakestown Forgotten enters with X +1/+1 counters on it, where X is the number of creature cards in all graveyards.
{2}{B}, Remove a +1/+1 counter from Drakestown Forgotten: Target creature gets -1/-1 until end of turn.

Moldgraf Millipede

When Moldgraf Millipede enters, mill three cards, then put a +1/+1 counter on Moldgraf Millipede for each creature card in your graveyard. (To mill three cards, put the top three cards of your library into 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.)
Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

Apocalypse Demon

Flying
Apocalypse Demon's power and toughness are each equal to the number of cards in your graveyard.
At the beginning of your upkeep, tap Apocalypse Demon unless you sacrifice another creature.

Jarad, Golgari Lich Lord

Jarad, Golgari Lich Lord 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 Jarad from your graveyard to your hand.

Revenant

Flying
Revenant's power and toughness are each equal to the number of creature cards in your graveyard.

Fiend Artisan

This creature gets +1/+1 for each creature card in your graveyard.
{X}{B/G}, {T}, Sacrifice another creature: Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Blight Titan

Deathtouch
Whenever Blight Titan enters or attacks, mill two cards, then incubate X, where X is the number of creature cards in your graveyard. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

Bloodsworn Knight

Bloodsworn Knight's power and toughness are each equal to the number of creature cards in your graveyard.
{1}{B}, Discard a card: Bloodsworn Knight gains indestructible until end of turn. Tap it. (Damage and effects that say "destroy" don't destroy it.)

Bloodsworn Squire

{1}{B}, Discard a card: Bloodsworn Squire gains indestructible until end of turn. Tap it. Then if there are four or more creature cards in your graveyard, transform Bloodsworn Squire. (Damage and effects that say "destroy" don't destroy it.)

Bloodsworn Squire // Bloodsworn Knight

Elephant Resurgence

Each player creates a green Elephant creature token. Those creatures have "This creature's power and toughness are each equal to the number of creature cards in its controller's graveyard."

Splinterfright

Trample
Splinterfright's power and toughness are each equal to the number of creature cards in your graveyard.
At the beginning of your upkeep, mill two cards.

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.

Boneyard Wurm

Boneyard Wurm's power and toughness are each equal to the number of creature cards in your graveyard.

Arbor Elf

Golgari Raiders

Haste
Undergrowth — Golgari Raiders enters with a +1/+1 counter on it for each creature card in your graveyard.

Mortivore

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

Zombie Mob

Zombie Mob enters with a +1/+1 counter on it for each creature card in your graveyard.
When Zombie Mob enters, exile all creature cards from your graveyard.

Svogthos, the Restless Tomb

{T}: Add {C}.
{3}{B}{G}: Until end of turn, Svogthos, the Restless Tomb becomes a black and green Plant Zombie creature with "This creature's power and toughness are each equal to the number of creature cards in your graveyard." It's still a land.

Frankenstein's Monster

As Frankenstein's Monster enters, exile X creature cards from your graveyard. If you can't, put Frankenstein's Monster into its owner's graveyard instead of onto the battlefield. For each creature card exiled this way, Frankenstein's Monster enters with a +2/+0, +1/+1, or +0/+2 counter on it.

Necrogoyf

Necrogoyf's power is equal to the number of creature cards in all graveyards.
At the beginning of each player's upkeep, that player discards a card.
Madness {1}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Lord of Extinction

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