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.

Shambling Shell

Sacrifice Shambling Shell: Put a +1/+1 counter on target creature.
Dredge 3 (If you would draw a card, you may mill three cards instead. If you do, return this card from your graveyard to your hand.)

Eternal Witness

When Eternal Witness enters the battlefield, you may return target card 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.

Bonehoard

Living weapon (When this Equipment enters the battlefield, 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}

Raise Dead

Return target creature card from your graveyard to your hand.

Mortivore

Mortivore's power and toughness are each equal to the number of creature cards in all graveyards.
{B}: Regenerate Mortivore.

Mazirek, Kraul Death Priest

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

Jungle Hollow

Jungle Hollow enters the battlefield tapped.
When Jungle Hollow enters the battlefield, you gain 1 life.
{T}: Add {B} or {G}.

Swamp

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.

Time of Need

Search your library for a legendary creature card, reveal it, put it into your hand, then shuffle.

Forest

Satyr Wayfinder

When Satyr Wayfinder enters the battlefield, 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.

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.