Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

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. (Put the top two cards of your library into your graveyard.)

Impervious Greatwurm

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Indestructible

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.)

Phyrexian Dreadnought

Trample
When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

Yargle and Multani

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Boneyard Wurm

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

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)

Soul's Fire

Target creature you control deals damage equal to its power to any target.

Malignus

Malignus's power and toughness are each equal to half the highest life total among your opponents, rounded up.
Damage that would be dealt by this creature can't be prevented.

Awakened Amalgam

Awakened Amalgam's power and toughness are each equal to the number of differently named lands you control.

Nova Chaser

Trample
Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Daemogoth Titan

Whenever this creature attacks or blocks, sacrifice a creature.

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.

Lord of Extinction

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

Coram, the Undertaker

Coram gets +X/+0, where X is the greatest power among creature cards in all graveyards.
Whenever Coram attacks, each player mills a card.
During each of your turns, you may play a land and cast a spell from among cards in graveyards that were put there from libraries this turn.