Skull Prophet

{T}: Add {B} or {G}.
{T}: Mill two cards.

Yargle, Glutton of Urborg

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.

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Phyrexian Devourer

When Phyrexian Devourer's power is 7 or greater, sacrifice it.
Exile the top card of your library: Put X +1/+1 counters on Phyrexian Devourer, where X is the exiled card's mana value.

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.

Terravore

Trample
Terravore's power and toughness are each equal to the number of land cards in all graveyards.

Yargle and Multani

Ghoultree

This spell costs {1} less to cast for each creature card in your graveyard.

Lord of Extinction

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