Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Boneyard Wurm

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

Llanowar Elves

Nyx Weaver

Reach
At the beginning of your upkeep, mill two cards. (Put the top two cards of your library into your graveyard.)
{1}{B}{G}, Exile Nyx Weaver: Return target card from your graveyard to your hand.

Satyr Wayfinder

When Satyr Wayfinder enters, 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.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Ghoultree

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

Wight of the Reliquary

Vigilance
Wight of the Reliquary gets +1/+1 for each creature card in your graveyard.
{T}, Sacrifice another creature: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

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, instead tap it, remove it from combat, and heal all damage on it.)

Sol Ring

Garden of Freyalise

As Garden of Freyalise enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {G}.

Disciple of Freyalise

When Disciple of Freyalise enters, you may sacrifice another creature. If you do, you gain X life and draw X cards, where X is that creature's power.

Disciple of Freyalise // Garden of Freyalise

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.)

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Elvish Mystic

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Ripples of Undeath

At the beginning of your first main phase, mill three cards. Then you may pay {1} and 3 life. If you do, put a card from among those cards into your hand.

Village Rites

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

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

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.

Ashnod's Altar

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

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.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

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.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Fyndhorn Elves

Skull Prophet

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

Dark Ritual

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Elves of Deep Shadow

{T}: Add {B}. Elves of Deep Shadow deals 1 damage to you.

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Lord of Extinction

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

Aftermath Analyst

When Aftermath Analyst enters, mill three cards.
{3}{G}, Sacrifice Aftermath Analyst: Return all land cards from your graveyard to the battlefield tapped.

Birds of Paradise

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.