Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target 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.

Boneyard Wurm

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

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.)

Blood for Bones

As an additional cost to cast this spell, sacrifice a creature.
Return a creature card from your graveyard to the battlefield, then return another creature card from your graveyard to your hand.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Jarad's Orders

Search your library for up to two creature cards and reveal them. Put one into your hand and the other into your graveyard. Then shuffle.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Momentous Fall

As an additional cost to cast this spell, sacrifice a creature.
You draw cards equal to the sacrificed creature's power, then you gain life equal to its toughness.

Costly Plunder

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Izoni, Thousand-Eyed

Undergrowth — When Izoni, Thousand-Eyed enters, create a 1/1 black and green Insect creature token for each creature card in your graveyard.
{B}{G}, Sacrifice another creature: You gain 1 life and draw a card.

Mazirek, Kraul Death Priest

Flying
Whenever a player sacrifices another permanent, put a +1/+1 counter on each creature you control.

Bonecaller Cleric

{3}{B}, Sacrifice Bonecaller Cleric: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Savra, Queen of the Golgari

Whenever you sacrifice a black creature, you may pay 2 life. If you do, each other player sacrifices a creature of their choice.
Whenever you sacrifice a green creature, you may gain 2 life.

Death Pit Offering

When Death Pit Offering enters, sacrifice all creatures you control.
Creatures you control get +2/+2.

Grist, the Hunger Tide

As long as Grist, the Hunger Tide isn't on the battlefield, it's a 1/1 Insect creature in addition to its other types.
+1: Create a 1/1 black and green Insect creature token, then mill a card. If an Insect card was milled this way, put a loyalty counter on Grist and repeat this process.
−2: You may sacrifice a creature. When you do, destroy target creature or planeswalker.
−5: Each opponent loses life equal to the number of creature cards in your graveyard.