Don't Have

Eccentric Farmer

When Eccentric Farmer enters, mill three cards, then you may return a land card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Coram, the Undertaker

Coram, the Undertaker 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.

Have

Kagha, Shadow Archdruid

Whenever Kagha, Shadow Archdruid attacks, it gains deathtouch until end of turn. Mill two cards. (Put the top two cards of your library into your graveyard.)
Once during each of your turns, you may play a land or cast a permanent spell from among cards in your graveyard that were put there from your library this turn.

Mountain

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Roots of Wisdom

Mill three cards, then return a land card or Elf card from your graveyard to your hand. If you can't, draw a card. (To mill a card, put the top card of your library into your graveyard.)

Entropic Decay

Mill four cards. (Then exile this card. You may cast the creature later from exile.)

Gray Slaad

As long as there are four or more creature cards in your graveyard, Gray Slaad has menace and deathtouch.

Gray Slaad // Entropic Decay

Brawn

Trample
As long as Brawn is in your graveyard and you control a Forest, creatures you control have trample.

Swamp

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Yargle and Multani

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Circle of the Land Druid

When Circle of the Land Druid enters, you may mill four cards. (You may put the top four cards of your library into your graveyard.)
Natural Recovery — When Circle of the Land Druid dies, return target land card from your graveyard to your hand.

Gruul Signet

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Restless Vents

Restless Vents enters tapped.
{T}: Add {B} or {R}.
{1}{B}{R}: Until end of turn, Restless Vents becomes a 2/3 black and red Insect creature with menace. It's still a land.
Whenever Restless Vents attacks, you may discard a card. If you do, draw a card.

Bone Shards

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

Skull Prophet

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

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Forest

Dig Deep

Choose target creature. Mill four cards, then put a +1/+1 counter on that creature for each creature card milled this way.

Colossal Badger

When Colossal Badger enters, you gain 3 life.

Colossal Badger // Dig Deep

Gruul Turf

Gruul Turf enters tapped.
When Gruul Turf enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Druidic Ritual

You may mill three cards. Then return up to one creature card and up to one land card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

The Grim Captain

Menace, trample, lifelink, hexproof
Whenever The Grim Captain attacks, each opponent sacrifices a nonland permanent of their choice. Then you may put an exiled creature card used to craft The Grim Captain onto the battlefield under your control tapped and attacking.

Throne of the Grim Captain

{T}: Mill two cards.
Craft with a Dinosaur, a Merfolk, a Pirate, and a Vampire {4} ({4}, Exile this artifact, Exile the four from among permanents you control and/or cards in your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Throne of the Grim Captain // The Grim Captain

Another Chance

You may mill two cards. Then return up to two creature cards from your graveyard to your hand. (To mill two cards, put the top two cards of your library into your graveyard.)

Lord of Extinction

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